Hello all,

Last night I came back home under heavy rain, and my wipers didn't work at all RainX saved me and I made it safe but I want to fix this issue !

Where do I start ? They used to work, now nothing happens, what ever the lever position

Thanks

Antoine

fuses or contacts in fuse board?

All checked and ok contact cleaned and protected with "Electric contact" grease
It sadly is something else
Antoine

hmmm.
an earth? moisture.
sounds like all the rain might be connected.
could be co-incidence but......
have to haul out a wiring diagram and look for how wiper motor is earthed.
not something i have had to look into touch wood.

it could be in the steering column switch. thats a bit of a job. i'd look elsewhere first.
electrical stuff is my hoo doo. i leave that for my mechanic he is good at chasing that down.

-----

on fuses.
i remember someone once telling me about plastic core fuses popping on a 356 due to heat. the plastic expands. the old ones used to be a ceramic core, but that is not your problem. but.... i found myself a stash of the old ceramic core fuses off a merc guy. had to pay a bit to get them but its worth having those versus the cheap chinese copy fuses floating around on the internet. or you can sometimes find supplies of better quality plastic core fuses that date back a few years. whenever i go to the wreckers i look for old mercs to see whats left in the fuseboxes.

Yes, that might be a possible issue. I will try to find where it is connected to earth, in the meantime if anybody knows it, thanks for sharing !

Antoine

Any chance the wiring plug fell off the motor? You might be able to sneak a small mirror (or better, a bore scope) behind the fresh air box to see if the plug is out.

Good idea, I will check it today!
Otherwise I read about wiper arms/connections getting rusted/stuck.. To check it I need to disassemble it (meaning tank+fresh air box removal) or am I wrong?

Thanks

Antoine

you got the fact. manual?

6 things to check.
1. earth or leads, bad connection.
2. carbon brushes worn or sluggish.
3. insufficient tension of brush springs.
4. collector contaminated.
5. wiper bearings and joints of connecting rods without grease or binding.
6. battery voltage too low.

2 & 3 mean your electric wiper motor is kaput.
if you can get hold of an electrical tester you can establish if there is power to the motor and the earth is good.

2 and 3 will result in sudden loss of function. fuel pumps go the same way.
suddenly. but wiper motors don't get anything like the use of things like fuel pumps,
so i imagine an electric wiper motor can truck on for many years.

i'm wondering if 4 is a misprint/mistranslation and they don't mean commutator.
which is the shaft on the electric motor the brushes engage with.
so 4 is also the electric motor.

5. i think you would have noticed 5 along the way beforehand.

6. doubt its 6. if everything else is turned off and the car running and you switch on wipers and they don't work its not 6.

the procedure for checking the power to the motor is in the factory manual.
group 9 electrical.

if you are not getting power to the motor the problem is somewhere else.
switch in steering column or somewhere along the way.

work out if you have defunct motor first.

if you pull the paper duct of the interior air duct you can get at all the electrical connections easily. but after that!? like you said, it gets ugly. when i was recommissioning mine i found out why my heater blower was not working. wire had come off, it was around the back. i had the fuel tank out. for some reason it was easier to reach in there and discover that with the tank out. otherwise its a real pain getting your hand in there. thank you porsche. a bit like servicing the gearbox on a panther tank.

sadly to check 2,3 and 4 you have to get motor out.

Before pulling fuel tanks and tearing deep into the mechanics, I would do some basic troubleshooting to narrow down where the problem lies. You checked the fuses. Next I would use a multimeter to test the switch. Make sure power is getting to the switch, AND that the switch is sending power out to the motor when operated. Check with the schematics. Only after ruling out the switch would I start tearing into the front. That may very well be where your problem lies, but rule out the easy stuff first.

Mine stopped working and couldn't find why straight away then found wiring plug had come off to the switch connection,no issues since.

Thanks for all your help/Inputs. I now know what to do next and will keep you informed what worked!

Cheers

Antoine

Hello Antoine,

I had a similar issue with the wiper motor on my BMW E30 a couple of years ago. A short between the small coil and the copper lead that connects to one of the brushes. Problem solved within minutes (after 1 hour to remove the motor...).
Those motors are all built the same more or less. Pretty primitive but tough machines.
The small coils tend to break loose on the soldering spots and can be resoldered. Hopefully your problem lies outside the motor, though.

Good luck and keep us posted!

Arno

So, I checked a bit more:
Everything is connected, switch and motor.
I checked with an amperemeter as written in the porsche manual and no current between 53a and ground on the motor. So no surprise IT doesn't work.
Now I need to check the wiper switch. Not sure how to do it. My plan is to remove the bottom of the dash, clean all the connectors, test again and if no différence, check if some current comes into the switch (Black cable if my documents are right ?)
Cheers

Antoine

I think I found my issue here: http://www.914world.com/bbs2/index.php?sho...15825&st=20 as I noticed my horn is also not working! Now to search for a relay !!
Antoine

This is a 74? Did you check this fuse?

S8 16 Amp
Cigar lighter
Heater control assembly illum. lamps (3)
Fresh air blower indicator lamp
Fresh air blower motor
Windshield wiper motor

I exchanged the relay.. And everything works again!
Thanks all for the big help!

Antoine

thanks mate, red hot research into the archives.
i'm studying the wiring diagram to see how that happens.