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Old 06-29-2008, 11:10 AM   #1
acl
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I know, not again

Temp gauge will still not work. have grounded cab, grounded wire to sending unit and it pegged gauge (i think that means gauge is good) changed sending unit 3 timesdid continuity test and still show no ground at gauge. fuel, oil, and battery gauge work. can i run a ground from somewhere straight to the temp gauge? this has been on going for months. I have tried every response you guys have giving i am not getting anywhere. Any more help would be greatly appreciated. Gary
A new thought, how does the ground get from the fuse block to the circuit board? where should I look to see if this is happening?

Last edited by acl; 06-30-2008 at 02:17 PM. Reason: addition
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Old 06-29-2008, 12:10 PM   #2
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Re: I know, not again

did you put thread tape on the sensor? It's a pipe fitting, which doesn't need the tape. The tape may be causing the sensor to nto ground.
The green wire going to the sensor IS the ground. If you ground the guage anywhere else, then the guage will be pegged.
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Old 06-29-2008, 12:31 PM   #3
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Re: I know, not again

X2 on that.. .
i had that issue cause i was not paying attention
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Old 06-29-2008, 12:32 PM   #4
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Re: I know, not again

Quote:
Originally Posted by Longhorn Man View Post
did you put thread tape on the sensor? It's a pipe fitting, which doesn't need the tape. The tape may be causing the sensor to nto ground.
The green wire going to the sensor IS the ground. If you ground the guage anywhere else, then the guage will be pegged.
orig yes but have since removed per your earlier instructions, but still nothing thanks l
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Old 06-29-2008, 12:42 PM   #5
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Re: I know, not again

Mr. D. Mitchell, good pic of gauge. I have no wires going to gauge at all, thoght that was covered by circuit board?Also, have whie ceramic piece but no yellow or silver trail between top and bottom post. Is that the prob.
Longhorn Man, If the green wire from senser to firewall is also a ground, how does the gauge get a temp? I think i get stupider every question I ask. Thanks you 2 for helping, most greatful. Gary
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Old 06-29-2008, 01:43 PM   #6
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Re: I know, not again

It shows the temp by the amount of resistance there is to getting that ground. The gauge itself is getting 12volts on one side, but it is insulated from ground. Essentially, the sender gives it a progressively better ground. That is why the gauge goes to full hot if you touch the wire directly to ground.

The fuel level sendor in the tank works the same way. It has a rheostat connected to the float that measures the resistance.

Last edited by LONGHAIR; 06-29-2008 at 01:46 PM.
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Old 06-29-2008, 01:45 PM   #7
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Re: I know, not again

exactly. Variable ground so-to-speak.
And don't feel like you are looking stupid. This is a step above the basic stuff.
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Old 06-29-2008, 02:06 PM   #8
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Re: I know, not again

Is it possible you are getting the wrong sender for the gauge?Has the gauge been changed/possible wrong year combo?
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Old 06-29-2008, 03:09 PM   #9
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Re: I know, not again

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Is it possible you are getting the wrong sender for the gauge?Has the gauge been changed/possible wrong year combo?
I think its right i made sure i ask for a gauge and not a light sender.
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Old 06-29-2008, 04:49 PM   #10
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Re: I know, not again

utilising the picture it gives you the basic circuit info you need. it is not an exact picture of your circuit it is a diagram of the circuit lay out, it's telling you all the info you NEED to get started...
the rest can be figured out with a little thinking and maby your chiltoms diagrams... or the autozone website diagrams also..

but here's what you do.. check teh resistance through your guage using the + side through the - side it should read the same as that picture..
if your guage "rings out" correctly and your sensor itself is "new" then you have a damaged or grounded wire somewhere it depends on how the guage is working...
now i also have an extra guage sitting here i can send to you (for cost of shipping) that you can have the needle is broken off but it's a good guage..
so... also.... hmm tryign to think of a reference do you have a MULTIMETER?
or ohmmeter?
if not the cheap ones at autobone are ok.. and fairly easy to use, you dont have to dump 300 bucks (like some of us) to get the pretty ones ....
...
just start from the beginning dude.. think out the circuit.. and trouble shoot.. start with the simple Q's...
1) WHAT PARTS ARE NEW AND REPLACED?
2) IS MY GAUGE WORKING? (CHECK RESISTANCE)
3) IS MY CIRCUIT CARD WORKING PROPERLY (continuitiythrough circuit? is the connection on the circuit itself clean and in useable condition?)
4) IS MY WIRING CORRECT? (ie damaged wiring burtnt wiring missing wiring? dirty cnnections or improperly placed coorls light can)
5) CHECK FROM THE GUAGE TO THE FRAME OF TRUCK FOR CONTINUITY (CHECK FOR GOOD GROUNDING without this your circuit is incomplete and will not work no matter what until you fix that)

ALSO what position are you using for your sensor? is it the one in the top of the intake manifold or is it the one on the exhaust side? (generally people use the one by your sparkplugs and exhaust side, i use the top one i dont see the difference) but in using the intake manifold one you run the risk of an improper grounding between your sensor and your block...

i hope i wasnt too long winded good luck
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Last edited by dammitmitchell; 06-29-2008 at 04:52 PM.
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Old 06-30-2008, 06:51 AM   #11
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Re: I know, not again

Quote:
Originally Posted by dammitmitchell View Post
utilising the picture it gives you the basic circuit info you need. it is not an exact picture of your circuit it is a diagram of the circuit lay out, it's telling you all the info you NEED to get started...
the rest can be figured out with a little thinking and maby your chiltoms diagrams... or the autozone website diagrams also..

