dead fuel gauge?

[miketyler]

After 3 weeks, I got a call from the body shop to tell me my fender was painted and ready to go. On the bright side, the metallic paint I provided them was a VERY close match and the car is all purple once again.

Pleasantly surprised I paid the man and hopped in the car and was prepared for the always tense drive home. I turned the key on and noticed no movement from the fuel gauge. Bodyshop guy swears they didnt do anything to the electrical and only moved the car around the shop. I stopped by the gas station and filled up to make sure I was good for the trip home.

Once I got home I grounded the sender line and still no movement. What I do notice is that the low fuel indicator is now pulsing very fast. Any ideas on this one? I didnt want to pull the guages if it was an obvious symptom of something else. The fuel tank and sender are both new. Any ideas?   

[MEK-Dangerfield]

Does your temp gauge, and oil pressure gauge(if you have a rally dash), look normal? If so, then I really have no other advice other than pulling the gauges out and taking a look. You verified that the problem is not the sending unit, so the gauge either isn't getting power, or it is dead. I would look into the voltage limiter for the gauges if the temp. , and oil pressure look funky too.


  Mike

[miketyler]

yes, they are ok. I know they all max out when there is no ground to the guages.

[MEK-Dangerfield]

Mike,

   I would have to say it's the guage then. Or maybe you can be lucky enough to of had one of the wires fall off of it. 


  Mike

[miketyler]

I will probably take it apart as soon as I get a replacement; but if it was just the gauge wouldnt my low fuel light be on steady?

[miketyler]

I fixed this today - I did test the tank sender as someone theorized that the float had sprung a leak and the sender was reading empty. The tanks showed to be sending a "full" signal at 6.6 ohms.

Next, I looked at the o/h console wiring diagram. Unlike the std fuel gauge, the fuel gauge with a low fuel circuit is powered by the relay. I checked the source going to the relay and it was getting 12V already. The 5V pole going to the gauge was dead. I touched a 12V lead to this 5v connector for a few seconds just long enough to see if I might get any needle sweep. Sure enough the needle climbed all the way to full and my low fuel light no longer pulses.

I cant be sure if it was the relay or fuel gauge that was stuck but all appears to be working now. I guess I'll know for sure if the needle doesnt drop with fuel consumption     

[MEK-Dangerfield]

It is possible for a relay to stick so maybe that's what happened here. 


  Mike