Gauges

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Joel Chapman

Joel Chapman

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Mountain Home, ID/ Hughson, CA
So I’m having a interesting gauge issue in my 71 Dart. When I turn the key to run my aftermarket tach/stock temp/fuel gauge all turn on, but when I start the car and it’s run all three don’t work. Only thing I have done recently is change my power steering pump and fuel sending unit back to the stock one so it would read the tank better. I’ve grounded the sending unit and even gone back and cleaned up where the ground strap attaches to make sure it’s metal contact. Other than that this hasn’t been an issue. Sometimes the tach wouldn’t work, but I could just turn the car off and turn it right back on and it would be fine. Any suggestions on what my issue is? Or at least some where to start looking? I’m thinking it could be a ground for the instrument cluster but where is the ground for it? Only ground I know of in the car is the steering column. As always thank you for the help!
 
You have a service manual/ wiring diagram? Go to MyMopar and download them

Anything else doesn't work, like brake warning switch? (Try the parking brake?) Think about the path everything takes. The key at some point feeds power to the cluster PC board harness connector. It could be dirty/ loose, but the big issue is the pins on the board can corrode or work loose and loose connection to the PC board trace---leading to the instrument IVR connection

You have A ralley dash? (You said "all three"). If so the IVR is in the fuel gauge. That trace connects to a stud at the fuel gauge, that stud can lose connection to the trace. Loosen/ tighten the nut on the gauge stud. Could be the IVR. Again if it's in the fuel gauge, this is special, and you pretty much must replace it with an external one. "Probably" time to pull the cluster
 
I've had an issue where all my gauges are dead on startup and it would go away if I shut it down and turned it on again. I found that if I wiggled my key a little my dash would fire back up. I'm figuring something is loose around my ign cylinder but I haven't had time to investigate further than that. I would say start there because it only takes a few seconds and is free
 
Very little on these classics has a ground wire. Majority of it is chassis grounded. Same applies to instrument panels but... if the illumination works, its grounded. Brake warning and oil warning get their ground through those remote switches. It never hurts to add an actual ground wire to the instrument panel.
I dont know where you got switched 12 volts for the tach but it should come from accessory fuse/fuse box.
 
67Dart273 said:
You have a service manual/ wiring diagram? Go to MyMopar and download them

Anything else doesn't work, like brake warning switch? (Try the parking brake?) Think about the path everything takes. The key at some point feeds power to the cluster PC board harness connector. It could be dirty/ loose, but the big issue is the pins on the board can corrode or work loose and loose connection to the PC board trace---leading to the instrument IVR connection

You have A ralley dash? (You said "all three"). If so the IVR is in the fuel gauge. That trace connects to a stud at the fuel gauge, that stud can lose connection to the trace. Loosen/ tighten the nut on the gauge stud. Could be the IVR. Again if it's in the fuel gauge, this is special, and you pretty much must replace it with an external one. "Probably" time to pull the cluster
Click to expand...
Sorry I meant three as the after market tach and the stock temp and fuel gauge. I have just the regular rectangular cluster set up.
 
RedFish said:
Very little on these classics has a ground wire. Majority of it is chassis grounded. Same applies to instrument panels but... if the illumination works, its grounded. Brake warning and oil warning get their ground through those remote switches. It never hurts to add an actual ground wire to the instrument panel.
I dont know where you got switched 12 volts for the tach but it should come from accessory fuse/fuse box.
Click to expand...
I got the 12v from the fuse box for sure and I’m almost positive it’s from the accessory
 
67Dart273 said:
You have a service manual/ wiring diagram? Go to MyMopar and download them

Anything else doesn't work, like brake warning switch? (Try the parking brake?) Think about the path everything takes. The key at some point feeds power to the cluster PC board harness connector. It could be dirty/ loose, but the big issue is the pins on the board can corrode or work loose and loose connection to the PC board trace---leading to the instrument IVR connection

You have A ralley dash? (You said "all three"). If so the IVR is in the fuel gauge. That trace connects to a stud at the fuel gauge, that stud can lose connection to the trace. Loosen/ tighten the nut on the gauge stud. Could be the IVR. Again if it's in the fuel gauge, this is special, and you pretty much must replace it with an external one. "Probably" time to pull the cluster
Click to expand...
Also as far as I can tell everything else is working. The gauge for the battery all the cluster lights up when I turn the lights on. Haven’t tried to see if the brake light comes on yet and the I got rid of the oil pressure sender for a mechanical aftermarket gauge.
 
I Hope the wire for OEM oil lamp is isolated/insulated. Its 12 volts and not fused in many year models.
 
2506C9F6-B83A-42E0-B80A-F7C3DC79356B.jpeg
67Dart273 said:
You have a service manual/ wiring diagram? Go to MyMopar and download them

Anything else doesn't work, like brake warning switch? (Try the parking brake?) Think about the path everything takes. The key at some point feeds power to the cluster PC board harness connector. It could be dirty/ loose, but the big issue is the pins on the board can corrode or work loose and loose connection to the PC board trace---leading to the instrument IVR connection

You have A ralley dash? (You said "all three"). If so the IVR is in the fuel gauge. That trace connects to a stud at the fuel gauge, that stud can lose connection to the trace. Loosen/ tighten the nut on the gauge stud. Could be the IVR. Again if it's in the fuel gauge, this is special, and you pretty much must replace it with an external one. "Probably" time to pull the cluster
Click to expand...

Any chance I can solder these pins or is it time for a new board?
2506C9F6-B83A-42E0-B80A-F7C3DC79356B.jpeg
 
Joel Chapman said:
View attachment 1715861935
Any chance I can solder these pins or is it time for a new board?View attachment 1715861935
Click to expand...
If the pin isn't secured to the board, only soldered, next time the connector is removed the pin may go with it. Peeled the copper trace off the board.
Your picture shows example of repair with hardware. So long as the screws head doesn't touch metal behind the board, it works.
 
RedFish said:
If the pin isn't secured to the board, only soldered, next time the connector is removed the pin may go with it. Peeled the copper trace off the board.
Your picture shows example of repair with hardware. So long as the screws head doesn't touch metal behind the board, it works.
Click to expand...
Your right! Last night I didn’t even notice those two other bolts next to the pins. Well in my tired mind didn’t think they were anything important lol.
 
I pulled a pin out of the circular pin section on my Duster. I just ran a small screw through the other side to act as a pin and it's held for over a decade now with no issues.
 
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