G'day everyone
i have a 1974 L bug that has a fuel guage that only shows half a tank (for a little while) when full then pretty well does what it likes after that. Shows sometimes a little over full but not very often. Any ideas on the best plan of attack to fix it. I was told to have a fiddle with the wires at rear of guage ! There seems to be a kinda inspection plate in the bonnet that would be behind the dash so I am thinking I should "fiddle" in there first. Any traps I should be aware of. Any advice would be appreciated.

Thanks

Fiddling with your wiring may not be the answer, but you can give it a go.

I was told that the voltages of older VW's can change pretty dramatically depending on the operating conditions, which will effect all of your electronics. This can make your lights dim or get brighter, and make your gauges a treat to read.

From your explanation though, it could be a bad contact, so by all means check your wiring. By the same token, 30 years has been a good life, and sometimes you just have to bite the bullet...

BOL - you'll get a better response tho' in the Tech section.

hmmm... i have the same problem with my fuel guage.
ive become very good at knowing how much fuel is in my tank and when im about to run out of fuel (and have only run out of fuel once!)

but strangely enough, these past few weeks have seen my fuel guage behaving like a perfectly working fuel guage, evn tho i know that is not the case.

i think its time i get one that knows what its talking about!

its a 90% chance that its Your Fuel tank sender....
its a mechanical device that does wear out with time...
I believe they just unscrew from the tank in Your model..
Just make sure the ignition is turned off.... I don't think You need to disconnect the battery as there aren't all the wires that standard beetles have in the front section...
Fuel gauges are usually trouble free...

regards

Lee

I know the feeling, the '69 I bought recently has such a berserk fuel readout that I have basically ignored it. I have fiddled behind the dash and reckon my connection on the back of the gauge is crook, and have just finished putting in a brand new wire and connectors to see if this fixes it. I have also given the two pins a light going-over with sandpaper to clean the edges, will testdrive it later tonight and hope that this does the trick.

When the gauge is going I get a huge difference in fuel after going around corners, can be up to half a tank, is this normal? A bit disturbing when you come to a corner with half a tank and after you have turned you have an empty tank...!

I agree with Lee, check the sender. It went in my kombi and it only worked at the very top part of the range (tank near full). Apparently this is b/c they spend much more time in the lower part of the range so that's where it wears out.

thanks everyone
Hopefully the car is on the road in a couple of weeks and I will soon know if I have fixed it or not. Have never run out of petrol before so I may be in for a new experience !

fuel senders are in essance a wire wound resistance grid. as the float in the tank moves up and down it shorts out the wire which then gives out a different voltage to your guage so that gives you empty to full etc. well thats my understanding of them. so when they dont work properly its just as easy to replace it with one that works. either that carry a 5 ltr fuel tin around with you :thumb:

He He.

Even after replacing the senders in both the bus and the Beetle, Fleur still has to have a spare fuel tin because she just runs out.

I might as well have not fixed them, except I would not know how much fuel was left when I would go for a drive.

sender for sure or im a monkeys uncle

I had some big problems with my gauge. One day I noticed it was stuck on empty. I checked the gauge out and the wire had actually broken like a fuse. So I resoldered it but then it would only show half a tank. I knew it was wrong the first time I ran out of petrol, oddly enough just as I'd parked the car.

Since then I have relied mainly on intuition to know when I'm out of fuel. This isn't fool proof as I ran out again on a big, but thankfully quiet at the time, road.

Anyway I checked mine again recently and it looks as though the wire has broken somewhere along the coil that runs along the needle. One day perhaps I'll get the wiring sorted and then replace the gauge.