I have an early 4.2 that is experiencing trouble with the water temp gauge and the fuel level gauge. With respect to the fuel gauge...it appears to react fine for the initial startup of the engine. within a few minutes , the needle goes to the appropriate level then returns to "empty", then sporatically gives various level readings. I have changed the sending unit and get the same response. All connections appear to be tight. Temperture gauge acts much the same way. It appears to "climb" with the operating temp of the engine then it will suddenly return to the "coldest" temp status, then sporatically move around. This sending unit has been changed also.....is there a common thread between these gauges, lose connection? ...what is the proper test to determine if the gauges are in good working condition? any help would be appreciated.

Submitted by mfrank@westnet.com on Sun, 10/24/2004 - 23:10

This is an easy one. If you fold down the center panel of your dash, you will find a small box between the voltmeter and the oil pressure gauge. This is the instrument voltage regulator. It regulates the voltage to 10V for the fuel and temperature gauges only. Don't ask me why those two run on 10v, that's just the way it is. Check and clean all the connections to the IVR, and you should be fine. If the problem doesn't go away, replace it.