View Full Version : Low fuel light
05-05-2017, 01:54 PM
Just out of curiosity, I just had a fuel sending unit installed, put in a half tank of gas now it's down to just hitting the empty line, when does the light go on, I heard at 5 gallons left. I'm driving with a gas can in my trunk to play it safe.
05-05-2017, 04:48 PM
Did you ever see the low fuel warning light actually work. If not I would check the fuse first. If that's good check the relay. I believe it's located right around the fuse box. You may have to take the passenger kick panel off. If you find the relay you can check for voltage both from the fuse box and the sender unit at the plug. You can also jump the plug to see if the light works.
05-05-2017, 05:33 PM
The light does go on when I crank the motor and goes out once it starts, so I know the light works, now I will have to test the relay, keep you posted. Thanks!
05-06-2017, 01:06 PM
How exactly do I check the relay, I'm not good at electrics? Thanks.
05-06-2017, 04:14 PM
To test the relay you need to put 12V on two of the four terminals. The terminal by itself on the end goes to the light. That's your output. The middle terminal comes from the fuel sender. When your tank is low you should have voltage on the wire to activate the relay and light the light. If the light comes on when you start the car then the relay is at least partly working. The green/white wire at the plug comes from the sender unit so I would check there with a voltmeter or test light to see if you have voltage. You mention that you're not good at electronics. Unfortunately you picked the worst car to learn on. Flairbirds and especially the '66's are electrical nightmares. Fortunately all the schematics are available in the Technical Resource Library. They may look like Greek to a novice but they are very easy to follow once you figure out the wire colors.
05-06-2017, 05:54 PM
Thanks, fortunately most of the electronics are in good order on my car.
05-11-2017, 05:47 PM
Hey everyone, my low fuel light finally went on, the gauge reads way below the E mark, my question is should I pllt the sending unit out and bend the float, not sure I know how to do that, or should I pull the gauge itself and recalibrate that, that seems like more work to get the gauge out of the dash, I definetely don't know how to do that. Thanks!
05-11-2017, 05:49 PM
Oops sorry, I forgot I already had a thread started....brain fart!
05-12-2017, 10:08 PM
43 views and nobody has had this problem with their tbirds, I heard this was quite common?????:D
05-13-2017, 12:02 PM
You can adjust the sending unit. I believe the low fuel light goes on when there's just over three gallons left. You have to bend the float arm down slightly until the gauge registers about halfway between E and 1/4 full. It's trial and error to get it just right.
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