fuel gauge not working

[elmo makaroy]

hi , i have searched but cannot seem to find any answers

i have a 1982 Aircooled t25 with a cu engine, my fuel gauge doesnt work at all and i really need to fix it as im constantly worrying about running out of fuel,

im not sure how the fuel gauges work and wondered if anyone might have an idea how i would go about fixing it???

thanks

[BOXY]

The fuel level sensor is in the top of the petrol tank. Have a look at the link below to get an idea of how to get at it. The wire from it leads to a four pin connector behind the dash and then to the gauge.

https://club8090.co.uk/wiki/Fu ... nk_removal

[elmo makaroy]

great,

does any1 have a picture of the four pin connector behind the dash, i want to check this first as my dash panels have been removed for quite some time and i am thinking maybe it has come loose or been disconnected,

thanks

[BOXY]

Sorry no photo, but looking in the Haynes, I think the connector is fixed to the back of the speedo / clock assembly. The circuit diagram shows the alternator light, oil pressure light, and ignition going through the same connector so if it's completely disconnected those lights won't work either.

The wire from the sender is marked li/sw which I think means lilac & black so should be easy to spot.

[elmo makaroy]

ok i will have a look tomorow when i get the van back, the speedo does work but only kicks in when u go over 15-20mph, is this normal on an Aircooled van or should it kick straight in from 1mph?

[BOXY]

The speedo is cable driven from the front left wheel hub. The cable has a square end that's held onto a cap in the centre of the hub by a circlip. The square hole in the cap wears so it doesn't turn the cable on every revolution of the wheel. If your needle is "flicking" then the cable or the cap is probably worn and it isn't turning the cable on every revolution of the wheel. If it was all good the speedo would read as soon as you started moving.

[ewenmaclean]

Hello,

just to add a couple of things to the useful info that BOXY has already given you. The fuel sender is pin 7 in the infamous 14 pin connector underneath the speedo/clock assembly, and connects to a screw tab fixing at the bottom behind the fuel gauge. This gets its power from a voltage regulator which powers both this gauge and the temperature gauge. If the temperature gauge is ok then this regulator is working, and it's the sender side that's not working - I'd clean up the terminals on the 14-pin connector and check that the screw tab connector is good.

I'm not sure about Aircooled vans, but mine doesn't start reading until 10mph, so your behaviour sounds the same as mine!

Good luck finding the problem

Ewen

[BOXY]

Aircooled vans don't have a temperature gauge.

[ewenmaclean]

oops - good point! Sorry about that - I was just reading the tracks on the PCB I had and not thinking.... do you still have a pcb and the 14-pin connector though? If so probably worth cleaning up....

[BOXY]

There's a PCB, but the Haynes circuit diagram shows the fuel sensor wire going to T4c which is described as "CONNECTOR, 4 PIN, BEHIND DASH". The photos in the Haynes aren't very clear but I guess its in the same place as the 14 pin one on later vans.

Elmo, I noticed in you first post that you mentioned a new petrol tank was fitted before you got the van. Can you check with the previous owner to see if the fuel gauge stopped working when the tank was fitted? If it did the connector on the sensor probably wasn't re-fitted properly.

[bigherb]

The four pin connector is above the fuse box, look for a lilac with black trace wire.
To test the gauge use a length of electrical cable with bare ends probe one end into the connector of the lilac/black wire making sure it connects with the metal contacts and touch the other end to a good earth point, switch on the ignition the gauge should rise to a full tank, if it does the fault is with the tank sender or wiring, if not it is a fault with the gauge 'or dash connections.

[elmo makaroy]

thanks for the tip, i will try this on saturday as i have just picked my van up from the garage and im planning a day of playing with it

[Tatty Chap]

Did this work ?
I have the same problem (2.0l Aircooled CU), but frustratingly, it occasionally works.
Sounds like an iffy connection I guess. How does the sender actually work, could that be sticky, or indeed the needle on dash ?