Pre-bus bar problem on 2h engine

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I'm not super when it comes to electrical issues. I have a 2h engine, 1982 (Oct.) HJ47. I wanted to check the glow plugs, so took them out and tested them, found one bad. Replaced it, put everything back together (bus bar, etc.). then out of curiosity, I tested the "bar" that the lead wire attaches to to see how any volts it's getting. It gets 12+v. Then I tested the "bar" that shares the bolt with the "bar" I just referred to and it didn't show any voltage; neither did the bus bar. So I took the two "bars" off the bolt to investigate the connection. I saw that the one bar that the feed wire connects to is broken (no full circle of metal to go around the bolt. Not sure how that would have happened (I inherited a lot of issues from the PO). It wasn't particularly rusty at all, so didn't brake off from rust I don't think. Anyway, I cleaned everything and reassembled it the same way it was. Now, when I have the key "On" I do get voltage to the other bar and to the bus bar, BUT I also get a little bit of smoke and burn smell that comes up from the connection of those two "bars" around the bolt (see pic). It's on the side where the metal is missing on the "ring connector"? In the photo, if you look closely, you can see the broken ring I'm talking about. Why would that cause burning or is it something else? I assume it didn't smoke/burn before but maybe it stops and I never see it when I start the rig? Thanks, guys.

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it’s ‘arcing’, which means the voltage is jumping from one side to the other; melting the metal.

post a couple more picks of what it looks like cleaned up,
 
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It's not much different cleaned up--just cleaner looking metal but the main problem of the missing piece of the metal bar isn't going to change. I'll post a couple when I can. Is it the missing metal that doesn't then have contact with the second bar that has its ring connection on it the problem, then? If so, is that metal bar a special kind of metal or can I just solder any piece of steel onto it?
 
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more pics to figure out what you/PO have going on

.... if your buss bar is cooked from lack of an isolater
source a new buss bar and don’t forget to add to cart an new isolater
 

fjwagon

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It's looks like a catastrophic failure of a component shorting out....is my guess and this was the weakest link. Something happened to make it draw more current than normal. Loose hardware my have caused too. Wrong glow plug possibly. Also not sure if it should have 12v at bus bar. I say this because glow plugs use around 8v to operate but 100% sure. I have an older diesel engine. Sorry not much help. Also not sure what type of glow plugs you are using but mine normally use about 10 amp each. I would verify you have the correct glow plugs for your engine.

I definitely post this thread in the diesel section.
 
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It's looks like a catastrophic failure of a component shorting out....is my guess and this was the weakest link. Something happened to make it draw more current than normal. Loose hardware my have caused too. Wrong glow plug possibly. Also not sure if it should have 12v at bus bar. I say this because glow plugs use around 8v to operate but sure. I have an older diesel engine. Sorry not much help. Also not sure what type of glow plugs you are using but mine normally use about 10 amp each. I would verify you have the correct glow plugs for your engine.

I definitely post this thread in the diesel section.
Thanks for the contribution. I should mention that BEFORE I took things apart and tested the glow plugs, I didn't have a problem with the start procedure. The problem of the current sensor metal part being partly melted became evident only when I took it all apart. And that's also when the bit of smoke started, so either I exacerbated a problem just enough to make the problem more evident by the smoke or it was waiting to happen. I don't know what the voltage of the existing plugs is and can't read anything on them, but I probably could try cleaning them up more to see if I can make out any voltage inset on the plug. I don't know if I have 12v at the bus bar. I have voltage and it read the same as on the connecting bar to the GPs and the same on the current sensor bar that goes from the resistors to the second metal bar that goes to the plugs. That was 2.48 volts or so, but that's probably not representative because on the same current sensor bar that I get that reading, I also get a 12v reading if I move the multimeter needle around on it. I didn't move it around on the bus bar and the other metal bar because I was afraid the smoking piece might mean more problems if I left the key on longer, so shut it off. What complicates it more is the PO added a momentary button, which normally means the 6v superglow system stopped working and this was a by-pass. It appears to be wired to the glowplug relay.
 
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Okay, so I took everything apart again and took out two of the glow plugs to find they are 6v plugs, which means I should be operating off the original superglow system, which makes me wonder why a momentary button was installed and why I detected 12v coming from the resistors to the current sensor bar. What is supposed to dumb the voltage down to 6 volts if it's not at the resistors? Sure wish I could have my own personal know-everything assistant next to me. :)
 

fjwagon

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I would say that sounds right on the 6 volt reading. Stuff breaks and replacement parts are sometimes hard to procure. So thing get by passed.

