#1  
Old 06-26-2021, 09:52 PM
larrygroskopf larrygroskopf is offline
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Default Gas gauge reads full all the time

1979 Trans Am with a 1980-81 rally gauges and wire loom. I know 1980-81 was year they had the computer. The. Gas is a separate gauge. When I bought the car the gauge shows full all the time. When turn key on or start up it moves further . I lowered the tank to see if there was a ground wire on the send unit because I couldn’t see without lower tank. There is a ground is good as the rear tail lites uses the same ground .I had removed all the gas as was a year old. Put in 5 gallons gas does same thing. The sending unit is new. Is it possible it’s wrong sending unit? Reason being the inlet tube is in the opposite direction towards the back. So whoever did this ran rubber hose from the new line near tank around back and back up to meet the inlet. Wondering if sending units have different Ohms values and it’s not compatible with the gauge?

  #2  
Old 06-27-2021, 09:37 AM
Aus78Formula Aus78Formula is offline
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When you say it reads full, us the needle right over past the full mark, off the dial? That's a sign the sender isn't earthed.

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Old 06-27-2021, 01:31 PM
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highway star highway star is offline
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It does seem to be the wrong sending unit, being clocked 180 out. Replaced the unit in my '78 last fall & it has the ground wire attached & it bolts to the rear panel.
I don't know what year changes were made but I'd change your sending unit.

  #4  
Old 07-01-2021, 05:44 PM
autobahn autobahn is offline
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Did the previous owner install the fuel level sender? , it could be the previous owner didn't set the float up correctly,tho I'm inclined to go with the grounding

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  #5  
Old 07-02-2021, 09:33 AM
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Skip Fix Skip Fix is offline
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I've replaced the on in my 79 Camaro and 81 TA and on Camaro vs Firebird outlet is on different sides but pickup points the same way.

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