Light switch and fuel guage reading .

[Portuguy]

A small glitch when switching on lights ,with engine running the fuel guage reading jumps madly to full plus . Can this be sorted easily ? ( as far as i know the fuel tank doesnt fill up too !)
Any tips thanks Aidan

[Jimmy Cooper]

If the lights are turned off does the fuel gauge perform normally? If so then there is short from the lighting circuit to the positive side of the gauge when you switch the lights on.
Have you been working around that area (when looking at the battery cut-off switch etc)? Might have disturbed things.
I'd have a good look under the dash to see what's what. Might be very obvious when you do!

[Portuguy]

Yes , fuel guage works normally when light switches are in off position . Will check behind dash but not easy to access or see unless i can get into contorsionist positions with a torch etc . Several dial ilumination lights are not working and the speedo light goes on and off . Just niggly things but better to sort out .
Thanks Aidan

[Jimmy Cooper]

Ah yes, lying upside down with head in footwell is a bit nauseating but there's a h*ll of a lot more room without the propshaft tunnel as I had on my Caterham Se7en. Now that was tight!
I put a cushion in the footwell of my Lomax and it wasn't too bad at all.
If you have what appears to be other dodgy gauges then definitely look at the wiring behind them and sooner rather than later. A 12 volt battery stores a lot of energy and that is not funny when wiring looms short out and the previous owner didn't quite get the fuse links correct and then you have that 'orrible smell of melted plastic (and only that if you're lucky)!

Good luck!

[hutchii]

Aiden,
Sounds like an earth fault to me. Maybe some moisture has got to a contact that goes live when you switch the lights on.
Years ago I traveled home in the snow and to avoid the handbrake freezing on, decided to leave the car in gear as we lived on a hill. I kept my foot on the brake while I switched the ignition off. The engine continued to run! Took my foot of the brake pedal and the engine stopped. I then found that with my foot on the brake, with the ignition off, I could start the engine by just pressing the starter button!
I eventually traced the problem to moisture in the offside front indicator, (presumably melted snow) bridging between the live feed and the outer shell of the light.
Hope this helps
Ian

[Jimmy Cooper]

Ian.
That wasn't moisture you removed but the automatic anti stall, hill start device................................I'll get my coat.....