And you have an assistant, the search function up above. Like tell my son, " go ask your friend, Google...."

The damaged bus bar has to be replaced. The end of the bar may have been damaged due too much current that junction. Something caused it to get too hot that it oxidized and that started the messed you are seeing. So if it's a toyota glow plug, they generate about 10 amps.....times 6. A loose connection or a crack on the end can alsocause it . Imagine having 12 gauge wire and 70 % of the stands are broke. It would still pass a continuity test but it would probably fail a load test. Clean off the oxidation and make sure you get a solid connect. They do make glow plug that uses less current, (i think 8 amps) not much but it adds up.
 
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I would say that sounds right on the 6 volt reading. Stuff breaks and replacement parts are sometimes hard to procure. So thing get by passed.

And you have an assistant, the search function up above. Like tell my son, " go ask your friend, Google...."

The damaged bus bar has to be replaced. The end of the bar may have been damaged due too much current that junction. Something caused it to get too hot that it oxidized and that started the messed you are seeing. So if it's a toyota glow plug, they generate about 10 amps.....times 6. A loose connection or a crack on the end can alsocause it . Imagine having 12 gauge wire and 70 % of the stands are broke. It would still pass a continuity test but it would probably fail a load test. Clean off the oxidation and make sure you get a solid connect. They do make glow plug that uses less current, (i think 8 amps) not much but it adds up.
Good info. So how do I know when to use amps as the criterion and not volts? If I am using 6v plugs, what does that have to do with amps? (serious question)
 

fjwagon

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I'm not engineer and I'm sure there are better qualified members that can explain it better. But I will do best to explain....We have a saying, volts don't kill you amps do. So imagine a slow flow of water in a river. It should be easy to maneuver. That would be equivalent to a low amperage circuit. A raging river would be considered high amperage circuit hence more dangerous to maneuver in. All that has changed is the rate of flow water. So rate of flow in voltage is amperage.
So when we monitor a circuit we mainly do it by amps via a circuit breaker. In our case 12v dc remains constant and sometime it's stepped down(resistor is one example) or up( coil)So every circuit is rated by how many amps it can operate safely. When you exceed it.....the circuit breaker will pop. If the circuit breaker is too high it will not blow and if that happens it will cause something else to blow. Sometimes a component will fail but not enough to blow the CB so if we talking about a house circuit and it fails, the house may burn. So in your case the bus bar exceeded it's load and cause it heat up causing it to oxidized the end of the bus bar and the terminal next to it. Usually something loose will will cause it generate heat, hence the fuse will pop. Sometimes a component( glow plug) may fail causing it to short out and then maybe later in the same chain of events cause the glow plug to go to an open state. So the the rusty terminal is the remnants of whatever failure happened. It will have to cleaned, sanded replated or replaced if you can find one so the circuit does not over heat and cause issues later. I hope this helps in answering your question.
 
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I'm not engineer and I'm sure there are better qualified members that can explain it better. But I will do best to explain....We have a saying, volts don't kill you amps do. So imagine a slow flow of water in a river. It should be easy to maneuver. That would be equivalent to a low amperage circuit. A raging river would be considered high amperage circuit hence more dangerous to maneuver in. All that has changed is the rate of flow water. So rate of flow in voltage is amperage.
So when we monitor a circuit we mainly do it by amps via a circuit breaker. In our case 12v dc remains constant and sometime it's stepped down(resistor is one example) or up( coil)So every circuit is rated by how many amps it can operate safely. When you exceed it.....the circuit breaker will pop. If the circuit breaker is too high it will not blow and if that happens it will cause something else to blow. Sometimes a component will fail but not enough to blow the CB so if we talking about a house circuit and it fails, the house may burn. So in your case the bus bar exceeded it's load and cause it heat up causing it to oxidized the end of the bus bar and the terminal next to it. Usually something loose will will cause it generate heat, hence the fuse will pop. Sometimes a component( glow plug) may fail causing it to short out and then maybe later in the same chain of events cause the glow plug to go to an open state. So the the rusty terminal is the remnants of whatever failure happened. It will have to cleaned, sanded replated or replaced if you can find one so the circuit does not over heat and cause issues later. I hope this helps in answering your question.
Yes, that's clear. Thanks. So a busbar can be 12v but with different amps. Is that right? And a loose connection could have caused the meltdown of the ring connector of that busbar in the picture? Why would too many amps be going through the busbar? Would that mean the resistors in the pic I'm attaching could be faulty? But if they're faulty and let too high amperage flow through, wouldn't they burn up all the 6v plugs I have? I typically have to leave the GPs about 30 seconds to heat up enough to start the engine in 40-50 degree weather. Thanks for any input.
So I just tested the voltage only (not sure how to test amps on the multimeter I inherited) and when I turn the key to "on," I get 12 volts on the resistors (in the first pic) and the bus bar coming from the resistors. (second and third pics) and also the glowplug relay A few seconds later (not sure how many--maybe 20?), they all three show around 4.5 volts. Another few seconds later (again, not sure how many went by), they all test at about 1.7v. What's going on? Any idea? Thank you.

