no gas gauge or temp gage

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swing69

fightin' socialism
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65 Barracuda - reawakening after 20+ yrs. of a driveway snooze. HERE is the LAST of the non functioning electrical issues.: No gas or temp gages working.

Grounded out both: no gage movement on either.... assuming both can be tested the same way...

SO...conventional wisdom would say its the voltage limiter. I removed it, cleaned the "legs". put 12v into leg. 1, and get ~ 6 volts out of the center leg. seems good, right?

SO: i cleaned all the traces and checked the leg socket to the gauge posts for continuity....all good.

SO: I figure both gauges are bad......but it would seem that that is unlikely.

SO: I removed the gage cluster......again......:

Question: with just the 2 posts; how can I check gauge functionality without burning them up?
TIA
 
Ground the wires going to the senders just for a short time- 5/6 seconds will tell you if the gauges are bad. If the needles peg all the way to high then the problem is elsewhere.
 
65 Barracuda - reawakening after 20+ yrs. of a driveway snooze. HERE is the LAST of the non functioning electrical issues.: No gas or temp gages working.

Grounded out both: no gage movement on either.... assuming both can be tested the same way...

SO...conventional wisdom would say its the voltage limiter. I removed it, cleaned the "legs". put 12v into leg. 1, and get ~ 6 volts out of the center leg. seems good, right?

SO: i cleaned all the traces and checked the leg socket to the gauge posts for continuity....all good.

SO: I figure both gauges are bad......but it would seem that that is unlikely.

SO: I removed the gage cluster......again......:

Question: with just the 2 posts; how can I check gauge functionality without burning them up?
TIA

If I am not mistaken your fuel and temp gauge run off a voltage regulator inside one of the gauges.
Google Mopar gauge voltage regulator.
On the later years the regulator is mounted on the back of the cluster.
 
I taped together a few AA batteries to test while the cluster was out. You can apply to the circuits and the gauges.
 
Well, with the cluster still installed you would read a bouncing voltage or 6 v average on the sender wire when disconnected. I'm sure there's a standard resistance, maybe someone knows the ohm value.
 
,66 should have the internal voltage regulator inside the fuel gauge. Lots of info here, use search bar to search.

When I opened up the fuel gauge I found my voltage regulator was toast (it's like a set of points that opens and closes to get something close to 6volts out). I added a 7805 digital regulator to replace the IVR. Here's a picture. I mounted it to a heatsink. All I had on hand was red wire so that's what I used, lol.

IMG_20141106_190827.jpg
 
,66 should have the internal voltage regulator inside the fuel gauge.

He has a 65 which might have the IVR incorporated within the fuel gauge; it’s been awhile since I looked at a 65 - can’t remember if it was that way or a separate IVR
 
He has a 65 which might have the IVR incorporated within the fuel gauge; it’s been awhile since I looked at a 65 - can’t remember if it was that way or a separate IVR

Oh crap, I missed that. I would think the 65 was also in the fuel gauge but I'm not certain. .

RTE sells a regulator ready to install. I almost went with one but wanted to build mine.

RTE limiter - rte
 
Its the external voltage regulator that fits into 3 slots on the back of the tracer board, with 3 legs. I think the later chryslers used the same VR tied a capacitor to them, also externally.

I cannot get either gage to spike by grounding the return side by the connector at the sensors OR by ground right at near the circular plug on the board. Makes no sense to me.

I'm thinking the 5v isn't making it to either gage, either at the tracer or circular connector point.

so I need to test the gage, alone, without any wiring....just post to post. Is there a resistance value?

Just found this: I guess I'll be doing this tomorrow!
 
Last edited:
Found the problem:
Took out the cluster, cleaned all the traces, replaced the bulbs, verified all the grounds, verified gages move with 6v applied (as in the above vid.), checked all the pins along the traces....all good. Turns out there was a corroded contact on one of the female sockets in the round pin connector.

Cleaned it all again.....powered it up....and all is well in the universe. ALL lights and other electrical devices work as they should.....for now, anyway.... :)
 
Great news! Its the little things. Have you thought about replacing the bulbs with LED while its out?
 
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