Pyrometer issue
- Thread starter eleblanc
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- Thread starter
- #22
I'm not sure what you mean by sheath (outside of the probe?), but i've check continuity, form the exhaust pipe to both wires of the thermocouple and i had continuity on both. Un fortunatly i didn't check out of the box and only once installed. But i was very carefull, there is a sleeve the probe goes in and it is fit. But i f*** the probe again, i don't see how it could stay non conductive to the motor with all that vibration from the motor even if i manage to put it in without damaging it.
Anyhow i still have the problem even after changing the probe.
Anyhow i still have the problem even after changing the probe.
i still think the problem has to do with the converter, sorry if i sound like a broken record. Could you try and connect the pyrometer to one of the 12 volt batteries (specifically the battery that is directly connected to ground) temporarily to see if anything changes.
Good Luck.
Good Luck.
- Thread starter
- #24
Sure will do tomorrow
I have had a similar problem with my 70 and it turned out to be a loose contact within my fuse block that I wired up for 12 volt. Just an Idea...
Hope this Helps
-Noah
Hope this Helps
-Noah
- Thread starter
- #26
Gauge ground to the body and 12V from the first battery and i was having the same problem.....
disconnect the alternator for a minute and try it. actually i guess you just have to turn the vehicle off. Just wondering if a dodgy voltage regulator could cause this, but the symptons of your gauge seem to be a little bit beyond that,
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eleblanc,
Your problem is intermittent power or ground. I can see that in the video.
Take off the power wires and use you multimeter, hook it up. See if the voltage come on and off really quickly.
Also take your probe and hook up to the ground wire, then to ground. Do the same check with continuity. See if it goes on and off.
When I pull the fuse out of my power source to my Autometer gauge I get the same drop in the needle.
You must have a loose power connection.
Don't let it keep doing that or your gauge will be fawked.
Your problem is intermittent power or ground. I can see that in the video.
Take off the power wires and use you multimeter, hook it up. See if the voltage come on and off really quickly.
Also take your probe and hook up to the ground wire, then to ground. Do the same check with continuity. See if it goes on and off.
When I pull the fuse out of my power source to my Autometer gauge I get the same drop in the needle.
You must have a loose power connection.
Don't let it keep doing that or your gauge will be fawked.
- Thread starter
- #29
Doubt i havfe something loose on the power, i try to connect 12V+ of the gauge at multiple place, direct on the converter, direct to the battery and was always having the same thing. What i didn't do is change the negative out of the gauge some place else then the body. I will try directly on the - of the battery.
I'm not sure what you mean by
No its disconnected until i find the problem.
the thermocouple wireS should be connected only to the gauge, if they are grounded inside the gauge is a possibility, but i am guessing that they have a braided metal sheath and stainless probe, which are meant to be in contact with the metal parts of the cruiser but not the thermocouple wires. The thermocouple itself i believe is designed to be basically a variable resistance(like a dimmer switch), and the gauge will essentially be a fine tuned amp meter. The gauge will send power through the probe, the current will be proportional (or inversly proportional) to the resistance of the thermocouple, which is a direct result of heat. So the change in amperage of the thermocouple will cause the needle in the gauge to deflect.
(most simple ammeter gauges are basically a electro magnet coil that repels a piece of iron attached to the needle)
I think the gauge you have is pretty high end so it probally a bit more complicated than this.
having a bouncing needle usually means you have a bouncing power source, and that can be caused by poor + wiring, or poorly connected ground, and sometimes a faulty voltage regulator can cause a fluctuating power source. I believe this is the point brownbear is trying to get across to you.
Having the needle go into the negative is usually caused by having the voltage reversed, the electromagnet in the gauge attracts the magnet part on the needle instead of repeling it.
Sorry if this information is redundant
(most simple ammeter gauges are basically a electro magnet coil that repels a piece of iron attached to the needle)
I think the gauge you have is pretty high end so it probally a bit more complicated than this.
having a bouncing needle usually means you have a bouncing power source, and that can be caused by poor + wiring, or poorly connected ground, and sometimes a faulty voltage regulator can cause a fluctuating power source. I believe this is the point brownbear is trying to get across to you.
Having the needle go into the negative is usually caused by having the voltage reversed, the electromagnet in the gauge attracts the magnet part on the needle instead of repeling it.
