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oil and Temerature guage M38A1

Posted: Sat Jul 26, 2008 5:36 am
by Leo
Hi,
My oil pressure guage works intermitantly, and the Temp guage gives a flicker when ignition is switched on then doesn't register.
I have cleaned up the contacts on both senders without any change.
What are the most likely reasons for failure, would it be the guage, or the sensor, also can you change the sensors without draining the oil and water?
Thanks

Posted: Sat Jul 26, 2008 7:30 am
by Ryan_Miller
Hey,

Go to the downloads section (at the top or at the the left under navigation "downloads") and in the M38 electrical section look at the document on gauge trouble shooting and testing.

It could be your sending unit, wire continuity, guage, take a systematic approach.

The other way is to replace one part at a time - either a gauge or a sending unit, etc.

Posted: Sat Jul 26, 2008 8:48 am
by wesk
Keep in mind there are two flavors of oil pressure gages and senders. 60 PSI and 120PSI . the sender must be the correct one for the gage.

Guages

Posted: Sat Jul 26, 2008 10:28 am
by Leo
I'll go through them as said. I think the guages and the senders are original, so should be correct.
Thanks

Posted: Sat Jul 26, 2008 4:51 pm
by wesk
Less then 20% of the parts in most 50 year old jeeps are still original. They are labeled though. Before starting the troubleshooting sequence and just spinning your wheels clean up each sender and gage and get the numbers off them recorded.