Joined: Sat Jun 07 2008, 12:59AM
Location: Fort Lewis, Washington
Posts: 394
Ok so I have been driving my car for 2 years now with no fuel gauge...I just drive off of the trip odometer. I finally decided enough was enough so I bought a replacement sending unit and just installed it, but the fuel gauge still does not work. (I have at least 1/2 tank in the car, so thats not the problem). I decided to chase down the wiring going from the sending unit to the gauge, and when I got behind the driver's side kick panel I see where the blue wire goes into a little harness, comes out then procedes up and that is where the wire comes out and it is not connected to anything. It has a little plug on the end of it, but I cant see anything to plug it into. I removed the steering column cover and looked at the back of the fuel gauge. It appears to have a red connector with a wire leading to a condesor, and that is it. There is a stud on the back of the gauge to the right of the red connector, but nothing is attached to it. Can anyone tell me where this blue wire is supposed to plug into? Can I just splice some wire onto the end of it and run it to where it needs to go? I will include a picture of the blue wire/plug to see if that helps. I would really like to stop driving off of the trip odometer, as that gets old quick...
Joined: Sat Jun 07 2008, 12:59AM
Location: Fort Lewis, Washington
Posts: 394
ok so update on fuel gauge issue...I climbed back under the dash and pulled the relay from the back of the gauge, it looks good and the connectors are all clean, but I have no idea how to test one of those. To see if the gauge itself worked I ran a jumper wire from the unused stud to a key-on power source and the gauge then went to full (which the tank is definitely not full). I only left the wire on for a few seconds because I didnt want to burn out the gauge. I then ran the same jumper wire to the blue wire and got nothing. I then ran the jumper wire to the stud on the old sending unit and manipulated the float and still nothing. I am totally lost now! At least I know the needle moves....
Joined: Sun Feb 26 2006, 08:46PM
Location: Kingston,Ontario
Posts: 5622
The "relay" is the voltage limiter which powers the fuel guage. it reduces 12 volts down to 5 volts which what the guage runs on. When you jumped the wire,giving the guage the full 12 volts and resulting in a "FULL" reading. 1.double check the ground strap at the tank. 2.You can either replace the limiter with another or upgrade to an electronic limiter. The old style bi-metal limiters were not reliable to begin with. i am using the RTE limiter and it deleivers a solid signal and does not harm the guage. http://rt-eng.com/mediawiki/index.php/RTE_limiter hope this helps.
Joined: Sat Jun 07 2008, 12:59AM
Location: Fort Lewis, Washington
Posts: 394
Thanks for the link, I will definitely order one of those! The question still remains though, the blue wire that runs from the sending unit up to the front of the car is not connected to anything...where does it go?
Joined: Sat Jun 07 2008, 12:59AM
Location: Fort Lewis, Washington
Posts: 394
Ok so another update...I went out and checked the ground strap and it's solid, no corrosion or anything. I then was thinking about the voltage limiter, and in order for it to limit voltage, power has to be getting to it. I read on that link that the old mechanical limiters sometimes stick, so i pulled it out and gave it a few good taps with the handle of a screwdriver and put it back in. The blue wire that doesnt connect to anything I stripped some of the insulation off and ran a clip lead from the wire to the IGN contact in the fuse box. I then ran another clip lead from the plug on the end of the blue wire to the stud on the back of the gauge and VOILA! The gauge went right up to half tank and stopped. I repeated my expirement 3 more times to make sure it wasnt a fluke, and it stopped in the same place every time. Does this sound correct to anyone? If this is the way it is supposed to be I will permanently splice in the needed wiring.
Joined: Sun Feb 26 2006, 08:46PM
Location: Kingston,Ontario
Posts: 5622
Having a factory shop manual for your car is invaluable information and I strongly suggest geeting one--or even a CD version of it from E bay. It will show the wiring and where the blue wire goes,and you will discover what's missing??? at the guage.. Each year,make,and model may have different wire schematics and i am not 100% sure of your car since it may be different than mine.
Joined: Sat Jun 07 2008, 12:59AM
Location: Fort Lewis, Washington
Posts: 394
I do in fact have the FSM, however it is in my garage which is a 2 hour drive from here. When I got back from Afghanistan I forgot to grab it when I picked up the car.