The fuel guage on my bay is not working properly. When I fill up it shows full but rapidly goes towards empty after 100 or so kays and shows empty when it only takes 17 litres to refill. I have tested the guage with a multi meter and found that there is 12 volts going to the petrol guage vibrator (funny looking box about an inch long and mounted in series with the guage and about 7-8 volts on the other side of the vibrator with this voltage sort of pulsing ie going up and down rythmically. I have earthed the other side of the gauge and it shows full when this is done. Does any one know the correct readings that should come out of the vibrator and does any one have any other sugestions? I also tried testing the wire that goes to the fuel tank sender unit from the dash and got no reading in ohms though my meter is pretty old and abused and is generally good for showing all or nothing. I once had a similar problem about 5 years ago and were advised to replace the vibrator but I cant remember if I actually did that or replaced the guage instead but what ever I did fixed it that time. Any help would be appreciated.
Cheers Nicko

Had the same problem with the fuel gauge sender in the fuel tank, and just changed the sender and hey presto, I then had a working fuel guage again. The lower part of the contact area the float arm wipes against had worn away and wasn't giving any feedback to the guage.

It's a bit easier in the twincab to change than a bus though

Mike

Nicko,

I agree with Mike, but first off, ground the wire at the tank end - to see if the gauge reads full?

This is what your sender probably looks like- nice and crispy, this one does the same thing, works when full but rapidly goes to empty after about 100k's.

You can get replacment senders from vintage gauge restorers or buy em new.

[Edited on 27-5-2004 by Kombi M@D]

Thanks for the advice. Looks like a bugger of a job with out taking the engine out
Nicko

To remove the sender unit your better off cutting a neat hole in the body work right above the sender unit to remove and replace it. Measure it carefully so you do cut too big a hole

This will save a few hours extra work by not removing the engine

Get some sheet metal and make a cover plate to go over teh hole and eitehr self tapper it or pop rivet it into place.

Just follow this diagram.

http://www.kulkathil.com.au/~natr/volkswagen/PROJECTTHREE.htm 

good luck!!

Thanks for the diagram. How low is the tank below the panel? I dont want to cut through the tank.
Cheers nicko

nicko


what a going to cut it with?

Tank is approx 75mm down, use a metal cutting blade on a jigsaw and put a peice of 10mm timber under the jigsaw (to protect the paint and also to raise the blade cutting depth).

If worst happens (you hit the tank) the jigsaw blade will merely bounce off of it. And frighten the shite out of you.

Have fun!!

I did this with our bus. I used an air hacksaw. I then got a slightly bigger piece of panel from another kombi and put that over the top which made it into a sealed access panel.

Hi Guys,

I have a '77 Twin Cab and the fuel sender needs replacing, similar to the above problems. Gauge reads full when wire grounded.

Question: I haven't removed one of these before, so before I start scraping around in there, how does the sender come out? There appears to be no screws or bolts, and things seem to suggest it levers out.

Is this correct? A blade screwdriver to lift?

Cheers
Craig

All Solved,

Twist (anticlock wise) and lift. Lack of headroom and a unit to compare with didn't let me see the arrow for lock and unlock positions.

Strange thing though - I tested the unit by lowering and raising the float bar manually out of the tank and the fuel gauge responds correctly. There's a mark on the float lever arm which indicates where it should make contact with the sender unit for a full tank.

I'm now not sure whether I am completely filling the tank. When the petrol bowser cuts off, there appears to be petrol in the filler unit. I'll experiment before replacing the sender unit.

Cheers
Craig

Craig the question is who cares what the gauge reads after you have pull out of the service station and you know that you have physically fill the tank to the brim

Dont forget as the fuel flower down the side of the van you washed it off with the watering can ... So its FULL

Its better to have the gauge more accurate at 1/2 full and at the reserve mark on the gauge. So check these settings next time you fill up.

whats the tanks capacity and what did it read before you filled it up...


Who ever herd of anyone running out of fuel when the tank is reading full just after you have filled it.