Gauge issues

[Z3_GoCar]

I've got two gauges that are giving me issues, my oil pressure gauge and my Tach. Both are Autometer Ultralite. I suspect the sender for the oil pressure gauge is going due to vibrations as it's reading really low.

As for the Tach, I checked the signal wire for continuity and it's whole. Anyone get theirs fixed from Autometer? Or is it disposable, and I should just get another?

 

[joeg]

I'd suspect wires or senders before the instrument.

I have the same issue with an electric fuel pressure gauge; but I tried both an Autometer and SW.

Autometer is quality stuff.

 

[Chip42]

verify the connections first.

for autometer 1 wire oil pressure you should have ~240 ohms through the sender to ground at 0psi. 100psi is ~33 ohms - so go to radio shack and get some resistors. start with a chain, place that between the gauge signal line and ground, and remove resistors and recheck. you should see rising pressure readings from 0-100 using resistance values between 240-33 ohms.

for the tach, it's more difficult. check the wiring, put a scope on it if you can and look for a square wave of the appropriate f.