Sorry if this information is redundant
- Thread starter
- #32
Here is a interesting test i just did,
Since i have a other thermocouple, i took the first one i got with the gauge kit and screwed it directly on the gauge and use a lighter to heat it up. Well i got the temp to rise to 600 deg F with no issue. I then took the thermocouple and ground it to the frame, i made sure with a light tester that current could go through. And each time i touched the body with the sheath the needle moved slightly for less then a second, but no crazyness like the video. Next I did the same thing but with the engine running, with the sheath always in contact with the frame i raise rpm to see if the problem occur....well it didn't! Now i'm puzzled...
The kit comes with the probe with 12" of wire, and a extension about 10' long. Each end of the extension has screw type terminal. So after i got the extension installed i used the two small screw supplied to hook it up to the probe, when was time to screw the other end on the gauge i realise i had the extension was reverse because the terminal at each end do not have the same size hole. So the end i had for the gauge had too small hole in the terminal. So i decided to cut the terminal and put and weld new bigger ones, instead of installing the extension under the dash again. The thermocouple wires are red and yellow, same for the extension, so i got that match. But could this extension can only be installed one way?
Anyhow my next test will be to remove the gauge from the dash, go under the hood, hook the power on the battery and then hook the gauge directly on the thermocouple wires and see what happens....Maybe the extension is cut someplace..
Since i have a other thermocouple, i took the first one i got with the gauge kit and screwed it directly on the gauge and use a lighter to heat it up. Well i got the temp to rise to 600 deg F with no issue. I then took the thermocouple and ground it to the frame, i made sure with a light tester that current could go through. And each time i touched the body with the sheath the needle moved slightly for less then a second, but no crazyness like the video. Next I did the same thing but with the engine running, with the sheath always in contact with the frame i raise rpm to see if the problem occur....well it didn't! Now i'm puzzled...
The kit comes with the probe with 12" of wire, and a extension about 10' long. Each end of the extension has screw type terminal. So after i got the extension installed i used the two small screw supplied to hook it up to the probe, when was time to screw the other end on the gauge i realise i had the extension was reverse because the terminal at each end do not have the same size hole. So the end i had for the gauge had too small hole in the terminal. So i decided to cut the terminal and put and weld new bigger ones, instead of installing the extension under the dash again. The thermocouple wires are red and yellow, same for the extension, so i got that match. But could this extension can only be installed one way?
Anyhow my next test will be to remove the gauge from the dash, go under the hood, hook the power on the battery and then hook the gauge directly on the thermocouple wires and see what happens....Maybe the extension is cut someplace..
Sorry my post was confusing. When I meant to take your probe(I meant on mulitmeter) and try checking to see of your ground was intermitten.
If your sure about the power connections, and ground. Just return the gauge to the shop you bought it and try another.
Did you have the gauge long? Could be an internal fault.
If your sure about the power connections, and ground. Just return the gauge to the shop you bought it and try another.
Did you have the gauge long? Could be an internal fault.
What other battery? + more advice
I assume that you mean the high side battery... (?)
On my North American spec' BJ4x vehicles, the lowside battery of the 24V system, i.e. the one with its ground attached to the frame, is installed on the passenger side of the vehicle.
The highside battery, i.e. where the positive is +24V relative to the frame, is installed on the driver side of the vehicle.
Please confirm exactly what you mean by "my other truck battery" as this could mean either of the BJ43 batteries or a completely different truck.
For confirmation:
1. I don't think the thermocouple sheath should have continuity with the thermocouple wires. Please confirm this with Autometer.
2. Based on Autometer's website, it would appear that they do use K-type thermocouples. In this case, the different metals used in the thermocouple wires generate a very small voltage as a function of temperature (see Wikipedia) and the meter will amplify this. Thermocouples are not the same as RTD sensors which change resistance as a function of temperature. Typically RTD sensors are used in lower temperature and thermocouples for high temperature measurements.
3. Yes, the extension wire colours must match the thermocouple wires. If they don't, you will create 2 more additional thermocouple junctions and this will screw up the true reading you are trying to make.
4. It is not advisable to "weld" new connectors to the extension cable or use other wire, this is asking for trouble if you aren't careful matching the connections (incidental thermocouple points being made in addition to the original). Typically in instrumentation circles, the metals used in thermocouple connectors are the same metals as used in the thermocouple wires.
5. The sensor MUST be installed with the correct polarity. If not, the higher the temperature, the lower the gauge reading.
Further suggestions:
1. Reread the installation instructions for the Autometer gauge paying special attention to the instructions for power, ground and sensor installation.
2. If not alread carried out, start with the basics, remove gauge / meter from instrument panel, connect gauge ground to lowside battery negative terminal, connect gauge 12V power to lowside battery positive terminal, connect thermocouple sensor to gauge (uninstalled) and observe reading behaviour with & without engine running using a lighter to provide heat. I assume that this test can be performed with no abnormal behaviour. I suggest measuring the voltage with a multimeter between the lowside negative terminal and the location you want to install the thermocouple. I almost guarantee that this is non-zero and fluctuating under the conditions you observe the odd behaviour.
