MustangGTJunkie

I gotta 94 gt 5.0ho ohv. Its my dd and the temp gauge starting maxing out and then the oil pressure gauge did the same thing but it never actually started running hot but i replaced the thermostat amd the radiator and that wasnt it. So does anybody know what is? I was told it was probably a grounding issue. What does that mean ? Im new to this.

imp

Two gauges acting up at the same time suggests something wrong with other than the gauges themselves, rather a poor ground connection causing incorrect response. Give me a bit of time to check my wiring diagrams to try to direct you in an appropriate direction. I, too, drive a '94 GT. Try to get back tomorrow. imp

MustangGTJunkie

Cool that would help out alot. The electrical stuff just isnt my specialty ha

imp

If it is caused by a bad ground connection, affecting Temp. and Oil Pressure gauges, those both are grounded externally of the instrument cluster. Unfortunately, the wiring diagrams do not show physically WHERE this ground connection is located. My guess is it's behind the instrument panel, possibly grounded to the sheet metal frame of the dashboard. It will be close to the instrument cluster, and behind or beside it. Getting to that location would likely be easiest by removing the cluster and bringing it outward towards the steering wheel. The grounded wire will be colored BLACK with a WHITE STRIPE, and have a lug on the end where it is screwed to the body structure. FWIW, the conductor number is 397, in case you find someone with more detailed wiring location information.


Good luck! imp

wbrockstar

Im not sure on the 94-95 models,but the secondary ground on the 86-93 Mustangs is located between the driver cylinder head (rear) and the firewall.Its a flat braided ground strap.This is the ground for the interior/exterior lights,ac clutch,alternator and the gauges.A sign of a bad ground at this location is a temp gauge increase once you turn things on like the ac,blower motor,headlights.If your ground strap is the original,it needs to be replaced,but for trouble shooting purposes,make sure its tight and corrosion free.Your problem is most likely this ground,but to check the gauges and wiring,remove the sender wire for each gauge and ground the wire to a clean spot on the engine block.The gauges should peg to full.If they do,that usually indicates the gauge and sender wire are good,which leaves the ground wire or sender as the possible cause.

imp

Good Help! imp

wbrockstar

Apparently the 94-95 has a ground from the neg battery post to the driver side timing cover and another one from the driver side motor mount to the driver side framerail.