Fuel Gauge Gone Barmy

[Adrian]

hope someone can help with this one.

having problems with wiring.

 

ignition on, then fuel gauge reads normally.

ignition off... fuel gauge stays at level it was when ignition turned off.

turn lights on and fuel gauge goes straight to the top.

if ignition and lights are on it stays at full, turn lights off and it drops to normal reading.... if igntion and lights turned off at same time, gauge shows full!

 

have disconnected the wire for the gauge at rear of cluster and it still shows full when lights turned on.

 

have also noticed that revs drop momentairily on tach when lights turned on ...but dont drop in actual fact

 

have checked all wiring and cant see any apparent cross wiring...everything works a ok

 

any ideas would be welcome... mind you this is cheaper than filling tank with gas!! :gdit: :gdit:

[Guest Petemate]

Panel earth?

Then again, some modern fuel gauges stay where they were when ign tirned off, e.g. my Metro, my old Sierra inst pack fuel gauge, a few Escorts (can't remember which ones). The Capri one VERY slowly climbs up to the reading but goes down again with ign off. But the probs you are experiencing with the other bits on the inst pack leads me to think the panel earth is a bit suspect.

FWIW

Pete

[Guest elwe]

I would guess its an earth problem or an internal short.

 

Have you got an instrument cluster or seperate gauges? If you have seperates I would think its a bad earth. If you have a cluster I might be more inclined to think there is an internal short from the illumination circuit.

[Guest chris brown]

It must be a short on the pcb at the back of the cluster between the panel lights and the fuel gauge try removing the panel light bulbs as it may be around one of the bulb holders that the problem may be.

[Adrian]

i have sierra cluster.

will try taking all lights out and see if that helps...will look at earth as well...

take it this is the joy of building!!!

[nicko]

Hi I had exactly the same problem, cured by earthing the instrument panel!! Can't remember which wires to connect, but usually brown on the sierra loom, and black on the VG loom.

Hope this helps.

 

Nicko

[Guest chris brown]

take it this is the joy of building

Just one of 1000's

[Adrian]

managed to sort it.... terminal 2 on the rear of the cluster on mine is earth and not temp gauge as per the wiring diagram, that is term 7!!!

anyway, fuel gauge now reads the correct amount, only thing is it doesnt go to zero when ignition turned off...will settle for knowing when its empty.

[Guest chris brown]

only thing is it doesnt go to zero when ignition turned off

It shouldn’t it should read the same when off as when last switched on even if you have put more fuel in.

[Adrian]

at least something has gone right this last week.

thanks