recently cleaned the temp send unit and afterwards my guage started pegging all the way to the right. car is not overheating. put in new sending unit and no change. anyone have any ideas about why this would happen. I know that if voltage limiter goes bad both temp and gas gauge will do this together but is it possible that limiter is bad and only one guage is affected. any thoughts would be appreciated....vic

If your gauge is pegging, the sender wire is grounding. Perhaps when you removed the wire from the sender, a weak spot in the insulation finally rubbed through, and it's now grounding out on the head or another metal surface. Better fix it fast -- this will cook your temp gauge in a hurry!

dan...I would agree except when I disconnect the wire from the sending unit the guage goes completely back to left (no reading). I assume it woudn't do that if grounded somewhere....vic

Your pulling the wire off the sender could be enough to move the grounded part away from ground. Or, the socket itself could be faulty. Or, you could have gotten two faulty senders. Have you measured the resistance across the sender (one ohmmeter lead on the terminal, the other on the base)?

It would be highly unusual (impossible, as far as I know) for a "temp gauge pegs, fuel gauge doesn't" problem to be in the voltage limiter.

I have a similar problem, except my gauge starts out reading normal, then slooooowly creeps up until it's pegged. The engine is not overheating. Bad sender?

Shiftless, yeah, yours sounds like a bad sender.

dan, not sure I know how to test ohms correctly but with my meter set on 20K I get a reading of 17. what should I get. also I played with the wire with it disconnected and somone watching the guage and no movement. right now I'm thinking the easiest thing to do is to hook up a new temp gauge separate from the old one. If I don't figure this out soon. I don't drive car that much but would like to get this resolved. just stubborn I guess.

The fuel gauge may not peg along with the temp gauge if the fuel tank is low on fuel. If you fill the fuel tank then the gauge may peg along with the temp gauge.

You can check if the instrument cluster voltage regulator is working by connecting a voltmeter to the wire that goes to the sender. You shold see a pulsing voltage. If you do not have a volt meter, you can use a low wattage tiny 12 volt bulb instead. If you use a bigger lightbulb like for the tail lamp or brake lamp you could damage the voltage regulator.