Power to Gas Gauge Float

[bluecuda]

Help!  My gas guage on my '73 Baracuda is stuck on EMPTY!  It appears that the float has never been taken disassembled or taken out of the gas tank. The ground appears to be in tact.  We've tried to use a different ground wire but the guage still didn't work.  Tested the power line with an electric continuity tester.  It appears that there is no power to the float.

 What am I overlooking?  Any help here is greatly appreciated.

[Plum6Pak]

You aren't suppose to have power to the float, that is the ground and depending on where the float is determines how much ground you have or in other words how many ohms resistance going to the gauge, if you ground the wire that hooks to the float, it should peg the fuel gauge to full, if your wires are all good, if you are getting voltage to the positive side of the gauge, I would say your gauge is bad.  :thumbs:

[Chryco Psycho]

the power goes through the guage & to the sender to ground so yes you should have power at the blue wire to the sender

[Plum6Pak]

Chryco is right as long as the wire that is being tested is dissconnected, it's the negative side of the gauge and the negative side of anything will show power if it isn't grounded. Hope you get it working!  :thumbs:

[Wrencher]

the power goes through the guage & to the sender to ground so yes you should have power at the blue wire to the sender

Measureable with a DVOM, not a test light.

[nivvy]

is the gas tank grounded to the car at all....i cant get my autometer fuel guage working either....all i have is a sender wire from the guage that goes to the tank and a ground coming from the guage also....but where does the ground from the guage go to??? and is there a gground wire from the tank to the frame???

8 Pack

[Wrencher]

After reading the Autometer instructions, I see why this is confusing.  Normally, the gauge is grounded in the dash area and the fuel tank is grounded somewhere in the rear of the car (fuel lines) and only the sender wire runs from the gauge to the sender.  But Autometer wants a continious ground wire run from the gauge all the way back to the tank along with the sender wire.  But they fail to mention that the tank MUST be grounded even if you run the extra ground wire from the gauge to the tank.

So to summarize:
1.  Make sure gauge I terminal is getting power
2.  Make sure gauge GND terminal is grounded (good ground on dash support would be fine)
3.  Make sure sender wire from gauge to sender had good continuity
4.  Make sure tank sender is grounded to body.
5.  Make sure all connections are clean and tight.

[GoodysGotaCuda]

Maybe i over read this part, but did you check for a float thats full of gas?.....

[nivvy]

so maybe grounding the guage under the dash and then off the same post run another ground wire  the whole way back to the tank and the ground the gas tank to the frame somewhere?

8 Pack