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Anybody got any idea on what could be causing this.... Always happens when truck has not been warmed up...If I let it warm up for 20 minutes its fine but the problem is that when I just start and go, my temp guage and my oil pressure guage both go up a pretty good amount. When warmed up.. the temp guage is at the first little mark on the guage and the oile pressure is just about on the halfway mark....but when its cold and I just start and go, they both go up and slightly return to normal or close to normal. Now I was told that it could be the Instrument Cluster Voltage Regulator....... Is this true? Or is there something I am missing that I have not yet been told about? Any help would be great. Thanx.
I don't think it's anything to worry about. I wish I could have simple problems like that with my 77!! If it really concerns you, go get a triple gauge set (oil, water and volts) You can install one in about 1 hour on a bad day. Those dash gauges are junky anyway.
At first glance it doesn't sound like a problem to me. When cold the oil is thicker and it is normal for the oil pressure reading to be higher until the temp comes up and the oil thins out. The temp gauge could be that the coolant in the block is heating up until the thermostat opens and cold coolant is allowed into the block. When the engine has been running long enough all the coolant has equalized to the same temperature and the gauge settles into the point it will run at.
Unless you are having driveability problems, I wouldn't worry about it.
i agree that the oil pressure gauge will read on the high side till it warms up and the oil thins causing the pressure to drop. but i dont think the coolant gauge should go high at startup then drop. it should slowly raise and will probably go a little high till the thermostat opens as 76supercab2 suggested then it will drop to a normal running temp. if it is going up as soon as the truck is cranked then back down it seems like there is some kind of electrical fault in your system. i also agree that if the truck is running fine and you are ok with the gauge acting funny then dont worry. Eddie II
Oil Gauge is normal, the temp gauge could be a slightly sticking thermostat I have a 79 that I bought after it had sat for many many years and it would do that until I put a 180 deg thermostat in it
It may be an instrument panel voltage regulator that has lost it's ground. Remove the cluster, remove the voltage regulator and clean the surface of the flex circuit with a pencil eraser and some alcohol. Reinstall the regulator.
When the regulator has a bad ground the regulator supplies too high a voltage to the gages which causes them to read very high.