3. As per 2 above, reinstall thermocouple into location you want the temperature to be measured and leave the gauge connected to the lowside battery. If the poor, noisy readings return, you either have a problem with:
A. Thermocouple defective (wires grounded to sheath, likely).
B. Gauge defective (unlikely)
C. Poor battery connections between batteries and batteries to vehicle. Check voltages for fluctuation with a multimeter when the vehicle is running and check voltage of lowside battery negative terminal to frame where the ground strap is installed. If you get a significant voltage (say >0.5V) or fluctuating badly, check your vehicles ground strap and clean the connections.
D. Battery(ies) could be in need of replacement. (I came across a non-vehicular battery last weekend that charged fine, under small 100 mA current load used for closing a relay, worked just fine but couldn't handle larger currents (1.5A) that it had handled last Summer. The voltage crashed under the larger load, dropping the relay used to connect the load, the battery voltage recovered, relay closed connecting the load again and the crash repeated at high frequency with an audible buzz). Suggest borrowing another likely good battery and install for test purposes.
Generally, with electrical problems:
1. Start with the basics and start at the beginning (in this case the lowside battery)
2. Always make a note of what you have tried with the results (it saves going round in circles.
3. Make no assumptions and always recheck someone elses work if the problem persists. Just because they said they tested something, doesn't mean that they did it correctly.
4. Take a logical approach and always start with checking the power source to the faulty item and work from there.
Apologies, but to repeat myself, thermocouples generate very small signal voltages and electronics used to measure thermocouples generally don't like to have the thermocouple wires grounded ESPECIALLY in a noisy vehicle environment where ground potentials shift dependant on where you measure and under what vehicle operation.
Did Autometer support ever get back to you? If so, what did you ask and what did they say?
Do you have a model number for the meter? Pics of the install location & thermocouple would help me understand your problem better.
Apologies for the lengthy post...
I assume that you mean the high side battery... (?)
On my North American spec' BJ4x vehicles, the lowside battery of the 24V system, i.e. the one with its ground attached to the frame, is installed on the passenger side of the vehicle.
The highside battery, i.e. where the positive is +24V relative to the frame, is installed on the driver side of the vehicle.
Please confirm exactly what you mean by "my other truck battery" as this could mean either of the BJ43 batteries or a completely different truck.
For confirmation:
1. I don't think the thermocouple sheath should have continuity with the thermocouple wires. Please confirm this with Autometer.
2. Based on Autometer's website, it would appear that they do use K-type thermocouples. In this case, the different metals used in the thermocouple wires generate a very small voltage as a function of temperature (see Wikipedia) and the meter will amplify this. Thermocouples are not the same as RTD sensors which change resistance as a function of temperature. Typically RTD sensors are used in lower temperature and thermocouples for high temperature measurements.
3. Yes, the extension wire colours must match the thermocouple wires. If they don't, you will create 2 more additional thermocouple junctions and this will screw up the true reading you are trying to make.
4. It is not advisable to "weld" new connectors to the extension cable or use other wire, this is asking for trouble if you aren't careful matching the connections (incidental thermocouple points being made in addition to the original). Typically in instrumentation circles, the metals used in thermocouple connectors are the same metals as used in the thermocouple wires.
5. The sensor MUST be installed with the correct polarity. If not, the higher the temperature, the lower the gauge reading.
Further suggestions:
1. Reread the installation instructions for the Autometer gauge paying special attention to the instructions for power, ground and sensor installation.
2. If not alread carried out, start with the basics, remove gauge / meter from instrument panel, connect gauge ground to lowside battery negative terminal, connect gauge 12V power to lowside battery positive terminal, connect thermocouple sensor to gauge (uninstalled) and observe reading behaviour with & without engine running using a lighter to provide heat. I assume that this test can be performed with no abnormal behaviour. I suggest measuring the voltage with a multimeter between the lowside negative terminal and the location you want to install the thermocouple. I almost guarantee that this is non-zero and fluctuating under the conditions you observe the odd behaviour.
3. As per 2 above, reinstall thermocouple into location you want the temperature to be measured and leave the gauge connected to the lowside battery. If the poor, noisy readings return, you either have a problem with:
A. Thermocouple defective (wires grounded to sheath, likely).
B. Gauge defective (unlikely)
C. Poor battery connections between batteries and batteries to vehicle. Check voltages for fluctuation with a multimeter when the vehicle is running and check voltage of lowside battery negative terminal to frame where the ground strap is installed. If you get a significant voltage (say >0.5V) or fluctuating badly, check your vehicles ground strap and clean the connections.
