Multimeter question! (1 Viewer)

[chicago]

When looking for "CONTINUITY" in ohms on the multimeter, is any value recieved considered continuity?I was trying to test my main EFI relay in effort to find the warm start problem, and the manual I have said to hook the battery (12 volt) to the 2 and 4 terminals, and test the 1 and 3 terminal with an ohm meter...If there is continuity, the relay is fine...I came up with a value of 2.8. Does this mean that its working?when I hooked power to it, it clicked...I regretably do not know ANYTHING about electronics and/ or diagnosis of electronics in ANY capacity, so Im trying to learn by the seat of my pants...I tried calling my dad, but he pulled the ole "father routeine" on me and told me everything I needed to know except...what I needed to know!Thanks,Chicago

 

[450 DUDE]

The clicking is a good sign.
2.8 is kinda high, I dont know what else its going through.
if you are checking termnials ant the same " board" it should be like .003

When you put the probes together what reading do you get?
Did you clean the relay termnials?

HTH

ken

 

[chicago]

The clicking is a good sign.
2.8 is kinda high, I dont know what else its going through.
if you are checking termnials ant the same " board" it should be like .003

When you put the probes together what reading do you get?
Did you clean the relay termnials?

HTH

ken

Hey Ken,
I just bought the multimeter today, and have never used one before...
Per the instructions, I touched the 2 probes together, and I got 0.00.
When I was screwing around getting the reading on the relay, the switch on the ohm meter was set at 200...
I donno what an ohm is, what an ohm does or what the readings mean, but I DO KNOW, that doing the initial relay test without hooking power to it, the 2 and 4 terminals were supposed to have continuity, and the 1 and 3 were NOT, and THAT checked out as it was supposed to...
The manual doesnt give a value for what "continuity" is, and Im assuming one is supposed to know that prior to working on a rig?
FU*KING stupid Haynes manual!
The reading what I got...(I think was 2.8 or .28, something like that) made me think the value was really LOW, and may not be passing sufficient current, and thus, indicating a weak current through the relay?
What is continuity defined as in terms of ohms?

Keith

 

[450 DUDE]

OK,
A OHM is a unit of resistance IE If your wanting a signial to go through, Resistance (ohms)=bad
Put your meter on a lower (limit) # if you have one like 10 or 20.
How expensive and hard to replace is the relay?
Idealy the reading you get when you touch the 2 probes together is what you want (no resistance)
You have continuity but something is not conducting 100% (dirt , corrosion , poor connection, funk, David hasselhof)

ken

 

[rusty_tlc]

When looking for "CONTINUITY" in ohms on the multimeter, is any value recieved considered continuity?I was trying to test my main EFI relay in effort to find the warm start problem, and the manual I have said to hook the battery (12 volt) to the 2 and 4 terminals, and test the 1 and 3 terminal with an ohm meter...If there is continuity, the relay is fine...I came up with a value of 2.8. Does this mean that its working?when I hooked power to it, it clicked...I regretably do not know ANYTHING about electronics and/ or diagnosis of electronics in ANY capacity, so Im trying to learn by the seat of my pants...I tried calling my dad, but he pulled the ole "father routeine" on me and told me everything I needed to know except...what I needed to know!Thanks,Chicago

You have my cell #, use it.

An ohm is the unit of resistance to the flow of current. The voltage drop across a resistance is found by the formula: V=IR where V=volts, I=current, and R=resistance.

Your meter will have serveral resistance ranges, higher resistances are expressed in a form of short hand. A value of 2,000 ohms (or 2x10^3) is expressed as 2K, 2,000,000 ohms (or 2X10^6) is 2M and so on. Unless we know what range the meter was set to it is impossiable to tell what the actual resistance you measured was.

Every relay has a certain amount of contact resistance, this is normal. The question is yours within spec? I'd post up on the 60 board and see if anybody has a FSM with the factory spec. contact resistance.

 

[chicago]

You have my cell #, use it.

An ohm is the unit of resistance to the flow of current. The voltage drop across a resistance is found by the formula: V=IR where V=volts, I=current, and R=resistance.

Your meter will have serveral resistance ranges, higher resistances are expressed in a form of short hand. A value of 2,000 ohms (or 2x10^3) is expressed as 2K, 2,000,000 ohms (or 2X10^6) is 2M and so on. Unless we know what range the meter was set to it is impossiable to tell what the actual resistance you measured was.

