Hi, I've got an annoying problem that has been bugging me for nearly 20 years.

My wipers don't switch off once they are turned on.

I went thru three VW mechanics but none of them have been able to fix it.

Can some one recommend a good auto electrician familiar with vintage cars?

You could try Simon on 0408 178 211. I bought a changeover starter from him and he seems happy to work on old cars including VW's. Works from home
Cheers

Possibilities;

Switch defective
Park contact in wiper motor defective
Bad earth from switch

You could disconnect the ignition wire to the wiper motor and then park it manually as a temporary fix.

It's not a 6 volt car converted to 12 volt by any chance? Dave

Most vintage cars have crappy earthing. As this problem has been annoying you for 20 years, spend 4 hours (that's .00228% of twenty years, a quite trivial amount) on cleaning up your earthing. Remove each earthing screw, sand down to bare metal and replace. It is unlikely to solve your problem, but will improve your karma.

hth

Use the samba to look up the wiring diagram for your Bug and check the wires are on the right terminals. It just takes the 2 live feeds to be swapped and the park function will never work.

What is the wiper motor, 6v or 12v?

That may be your problem. Try disconnecting the black wire from the wiper motor and park it manually.

It shouldn't make any difference if still on the 6v motor armature or the Wolfsburg West 12v armature has been fitted. This is cos the park function is part of the base of the motor where the gearing is. There is a cam that operates a contact where the 3 wires enter the motor. It is this contact that allows power to be kept on after the wiper switch has been switched off and keeps the power on until the park position is reached. At this point the contact opens to remove the permenant live and stops the wiper at it's park position.
From experience, if you mix the 2 wires from the switch to the wrong motor terminals then the wiper will switch on but never off IIRC.
Maybe worth taking the base of the motor apart to check out if the parking cam that opens the contact is working properly.
Those early motors are very basic single speed and the Wolfsburg armature just corrects the wire gauge and hence resistance so the correct current is drawn by the motor. Nothing more than that as the stator is just a laminated magnet and not an electro magnet as in a dynamo, alternator or modern motor.

Dunno his surname. Just call him up and explain what you are after

I should mention that the wipers do turn off eventually.

Let me explain the problem in full.

If I turn on the wipers when I do not have the engine on - it will switch off as normal. No problem

If I'm driving and I turn the wipers on - the wipers may not turn off. It seems to be esp worse when it rains. The wipers will operate but slowly - like at half speed.

My wipers has only one switch on speed.

Usually the solution is to turn the engine off and the wipers will switch off. Then I turn the engine back on and the wipers will hopefully stop - sometimes they do.

I had a look at the 64's wiring diagram and the wiper switch power should come from the ignition switched live fuse. It dies the brakes, indicators and horn too.

The engines coil is from that fuse but from the unfused side. So maybe there is voltage drop across the fuse itself from oxidation to the fuse box terminals and/or the fuse itself. That could expalin the slow running when the engine is running.

My other thought was that maybe the wiper switch itself is all gummed up inside and the wet may just mean the increased humidity is allowing a current path to form in the switch. Maybe pop a cheap 10amp rocker switch in place of the current switch to see if that helps. If it does you can then buy a new correct style switch