D. Battery(ies) could be in need of replacement. (I came across a non-vehicular battery last weekend that charged fine, under small 100 mA current load used for closing a relay, worked just fine but couldn't handle larger currents (1.5A) that it had handled last Summer. The voltage crashed under the larger load, dropping the relay used to connect the load, the battery voltage recovered, relay closed connecting the load again and the crash repeated at high frequency with an audible buzz). Suggest borrowing another likely good battery and install for test purposes.
Generally, with electrical problems:
1. Start with the basics and start at the beginning (in this case the lowside battery)
2. Always make a note of what you have tried with the results (it saves going round in circles.
3. Make no assumptions and always recheck someone elses work if the problem persists. Just because they said they tested something, doesn't mean that they did it correctly.
4. Take a logical approach and always start with checking the power source to the faulty item and work from there.
Apologies, but to repeat myself, thermocouples generate very small signal voltages and electronics used to measure thermocouples generally don't like to have the thermocouple wires grounded ESPECIALLY in a noisy vehicle environment where ground potentials shift dependant on where you measure and under what vehicle operation.
Did Autometer support ever get back to you? If so, what did you ask and what did they say?
Do you have a model number for the meter? Pics of the install location & thermocouple would help me understand your problem better.
Apologies for the lengthy post...
- Thread starter
- #36
Yes i took power fron the low side battery, the battery on the passenger side, the battery that has the neg to the frame. Otherwise i guess i'd had already blown the gauge.
My Mitsubishi Montreo, the day after i got the gauge installed for the first time, i try connecting the 12v+ of the gauge directly on the converter. I also parked my montero next to the BJ and using booser cable i plug the cable on the + and - and feed the gage with it. That test was good and i wasn't having any problem.
Since i installed the second thermocouple and it wasn't working i emailed them back and ask the question, that was thursday if i remember correctly, no response since them, i just email them back again.
Yes i know they have to match, and obviously that is what i did, but like i explained, when i wired the extension throught the firewall and under the dash, i installed the wire the wrong way. Due to size of the round terminal for hook up at each ends.
When i realise =tthe terminal wouldn't fit behind the gauge i cut the terminal off and crimped new one on the extension, if metal use in the terminal needs to be the same, that is probably my problem, i'll ask Autometer for a new extension, after i test hooking the gauge directly in the installed thermocouple and battery
That is what i'll do next, start with the basic and work my way to finish installation.
Will do
Sure i do this all day long
Not yet
Pyrometer link from Autometer
http://www.autometer.com/cat_gaugedetail.aspx?ref=search&gid=2797
Instructions;
http://www.autometer.com/img/lbl_instructionalDownloads.jpg
Now Autometer didn't send a new ceramic washer, obviously when i pulled the first thermocouple out, that thing went to dust. So i don't have it anymore. Also the instruction say drill 1/4", but thats the thermocouple diameter, so the first time, getting it in wasn't a loose fit!.
No mather how long i would have read it all!
Thanks a bunch! And see below for pictures
Yet more suggestions...
Thanks for the photos & info links, which I just read.
1. It is definitely a thermocouple being used and not an RTD sensor.
2. That's the good & bad news.
The good news: From the pictures, it would appear that there is really no way to really damage the thermocouple and short the wires to the sheath, so I assume they come like this from the factory. (The ones I use professionally are much more fragile and are easy to damage).
The bad news is that you have to find that bad ground connection. In the installation instructions it says use a good ground when connecting power to the meter. A "good" ground on a FJ/BJ4x can be challenging to find unless it is on the battery or next to the frame strap with a good low resistance connection.
3. The manual says that the extension must be used in its entire length to maintain calibration. Cutting off the ends to add new crimps shouldn't be an issue as long as the crimps are the same material. It does say that you shouldn't use solder and I agree. You shouldn't need to order a new extension yet...
4. The reason that your "other truck" test worked is because you effectively broke the ground loop that normally exists between sensor and meter when you use the BJ's battery (the Montera is effectively electrically floating).
So, what's next...
I'd check the engine and exhaust manifold grounding path to the low side battery. I make assumption that the engine is purposely and not incidentally grounded somehow but I'll have to go look at my vehicles to see. The aim of the game is to get a really low resistance conductive path from your exhaust manifold to the low side negative terminal. I think that this is your problem.