but here's what you do.. check teh resistance through your guage using the + side through the - side it should read the same as that picture..
if your guage "rings out" correctly and your sensor itself is "new" then you have a damaged or grounded wire somewhere it depends on how the guage is working...
now i also have an extra guage sitting here i can send to you (for cost of shipping) that you can have the needle is broken off but it's a good guage..
so... also.... hmm tryign to think of a reference do you have a MULTIMETER?
or ohmmeter?
if not the cheap ones at autobone are ok.. and fairly easy to use, you dont have to dump 300 bucks (like some of us) to get the pretty ones ....
...
just start from the beginning dude.. think out the circuit.. and trouble shoot.. start with the simple Q's...
1) WHAT PARTS ARE NEW AND REPLACED?
2) IS MY GAUGE WORKING? (CHECK RESISTANCE)
3) IS MY CIRCUIT CARD WORKING PROPERLY (continuitiythrough circuit? is the connection on the circuit itself clean and in useable condition?)
4) IS MY WIRING CORRECT? (ie damaged wiring burtnt wiring missing wiring? dirty cnnections or improperly placed coorls light can)
5) CHECK FROM THE GUAGE TO THE FRAME OF TRUCK FOR CONTINUITY (CHECK FOR GOOD GROUNDING without this your circuit is incomplete and will not work no matter what until you fix that)

ALSO what position are you using for your sensor? is it the one in the top of the intake manifold or is it the one on the exhaust side? (generally people use the one by your sparkplugs and exhaust side, i use the top one i dont see the difference) but in using the intake manifold one you run the risk of an improper grounding between your sensor and your block...

i hope i wasnt too long winded good luck
You make it sound so simple. thanks so much. i will re-ask you a question, does my ceramic piece on the gauge need the metal strip between top and bottom post? or the yellow piece? thanks
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Old 06-30-2008, 07:20 AM   #12
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Re: I know, not again

This comment is just from my experience....

The wire from my temp sensor to the gauge on my truck had a break in the insulation that was allowing the wire to ground to the engine block, and intermittently. I thought the needle on my guage was going to break off, because it would go to full hot reading from another point on the guage....like the arm on a metronome. New wiring harness fixed my problem. I had other issues, too. All is good on mine. Good luck on yours. This website rocks with folks who know their stuff.
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Old 06-30-2008, 02:14 PM   #13
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Re: I know, not again

Quote:
Originally Posted by acl View Post
Temp gauge will still not work. have grounded cab, grounded wire to sending unit and it pegged gauge (i think that means gauge is good) changed sending unit 3 timesdid continuity test and still show no ground at gauge. fuel, oil, and battery gauge work. can i run a ground from somewhere straight to the temp gauge? this has been on going for months. I have tried every response you guys have giving i am not getting anywhere. Any more help would be greatly appreciated. Gary
A new thought, how does the ground get from the fuse block to the circuit board and where should I look.
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Old 06-30-2008, 09:53 PM   #14
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Re: I know, not again

ok look in the picture i wrote top o n the back of the gauge so you would know which way indicates up just to totally elimane any confusion =-) those screws plug straight into your plastic "pod" or whaterver it's called that holds all your gauges and your circuit board U should have three pinch clamps that those bolts go into...
(just to make sure you are not missing a single peice anywhere)

[IMG]<a href="http://s295.photobucket.com/albums/mm131/dammitmitchell/?action=view&current=DSC00463.jpg" target="_blank"><img src="http://i295.photobucket.com/albums/mm131/dammitmitchell/DSC00463.jpg" border="0" alt="Photobucket"></a>[/IMG]
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Old 06-30-2008, 09:59 PM   #15
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Re: I know, not again

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Old 06-30-2008, 10:17 PM   #16
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Re: I know, not again

Try this disconnect the wire going to the sender. Run a wire from the sender on the motor to the guage where the sender wire would normally go, gauge should work. This will tell you if the circuit board or the wiring harness has a problem in the ground circuit.
If that works trace the circuit board to the harness plug, touch the wire at that point, guage should work again. That will tell you if the circuit board is ok. If ok trace that wire in the harness.
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Old 06-30-2008, 10:26 PM   #17
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Re: I know, not again

Quote:
Originally Posted by acl View Post
A new thought, how does the ground get from the fuse block to the circuit board and where should I look.
No grounds go through the fuse block and fire wall plug. The ground connection for the printed circuit is made by a wire that clips to the dash. The wire goes straight from this point to the plug that connects to the printed circuit on the cluster. A couple of the screws that mount the printed circuit to the rear metal part of the cluster also electrically connect that metal part to ground, so make sure no screws are missing.

You must an intermittant in the green wire somewhere.
Take the green wire that plugs onto the sender and ground it, preferably to the body of the sender, and if the gauge pegs hot, wiggle the wire around to see if it changes. It has a connection at the firewall plug, and one where it plugs into the cluster. The wire itself could be bad somewhere. IF it won't peg to hot by grounding to the sender body, take the sender out and clean the threads in the hole so it makes good contact. I put teflon tape on my sender and have never had trouble. (been there 3+ yrs now)
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Old 06-30-2008, 10:41 PM   #18
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Re: I know, not again

No Teflon
BAD BAD!!!!he he he
serioulsy it will interrupt the signal path of the circuit
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