Thoughts on this Gauge Issue

[1969VADart]

While I am pretty certain my IVR burned up, I am less convinced on the gauges (but I am still going to pick up a replacement for each anyway). When I start the car the needle on the fuel gauge still moves; it just pegs all the way to the right like in the picture. The temp gauge needle collapsed like in this picture nearly out of sight and does not move on startup. Do you think that maybe just the temp gauge is burned up? Is it possible that the temp gauge is not burned up at all? I have a new limiter so I am going to go ahead and replace that anyway. But I would appreciate your thoughts about these gauges.

 

[TrailBeast]

While I am pretty certain my IVR burned up, I am less convinced on the gauges (but I am still going to pick up a replacement for each anyway). When I start the car the needle on the fuel gauge still moves; it just pegs all the way to the right like in the picture. The temp gauge needle collapsed like in this picture nearly out of sight and does not move on startup. Do you think that maybe just the temp gauge is burned up? Is it possible that the temp gauge is not burned up at all? I have a new limiter so I am going to go ahead and replace that anyway. But I would appreciate your thoughts about these gauges.

What do they do when you disconnect your temp sender wire on the motor and disconnect the sender wire from the tank?
(This effectively removes the ground for each gauge) and they should both read normal like they are when the key isn't on.

 

[67Dart273]

You could easily and likely screwed up both of them. This would be a GREAT time to rebuild the cluster, in other words yank it out of there and inspect and fix any problems. These have a habit of developing multiple problems

In my own 67 there were several:

The IVR was bad

The IVR SOCKET was bad.......the spring contacts were not making connection with the board traces

Several of the harness connector pins were loose or broken. In my case I eliminated the factory connector, soldered pigtails to the traces, and installed a pair of Molex connectors

The nuts holding the gauge studs were corroded. Loosen/ tighten them two-three times, consider replacing with "real" nuts

The board traces around the socket contacts were grimy, and the socket contacts got bent outwards for better contact. At least one bulb was blown

YOU SHOULD ADD a ground pigtail. Solder a wire to a ground point (or screw) and run it to the dash frame or column support

Here is a good thread on cluster PC board cluster repair

Printed circuit pins repair

As an example from above, here's a magnificent repair of the IVR socket:

 

[RedFish]

We can see the temp gauge is screwed. Whether a short in that gauge is effecting the limiter and fuel gauge or not is anyone guess. It is possible.

 

[1969VADart]

Yeah, I'm probably just going to pull the cluster and replace both gauges and the limiter. Something definitely burned up because we could smell it in the car when it happened.

 

[RedFish]

The contact pins on the circuit boards are a common point of failure in this example but a short circuit anywhere can cause a gauge to fry. They can't handle zero resistance for very long especially when the OEM mechanical limiter would send higher voltage through them. When you go at it, check that purple wire from temp sender all the way to the gauge. Otherwise you might fry another. Good luck with it.

 

[TrailBeast]

Something definitely burned up because we could smell it in the car when it happened.

Well that could have been mentioned earlier.
I have some working later gauges I pulled out of an early 70's dart cluster, but sad to say they were the round style instead of square.
They will find someone that needs them some day.

 

[1969VADart]

Well that could have been mentioned earlier.
I have some working later gauges I pulled out of an early 70's dart cluster, but sad to say they were the round style instead of square.
They will find someone that needs them some day.

Yeah, I guess I could have mentioned the burning smell. Guess I didn't think about it in the context of the question. I already found a couple of new gauges to install and I already had one of the new solid state limiters. May try to tackle this in the next week or so. I hate to have to pull the cluster out because the wiring is so finicky and it is a PIA to remove. But this is my penance for not doing it when I knew it needed to be done before.

The contact pins on the circuit boards are a common point of failure in this example but a short circuit anywhere can cause a gauge to fry. They can't handle zero resistance for very long especially when the OEM mechanical limiter would send higher voltage through them. When you go at it, check that purple wire from temp sender all the way to the gauge. Otherwise you might fry another. Good luck with it.

Thanks for the suggestion. I will definitely check the wire and the pins.

 

[66jim]

If you disconnect the fuel sender wire on the tank and measure from that point(on the wire side) to chassis
ground should read 5v this will check status of regulator, same on coolant temp sender. I would use individual
regulators for temp, oil, and fuel Radio Shack 7805 rated I think at 1amp, they are only about 2 bucks, possibly mount them remotely off the circuit board to be changed easily? I have used them many times integrated into the circuit board seem very reliable.

 

[Dartswinger70]

You don't need gauges, although I suppose a fuel gauge would be nice, but not needed unless you are flying an airplane...

 

[1969VADart]

Turns out my fuel gauge is still working, though not optimally. This leads me to believe that only my temp gauge actually burned up at this point.

You don't need gauges, although I suppose a fuel gauge would be nice, but not needed unless you are flying an airplane...

Well I did drive my car yesterday despite this problem, so there is some truth to your point.