Gloucestershire AR Posted August 23, 2022 Share Posted August 23, 2022 After some repairs on the car that necessitated removing the tank, the fuel gauge is not working. The needle comes up off its stop but reads empty even though the tank is/was full. I've since driven 90 miles and no real change.The needle also from time to time now twitches but never goes up to its correct reading.Is this likely to be a faulty sender or faulty (VDO - it's a 1998 car) gauge? If the sender had been rewired incorrectly (the wires switched) what would be the effect then?Thanks all! Link to comment Share on other sites More sharing options...
SM25T Posted August 23, 2022 Share Posted August 23, 2022 Take the boot floor up and look at the cables. The earth on mine is fitted under the head of one of the securing screws. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 23, 2022 Member Share Posted August 23, 2022 The fuel indication works by the sender showing a variable resistance to earth.You can start to localise the fault by finding the Green/Black connection on the gauge: that's the one that is connected to the sender. Disconnect that wire and with the ignition (ON) connect that terminal to a good earth. What does the gauge do?...But with your previous question about pipe fittings at the tank I suspect that that is where the problem lies. Once you know that the gauge is working find the sender and tell us what colour wires you can see.Jonathan Link to comment Share on other sites More sharing options...
Gloucestershire AR Posted August 23, 2022 Author Share Posted August 23, 2022 Helpfully (!) both wires appear to be black...Is the earth the one to the centre of the sender, or the one attached to one of the bolts holding the sender in?What would happen if I swapped them over?Puzzled... Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 23, 2022 Member Share Posted August 23, 2022 Swapping the sender-to-gauge and sender-to earth shouldn't affect anything. But I'd want to be sure that I was looking at the right wires... are the fuel pump wires in the same area?Can you trace either of those two Black wires to a connector with a Green/Black wire?The one to a bolt is presumably the sender-to-earth.Jonathan Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 23, 2022 Member Share Posted August 23, 2022 If you're using the gauge rather than a multimeter as a diagnostic tool I recommend that quick check above to be sure that the gauge is working OK.Jonathan Link to comment Share on other sites More sharing options...
Gloucestershire AR Posted August 23, 2022 Author Share Posted August 23, 2022 Good news! Switched the wires at the sender and everything now works OK.Thanks both for the suggestions - I really don't understand electrics!Thanks again. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 23, 2022 Member Share Posted August 23, 2022 Well done.Jonathan Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now