Dash Gauge Problems

[opelgtboy70]

I have had a problem with my oil pressure gauge sometimes working and sometimes not working. I put a new sending unit and it still does the same thing. I figured it was a ground problem. Now, my tach is acting funny. When Im driving down the road its fine, but when I push on the brakes it jumps real high and then stays there until I let off the brake. Anyone else have this problem? Do you guys thinks its also ground related?

Karl
70 GT

[GTJIM]

Sounds more like a short out in the tail light wiring system somewhere.
Check out the brake light wiring system with an electrical meter - my GT had all the rear wiring melted on to the fuel tank ... braking was interesting!

[namba209]

I do believe you've got two separate problems. First, all the instrument panel ground wires are connected to the backside of the speedo with the main ground wire attached to one of the two fuse panel attaching studs. The oil pressure gauge problem could be nothing more than a loose spade lug either at the gauge or the speedo or a loose wire at the oil pressure transmitter, under the exhaust manifold. The tach problem sounds like a short in the wiring somewhere behind the fuse panel. Trace the wires from the brake switch, and the green wire from the coil, or look for worn insulation where the wires are close to the brake pedal. There's no easy way to diagnose these problems, just a visual inspection is the best you can do. HTH.

[kwilford]

Originally Posted by opelgtboy70 I posted this under electrical but it never showed up in the new post section.

Yes it did. This thread is the merged result..