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fjwagon

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There is so much going on not sure where to start. The starter, yes the starter has to be functioning 100%. Under normal circumstances on a diesel engine since it's a high compresing engine it needs turn fast enough especially when the glow plugs are in use. If not you will tax the glow plug circuit. Cycling a 2nd or third time may ruin or shortened the life of glow plug. They need cooling period. The problem with the starter bogging down initial start may be a sign you have failing starter. It sometimes leaves the owner thinking the battery is under charged or somehow there's bad connection.

Glow plugs: since these engines are used in different regions it can be confusing as to which glow plugs you should use. So many options. The recommendation is replace all when one fails especially If you don't know the history. Save the old ones for temporary backups. Mixing the old with new ones may not heat up the same rate sometimes causing the engine to sputter, blow white/blue smoke on start ups. Since old and sometimes abused glow plugs heat element can become brittle and break apart of in the head. If you decide to reuse them, ohm them out, inspect for cracks or carbon build up and may apply voltage and timed them to verify how fast they heat up. They all should be about the same time.
I have H engine, it's a dog but that is what I have to work with. It's a simple circuit. Basically once the the GP relay is energized, the GP controller comes at the same time as the glow plugs. Once the GP controller is hot orange the engine is ready to be started.
The 2h glow plug circuit is not that simple. When "super glow" circuit fails, a lot owners will simply bypass part of the circuit and use a timer instead. Cannot blame them for the simple fact that logistically parts are not easy to locate and many mechanics don't want to spend a lot of time learning and fix something that is rare especially when they can make more money working on what they are familiar with. It's definitely a nitch, gotta find right the mechanic and hopefully they will be in your area.
 
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fjwagon

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I believe you have what they call the Super Glow system. It's a two stage setup since it has two relays going to the same circuit. These relays should not come on at the same time or at least not in the beginning
if it does it should turn off after whatever conditions are met....if not it could cause some major issues.
That being Said, relays are known to stick in the open/close position even though they click does not mean they are working. I wonder why the resistors on the inlet manifold installed there . I'm not sure if these are like thermistors. If they are they will have resistance when cold and when it's hot they may be open or vise versa... I doubt this is true. But you have to check for that to get a better idea how this circuit works. Or if they may just be resistors that help create that voltage drop needed for the glow plugs to operate. The sensor strap may also acts a resistor. The temperature sensor going the timer also needs to be checked. Put it on water and heat it up. Verify the ohm readings start to climb in linear fashion as it heats up. Check the timer for cold solder joints or bad components. Reflow the solder if you find any. Just be careful not to overheat the components. They can easily be damaged. On another note verify you have good connections through the circuit. Remember these are old rigs. Once the engine reaches a certian temperature the timer will turn off and should never come on until you turn off the engine. Once you turn on the engine and the temperature threshold is met the timer will come on and the cycle starts all over agian. Like I mentioned when the Super Glow plug system fails most will bypass this circuit because it can damage your Glow plugs and you have no way of know it's happening. You could be driving and the system may come, etc. I highly recommend doing a search in diesel section.
 
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fjwagon

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I forgot to answer your question how to check current. With a multi meter, set it for the current option. Next you have to open the circuit and connect leads to complete the circuit and then activate the circuit. Miniature jumpers or leads with grippers will help. I don't think this is the best way to check it. If I were checking current on this circuit i would definitely use clampon meter. The make different size clamps and the vary in price.
 

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