temp gauge problem
 

I have a 97 f-150 4.2. When the temp gauge starts to increase the amp and oil gauges top out. When it reaches full temp., the temp, amp and oil gauges bottom out. I replaced the sensor but that did not help the problem. Any clues on what the problem is.

RE: temp gauge problem
 

With electrical problems it's good to always start by cleaning battery cables and checking fuses/fusible links. Next I'd look for an antifreeze leak (antifreeze conducts electricity and shorts things out when splashed around - wash/wipe dirty wires under the hood). Next I'd check sensors and I'd look for a crossed wire or a problem in the dash cluster. Could also be a computer problem.

RE: temp gauge problem
 

Or if you have an electric fan - could be fan relay.

RE: temp gauge problem
 

Thanks for the info. when I get a chance I will try your suggestions.

RE: temp gauge problem
 

Do your lights get brighter when this happens? It could be a voltage regulator problem.

RE: temp gauge problem
 

That's sounds right. Voltage regulator affects a lot of electrical items in the basic accessory scheme of things. Starter circuitusually remains normal, etc. and electrical systems go crazy.