Every relay has a certain amount of contact resistance, this is normal. The question is yours within spec? I'd post up on the 60 board and see if anybody has a FSM with the factory spec. contact resistance.

Hey Dan,
I think I mentioned above that the ohm switch was set at 200 on the meter.
The manual didnt specify a value, only wether or not there was continuity. If there was continuity when the relay was energized from battery power, then the relay was fine, if there was no continuity, then it instructed replacing the relay...
Should there be a definitive value to say YES, this is good, or NO, this is bad.

Thank GOD there are people who undertand electronics!

I appreciate the input!

Ill post up on the 60s forum!
Im gonna have to get with you on how this meter stuff works as I have NO CLUE!

As for the cell number, I dont wanna bother you with my lame-o rookie questions too often, especially when youre at work!

Keith

 

[rusty_tlc]

Hey Dan,
I think I mentioned above that the ohm switch was set at 200 on the meter.
The manual didnt specify a value, only wether or not there was continuity. If there was continuity when the relay was energized from battery power, then the relay was fine, if there was no continuity, then it instructed replacing the relay...
Should there be a definitive value to say YES, this is good, or NO, this is bad.

Thank GOD there are people who undertand electronics!

I appreciate the input!

Ill post up on the 60s forum!
Im gonna have to get with you on how this meter stuff works as I have NO CLUE!

As for the cell number, I dont wanna bother you with my lame-o rookie questions too often, especially when youre at work!

Keith

And thank God there are people who understand all that icky gooey stuff inside me.


I missed the 200 part.
If you zeroed out the test leads the contact resistance is 2.8 ohms.
That sounds a tad high, but I don't know what the normal contact resistance is specified at.

Continuity just means that there is an electrical connection. Even a straight piece of wire has some resistance, so nailing down continuity to an exact number is kind of hard.

Every relay has some contact resistance. If the relay becomes pitted from arcing, or dirty the resistance will increase. Usually this isn't enough to affect operation of the controlled device. Relays typically fail either because the contacts weld closed or the coil goes open which prevents the relay from operating.* That is probably why the Haynes book is written they way it is.



*Alert boring stuff to follow! A relay is a switch which is operated by and electromagnet, remember wrapping wire around a nail and hooking it to a battery to make a magnet? A relay works the same way. Relays come in two main flavors; NO - Normaly Open and NC - Normaly Closed. The electromagnet is used to pull a spring which closes or opens the switch when current is applied. When current is removed the switch returns to its normal state.

Don't worry about calling me, if I'm busy I'll just tell you I can't talk or not answer.

 

[chicago]

And thank God there are people who understand all that icky gooey stuff inside me.


I missed the 200 part.
If you zeroed out the test leads the contact resistance is 2.8 ohms.
That sounds a tad high, but I don't know what the normal contact resistance is specified at.

Continuity just means that there is an electrical connection. Even a straight piece of wire has some resistance, so nailing down continuity to an exact number is kind of hard.

Every relay has some contact resistance. If the relay becomes pitted from arcing, or dirty the resistance will increase. Usually this isn't enough to affect operation of the controlled device. Relays typically fail either because the contacts weld closed or the coil goes open which prevents the relay from operating.* That is probably why the Haynes book is written they way it is.



*Alert boring stuff to follow! A relay is a switch which is operated by and electromagnet, remember wrapping wire around a nail and hooking it to a battery to make a magnet? A relay works the same way. Relays come in two main flavors; NO - Normaly Open and NC - Normaly Closed. The electromagnet is used to pull a spring which closes or opens the switch when current is applied. When current is removed the switch returns to its normal state.

Don't worry about calling me, if I'm busy I'll just tell you I can't talk or not answer.

Thanks Dan,
Everyone has a Niche in life I suppose...Blood and Gutz has ALWAYS been my thing!
Thanks for the info above, and I do sort of understand it.
So, in order to really be able to ascertain wether or not the relay is functioning properly, I need to know the true working value of a good unit, correct?
I suspect that it is...I was really hoping that it wasnt, and that was my problem...I could hear it opening and shutting when energized via the battery, but Ill post up on the 60s section as youperscribed.

Keith