I have an issue with my reserve fuel light and over heat light. It seems that both gauges work correctly, that is the needle part of the guage, however when I first turn on the car, and it goes through the process of a dash illumination check neither one of those bulbs illuminate. The rest of my dash warning lights do. I have checked the bulbs and they are fine I even bought another instrument cluster and it does the same thing. I have repeatedly run down the gas to the point that it is well in the reserve area just to see if the light will illuminate which it does not. Does anyone have any suggestions on what the fix is. Could it be an issue with the DME? The car is an 87

 

Well I haven't driven my 951 in sometime now, but I really have to run down the needle for the gas and then it lights up. Almost all german gas gauges do that. What I mean by that is that they don't tell you really how much gas you have. From what I seen they are always 1/4 to 1/8 off. In my bmw the gas gauge is full for a long time and then it starts dropping down like I have a big V8 in there lol. How much do you fill up when you go down on the gauge?

 

I could understand that if... the lights did not come on during the process of the dash illumination check, but neither one of them does (water or gasoline). When I fill up it is usually a half tank, but I dont see how that would make much of a difference. I have done all the "quick fixes" I can think of. ie cleaning the contacts, replacing the bulbs, checking diodes. To the point of replacing the whole instrument cluster,with no luck.

 

Both of those "idiot lights" are turned on by a simple switch.

For the temp gage the switch is in the temp sensor. The reserve light switch is part of the fuel level sensor.

Both lights will energize when their respective switches close and send a ground to the insturment cluster.

I just checked my 951, and neither light comes on when I turn on the ignition. The only lights I get are for the parking brake and low oil pressure.

To test these lights all you need to do is turn the ignition on and ground the wires.

 

you should be seeing the alt lite too, when the key is on.

if the alt lite doesn't come on at that time, how will you know when/if ithe alt fails?

 

the low fuel light worked in my first N/a and I dont think it works in the 951, but IT WONT come on when the key is on.

The car has to be low on gas for the little low fuel light to be on.

As for the high temp light, I never knew we had one of those....

When the alternator fails, or the alt belt is gone, the alternator light and the big ! light should both light up.

 

What I mean by that is did you run the car down on gas and then filled up like 18-19 gallons? Then the light should have been on. I recall running mine down on the gas gauge where the needle was on empty cause the light doesn't turn on as most of our gas gauges don't read right. They are always off by 1/4 to 1/8 on the gauge but the light comes on when you have only 2.2 gallons left and not what the gauge says.

 

Mine used to work and now it does not seem to. It doesn't bother me, but I don't run the car down on gas all the way, so not sure if it still does or not.