Fuel Gauge Reads Full all the time
06-04-2020, 12:11 PM
#1
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Car: Firebird
Engine: 383
Transmission: 700R4, lots of Mods
Fuel Gauge Reads Full all the time
Greetings,
Does anybody know some troubleshooting short cuts / tips / links / diagrams, etc. to find out why my fuel gauge is reading full all the time. 1989 Firebird with stock tank and sending unit. Any and all information will be greatly appreciated.
Ciao~
BH
Does anybody know some troubleshooting short cuts / tips / links / diagrams, etc. to find out why my fuel gauge is reading full all the time. 1989 Firebird with stock tank and sending unit. Any and all information will be greatly appreciated.
Ciao~
BH
06-04-2020, 02:21 PM
#2
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Re: Fuel Gauge Reads Full all the time
In general, GM fuel senders measure 0-ohms when the tank is empty and 90-ohms when full.
You can measure this resistance at the fuel tank connector to see if it's the gauge or the sender. Doing it this way requires you to measure the resistance with the tank partially empty.
Or you can perform the test per the attachment (Chevy-Pontiac should be the same for both).
You can measure this resistance at the fuel tank connector to see if it's the gauge or the sender. Doing it this way requires you to measure the resistance with the tank partially empty.
Or you can perform the test per the attachment (Chevy-Pontiac should be the same for both).
Last edited by paulo57509; 06-04-2020 at 02:24 PM. Reason: Add gauge schematic
06-04-2020, 05:27 PM
#3
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Car: Firebird
Engine: 383
Transmission: 700R4, lots of Mods
Re: Fuel Gauge Reads Full all the time
Thank you for the information, let me ask you this question:
Before I ask, I have not read the Service Manual PDF's that you posted.
If I remove the connector for the fuel sender and pump (located just above the read diff) should the fuel gauge read empty?
Ok I am bit confused, how does the pink wire get to the dash. Is C208 located behind the back seat and is some how connected to connector C313 which is above the diff? I dont see any wires leaving the tank going to dash.
Thank you for your time.
BH
Thanks
BH
Before I ask, I have not read the Service Manual PDF's that you posted.
If I remove the connector for the fuel sender and pump (located just above the read diff) should the fuel gauge read empty?
Ok I am bit confused, how does the pink wire get to the dash. Is C208 located behind the back seat and is some how connected to connector C313 which is above the diff? I dont see any wires leaving the tank going to dash.
Thank you for your time.
BH
Thanks
BH
Last edited by bluegoose; 06-04-2020 at 05:44 PM. Reason: adding question about pink wire and connector C208
06-04-2020, 08:28 PM
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Car: Yes
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Axle/Gears: Behind me somewhere
Re: Fuel Gauge Reads Full all the time
Unplug = full
Short to ground = empty
See my signature
Short to ground = empty
See my signature
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