Looking for guidance in resolving my loss of gauge info after running out of gas. My working gas gauge falsely indicated 1/4 at the time my engine quit in the middle of traffic. I fortunately was able to drift to the side of the road and made several attempts to start it to no avail.
After Roadside Service came to the rescue with a gallon of gas, I was able to immediately start the car and drive home. After starting the car, I notice all of my digital info and analog tachometer and speedometer were inoperative. The only gauge working was the voltmeter! What's the source of power to the aforementioned gauges? What does the instrument panel function have to do with running out of gas?

 

I have no idea why it happened but I would check my fuses. I believe #10 is for instruments. Also #44 is instrument lights.

 

good idea to also disconnect the battery and clean the battery terminals,
and the ground strap attachment point

 

I checked the #10 fuse and it is good. The battery ground cable is new and the attachment point is a good clean ground. I'll check the #44 instrument light fuse tomorrow.

 

dont forget to disconnect the battery this will reset the system so it will relearn

 

I disconnected the battery for 10 minutes as recommended without a positive result. All the lights in the panel and the voltmeter still work. Any other suggestions?

 

Have you refilled the tank yet or is it still near empty? As it seems related to this and you already checked main grounds / fuses that is where I would start, maybe unplug the fuel sender at the tank and see if that has any impact. You can also ground the sensor wire which should make the needle move to max. maybe report back on that what that test does.

guide from Theo' site

"There are three wires at the fuel sender connection in the rear of the car. Look under the rear carpet, there is a shield and a plastic round cover. Once removed, you will see the 3 wire connector for the sender. The sender has a resistance of roughly 74 ohms to ground when the fuel level is empty and roughly 0-2 ohms to ground when the tank is full. To check your gauge, pull the connector off the sender, jump the ground wire (brown) to the violet striped wire. Turn on accessories with the key (you don't need to start the car). By jumping those wires, you are sending a close to 0 ohm signal to the gauge. It should read full."

 

Originally Posted by Mrmerlin View Post
dont forget to disconnect the battery this will reset the system so it will relearn
I got a 1991 and been having similar issue with my fuel gage reading false. I been having to recalibrate the gage.
Question : Will disconnecting the battery will make the reading on the gage false again?

 

It was fuse 24 that caused this in my 89. Try checking it. It also caused the LCDs to go nuts at the same time so...

As for the gas gauge giving a bad reading you may need to clean/replace the level sender or force the system to relearn.

 

On my 89S4 there are only two wires going to the sender, violet/ black and green/brown. It apparently came that way from the factory, as there are only two matching receptacle studs and everything operated normally before this problem. With the key in the accessory position, I jump wired the leads as suggested and there was no movement of the gas gauge. Checking the violet to ground, there was no indication of any power coming from that lead. The tank is full. Puzzled, I guess I'll just standby for more suggestions

 

Many years ago I ran out of gas when testing the digital readout on my 90S4. Filled the thing from the fuel I was carrying [just in case] and everything worked normal again. As to what caused your issue remains to be seen. If there is a link between running out of gas and then losing the dash info then a blown fuse would be the obvious starting point.

 

As mentioned in the previous replies, I checked the fuses that seem to be related to the instrument console, #10 gauges and #44 panel lights. Both were good.

 

Quite a mystery indeed- I hope you get to the bottom of it soon- maybe Alan can chime in with his electrical thoughts. Sometimes the leak path is not quite so obvious

 

have a read of this thread https://rennlist.com/forums/928-foru...t-cluster.html i think testing to ensure correct power and grounds are getting to the cluster would be next, but don't see how this could be related to running out of fuel.

 

You need to replace the fuse