I've got a 2001 SC2. I have a rather challenging problem.
If you turn the ignition key on, and turn on headlights, the instrument panel illumination lights light up. As normal. All the gage dials are lit, as normal. Gas, odometer, etc. You can read the speedometer and tachometer.
As soon as youdepress the clutchto start themotor, the instrument panel illumination lights go off, and stays off.You can't see the speedometer or tach because the instrument panel illumination lights are off, but the fuel, odometer gage lights are on. Also warning lights, if any.
Checked the voltage going to the dimmer switch, and the voltage is there, 12 volts.And when I turn the headlights off, the voltage is 0. However, when I adjust the dimmer pot, there seems to be no change in voltage at all.
However, I have noticedthatmyinstrument lighting problem misbehaves the same whether I have the socket to the dimmer connected or disconnected. It looks like the dimmer may be bad.
Has anyone had problems with their dimmer? And why would the instrument panel light up when you initially start the motor, yet go off when the motor starts? What is the logic of the wiring? When you initially start up, does the wiring bypass the dimmer switch, thus illuminating the instrument panel,but then when the motor starts, it goes thru the nonfunctional dimmer switch and illumination goes off?


Any thoughts?


thks

Great -I get to talk to myself.


This is what I've learned so far. Because of all the hifi stuff my son added to the car, the positive battery post was lengthened to accomodate the extra connectors. For a long time, nothing happened. However, though the bolt was in there solid, there was some spacing between the flat circular terminal cable connectors - so it was probably causing all the "check engine" warnings, as well as probably causing deadly zaps - you know, like touching leads to battery terminals - zap. At one point it wouldn't even start. Remember - every time it says you are going to work on the car, it says "disconnect the battery". Now I know why.


These cars have mini-computers in them - like the BCM - the body control module. The diagnostic test said the BCM was shorted. My guess is that it got zapped. When I changed the fog light/dimmer module - the dimmer then began to work, which tells me I had zapped the dimmer.But I still had the same problem with the cluster lights at night. My mechanic said it looks like the instrument cluster illumination lights go thru the BCM also. Sounds crazy - but that would explain the illogic of the different situations - the brain is screwy.


The 2001 SC2runs good. I am still drivingmy 1992 Saturn SL1 with 235000 miles on it - so I know they can go for a long time if maintained reasonably well. So I guess I will have to cough up the dough for the new module - but lesson learned.


Disconnect the battery on your car before you do anything electrical.


Good luck. Hope this helps someone. Oh, and my mechanic has been right many, many times. And of course - he's an independent - not a franchise mechanic.

in the day my odometer shows numbers, but when you turn the lights on at night, theres no light to display the numbers.
Could the bulb be dead

Edited by: Zulu747