Hey guys I'm struggling with an issue on my 70 GS with rally gauges. All my dash lights works, speedo and tach works but I don't know what's going on with my rally gauges. Fixed some grounds and my fuel gauge is working fine, my oil sender unit is bad so I don't know if my oil gauge works but I can't have working my temp gauge, already replaced the sending unit but it still don't works. Sometimes it works and it starts reading coolant temp but as soon as it reaches half gauge it stops working and it comes back to "cold" and sometimes after turn headlights on or crank engine it goes from half to cold. Already checked grounds and even have a wire directly from the battery negative to the dash housing but still don't works, my last try was to add a wire from the housing to the gauges circuit board but the issue isn't' gone What else can I try or what should I being chasing?
Not sure where you grounded from, but, The rally gauge pod has a ground strap that goes to the speedometer. I actually put a wire on there and grounded the pod to the dash ground. That solved my wonky gauge issues.
Yes I'm using a wiring diagram but I think is wired correctly and using meter to check continuity and voltages My strap is missing so I put a wire through the speedometer, tachometer and gauges housing, also used the same wire to ground directly to the speedo and gauges circuit board. This wire goes directly to the battery negative wire that I installed. Where you grounded that wire? also, how you installed it? maybe through the gauges housings?
Corosion or loose fuses to the dash circuit. Poor connection at the 2 plugs that plug into the printed circuit behind dash cluster, Grounds should be batery to block, block to frame, block to firewall, frame to firewall. Dash stuff grounds to firewall. Wiggle , Wiggle ,Wiggle test. Wiggle the dash cluster connections, headlights switch, main bulkhead to the fuse box thats the firewall connection . Nylon butt connectors .
Is this a factory equipped gauge cluster or was the car converted to factory gauges? So you ran a wire from the metal housing on the gauge cluster to ground? You can test the operation of the gauge itself by grounding the green wire on the manifold. When grounded, the gauge should read past hot. And with the green wire disconnected, the gauge should read past cold.
