when I turn on the headlight switch???

[P944GUY]

when I turn on the headlights, and fog lights-both on at the same time..... I notice that my engine temp needle kinda jumps up and shows it's running warmer than before I turned the lights on. I've replaced the engine temp sensor that goes to the instrument...the spade type connectors aren't corroded..and I repaced the headlight switch. I have replaced the "brushes" in the alternator and the battery is fine. I had the charging system checked and it's running to specs. I've checked the grounds--and cleaned.. under the dash next to a big block of wire connections. I've even had the instrument cluster out of the car and cleaned all the connector screws on the back--and yes, it did this before I took out the inst. cluster. Is there something else I need to inspect??


Any ideas?? Stumped in Phoenix

[Inspector7]

I installed another ground from the front of the engine to the left front ground point behind the headlight and the problem lessened.

The problem is that as the cars age the electrical system develops more resistance and a new ground wire will help. I have also replaced the wires that ground the battery to the chassis and added a ground directly from the engine to the battery and the hot wires that go from the battery to the starter and from the starter to the alt.

I have higher voltage at the battery, the volt meter shows higher when the engine is running, the headlights seem brighter and the instruments don't jump around ramdomly like they used to.

Hope that this helps

[rachwalj]

So you added a connection from the engine block to the ground bolt behind the driver's side headlight? This was NOT from the battery terminal, just from the engine to the headlight ground?

I need all the help I can get as I am still fighting my own electrical problem.

[UconnTim97]

I had a similar problem, and cleaning the grounds cleared it up.....

[lousailor]

Is there a voltage regulator that may be going bad? I've had similar symptoms in other cars.

[Inspector7]

I have since replaced the voltage regulator in the 951 and there was a small improvement in the performance of the gages. I now have about 1.2 more volts at the battery while the engine is running.

I was also getting sluggish starting and dim headlights but that has all gone away since the replacement of the voltage regulator.

There is a person on Rennlist that goes by the handle Iceshark that makes a wiring kit that will do everything that my home made wires do except that his wires look a whole lot better.