Fuel/Temp Gauge Accurate w/Lights On...??

[jerkyboy]

So my fuel and temperature gauges only work properly when the lights are on, regardless whether it's the parking or headlights but after awhile, both gauges go all the way to the max readings. When the lights aren't on, neither gauge reads accurately. Another weird thing is that when the lights are on, the right blinker light on the dash does not light up at all, but it works fine when the lights are off. Any suggestions?

 

[67Dart273]

Your cluster likely has grounding issues. There were several problems with my 67......

1......Several of the connector pins were loose, or even broke off. I elected to solder pigtail wires to the board traces, and connected them with a pair of Molex connectors instead of the originals

2......My IVR was bad, but even the SOCKET connections were bad. Solder across from the PC board traces to the contact fingers

3.....Two or more of the gauge studs/ nuts were not making contact with the PC board. Loosen/ tighten the nuts a few times to 'scrub' the connecton. Better yet replace the sheet metal nuts with "real" ones

4....GROUND.......the gauge cluster LISTEN UP!! This is likely your problem..........only grounds through the mounting screws. Solder/ bolt a pigtail wire to a common ground point, and screw that to the dash frame or column support

There's some tutorials around here on sprucing up the cluster board............Here's one now

Printed circuit pins repair

 

[67Dart273]

The black wire is added ground

The blue/ white is switched ignition voltage

You can see where I soldered across the board to the contacts of the IVR

Molex connectors replace the damaged pins The ammeter wires are small because I converted it to a voltmeter

 

[RedFish]

Some models have metal straps holding the wire harness up above the inst' panel. A few owners/members have removed their panel to find wire casing chaffed through and shorted to ground and/or together there. Every model type has its own issues.
Download the factory service manual, remove inst' panel. Good luck

 

[jerkyboy]

Thanks guys, the prior owner had the gauge cluster completely redone so hopefully it's a grounding issue. I'll add an additional ground as suggested. Appreciate the speedy responses.