Help diagnosis this problem

saab
900

#1

I have a 1995 Saab and lately my warning lights, alert light, the brake light and the gas light have been coming on from time to time, when this happens all of the gages drop to zero, the gas gage, oil gage, temp and tack, as well as the speedometer. The car continues to run just fine. After a few seconds the lights go out and all the gages return to normal. Tonight the lights came on and the gages droped and this continued for several minutes then they flashed very rapidly on and off for a full 2 or 3 minutes and then returned to normal. The car continues to operate just fine. Does any one know what could be causing this?


#2

You have a bad ground from your instrument panel.


#3

If it keeps on happening, there is one device that controls all those things if they are digital. Tne engine control module. If you can’t solve the problem within a few weeks, maybe changing that will help. Both Sears and Wal-Mart are selling code readers for around $100, in case you want to go as crazy as me.


#4

A code reader isn’t going to do anything to help solve an intermittent electrical issue with your gauges. Also your ECM has nothing to do with an intermittent electrical issue with your gauges.


#5

I would start the hunt by checking the power to the instrument cluster. It sounds like the power to it may be the problem. If you have a 900 model check the power on fuse 18 and see if that changes when the trouble occurs. If it does then the ignition switch may be the trouble.


#6

Thank you so much. I am not handy with automobiles at all. I hope to get my sons’ to help me with this. Where is the ground wire?


#7

Turn the ignition switch ON. One person observes the instrument panel, as another person gets under the dash, and moves and wriggles all the wires under there. When a wire(s) is moved, and dash lights/gauges flicker, you have found the suspect wire(s).


#8

I’ve had several Saabs, an '85, '87, and '00. At least one of them (can’t remember which or perhaps all) had a “blackout” mode for the instrument panel. It is part of the “born from jets” concept. Pilots sometimes need total darkness for night visability and this feature was incorporated into Saab cars. As I recall all the instrument lights went out and the gauges were disabled and a warning light would come on if you needed fuel, or the temp went up or oil pressure dropped etc.

I don’t recall how you would turn this blackout feature on or off, but I did use it on long highway trips at night. Pehaps this system is on your '95 and is contributing to your problem(s) in some way.


#9

It is not on the panel that has the black out mode/ That is the area where it notifies you of a particular problem. This problem is my dash board light and gages. All the instrument gages drop to zero and black out except for the warnign light, the gas light and the brake light.


#10

Telling someone they have a “bad ground” is code for I don’t know.

I say, I don’t know.


#11

Well that was my best shot in the dark, sorry it didn’t help.