The conductive path can be measured either using the multimeter's resistance measurement capabilities with the truck off or via voltmeter measurement with the truck running. The problem is that most run-of-the-mill multimeters don't perform well in the sub 1 Ohm region. You are looking for a very low resistance of let's say <0.5 Ohm.
Fix this probable problem and I think your meter issue will vanish. It really doesn't take much electrical noise to disturb the thermocouple voltage of only a few 10's of millivolts.
Out of interest, before you disturb the current set-up, let me know what the voltmeter reading is between exhaust manifold at the thermocouple insertion point and the low side negative terminal at idle and revved up to where you are seeing the meter problem.
One other test you could do IF and only IF the above requested voltage reading between manifold and battery negative is under about 2.0 V and not fluctuating too badly (I'd hate to have you do something that MIGHT damage the meter), is to temporarily use the manifold ground as the meter ground. This will prevent a ground loop and very likely solve the issue (temporarily).
It is quite possible that the exhaust manifold is poorly grounded compared to the rest of the vehicle, with the use of an exhaust gasket, likely rusty or oxidised studs & bolts, anti-seize paste and generally with the exhaust attached to the frame with rubber vibration isolation mounts. A ground strap to the exhaust wouldn't hurt in this case if it solves the problem.
Both of my vehicles are out of commission at the moment so I can't give you a reference differential voltage reading to go by.
Please let me know how the above suggestions work out for you...(I'm all out of any other ideas at the moment)
Thanks for the photos & info links, which I just read.
1. It is definitely a thermocouple being used and not an RTD sensor.
2. That's the good & bad news.
The good news: From the pictures, it would appear that there is really no way to really damage the thermocouple and short the wires to the sheath, so I assume they come like this from the factory. (The ones I use professionally are much more fragile and are easy to damage).
The bad news is that you have to find that bad ground connection. In the installation instructions it says use a good ground when connecting power to the meter. A "good" ground on a FJ/BJ4x can be challenging to find unless it is on the battery or next to the frame strap with a good low resistance connection.
3. The manual says that the extension must be used in its entire length to maintain calibration. Cutting off the ends to add new crimps shouldn't be an issue as long as the crimps are the same material. It does say that you shouldn't use solder and I agree. You shouldn't need to order a new extension yet...
4. The reason that your "other truck" test worked is because you effectively broke the ground loop that normally exists between sensor and meter when you use the BJ's battery (the Montera is effectively electrically floating).
So, what's next...
I'd check the engine and exhaust manifold grounding path to the low side battery. I make assumption that the engine is purposely and not incidentally grounded somehow but I'll have to go look at my vehicles to see. The aim of the game is to get a really low resistance conductive path from your exhaust manifold to the low side negative terminal. I think that this is your problem.
The conductive path can be measured either using the multimeter's resistance measurement capabilities with the truck off or via voltmeter measurement with the truck running. The problem is that most run-of-the-mill multimeters don't perform well in the sub 1 Ohm region. You are looking for a very low resistance of let's say <0.5 Ohm.
Fix this probable problem and I think your meter issue will vanish. It really doesn't take much electrical noise to disturb the thermocouple voltage of only a few 10's of millivolts.
Out of interest, before you disturb the current set-up, let me know what the voltmeter reading is between exhaust manifold at the thermocouple insertion point and the low side negative terminal at idle and revved up to where you are seeing the meter problem.
One other test you could do IF and only IF the above requested voltage reading between manifold and battery negative is under about 2.0 V and not fluctuating too badly (I'd hate to have you do something that MIGHT damage the meter), is to temporarily use the manifold ground as the meter ground. This will prevent a ground loop and very likely solve the issue (temporarily).
It is quite possible that the exhaust manifold is poorly grounded compared to the rest of the vehicle, with the use of an exhaust gasket, likely rusty or oxidised studs & bolts, anti-seize paste and generally with the exhaust attached to the frame with rubber vibration isolation mounts. A ground strap to the exhaust wouldn't hurt in this case if it solves the problem.
Both of my vehicles are out of commission at the moment so I can't give you a reference differential voltage reading to go by.
Please let me know how the above suggestions work out for you...(I'm all out of any other ideas at the moment)
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I have not had the time to read this whole thread.. Anyway, it happened with my autometer pyrometers too. Replaced the gauge and coupler per warranty. It did nothing. I was sharing a ground with some other things, my guess was a stereo ground. Anyway I dedicated a ground to the pyro specifically and it was fine. I had the exact same symptoms. It also started happening about 6 months after I installed it, but oddly the brand new gauge did the same thing almost immediately. If you have not, give it a dedicated ground (to battery, or a single ground to body or chassis), and it will be fine..
