Wiper problems

[Polly-Red7]

Have posted the following in "ask the experts" but posting here too to seek advice
Hello!
A quick question! Are the wiper box electrics known for having any problems due to moisture? The reason I ask is that on two occassions now I have set off in the 7 on a cold damp morning (a heavy dew) for the wipers to grind to a halt after about 2 wipes. When I then get to have a look on my day off they are fine??

I've obviously lubed the box and checked it over, although I haven't examined the bushes as yet. It just puzzles me that it only happens when cold?

Cheers in advance Chris

[FI Spyder]

Not having any wiper problems like that, I can't specifically suggest a problem. As a matter of course when I was cleaning every contact on the car in the winter before my "from out of country" safety check, I took the mechanism out of the car, took out the rack, cleaned and greased with synthetic grease, same with the boxes,opened the motor box and cleaned and greased what I could without actually getting into the motor. Be careful of the copper parking switch tang (I cracked it and it soon later broke requiring me to resolder it with a reinforcing strap of copper) and had to readjust the switch once to get it in the right spot to properly park the wipers. They have been dead reliable in the intervening 8 year and 20,000 miles since through spitting rain to driving rain storms. While the clean out grease wasn't particularly hard the lighter synthetic might be better but the most important is cleaning every electrical contact in the circuit to ensure the motor is getting the full voltage and amperage to do it's job. The recommendation I would have for any one doing this is to wrap the parking switch tang so it doesn't get caught on anything and break and expect to have to adjust the switch when reinstalling (you might get it right first time).

[busheytrader]

Hi Chris,

I had the same issue back some years back and it was down to poor connections in the loom and switches as the copper contacts were coated in green grunge / corrosion. The current just couldn't get through. Cleaning them up made a difference as did replacing the old hardened grease in the rack with fresh stuff. Wiper speed improved by about 20% in the wet and stopped them stalling on a dry screen.

I also had something unique to mine. A previous owner (there had been 5 or 6 before I bought it at 6 years old) had cut the wires a few inches before the switch on the steering column only to join them up again by twisting the wires together and wrapping in masking tape. The tape was so old I thought it had been left on by the factory. Soldering proper joints improved the wiper speed by about another 20%. Checking through the loom from switch to motor casing and cleaning up the connections may bring back the wipers from the dead. Don't dismantle the wiper switch on the column unless it's your final hope. There's a wire spring in there that will exit at high speed at the earliest opportunity and it's a pig to get back in the correct position. Mine flew out to the opposite end of the garage. There were a couple of threads on the forum about this.

Hope this helps,

Adam

[Polly-Red7]

Thanks for the replies gentlemen. I've also had a reply on my Facebook posts regarding the same and it appears in the States this problem was subject of a product recall which involved fitting a rubber boot to the motor! But I shall have a good root round tomorrow based on your advice and see what I can find

[FI Spyder]

I don't know how the rubber boot would solve the problem except maybe try to keep it more water proof in down pours? This goes back to my old saw, any time you have a wire connection (or contact of any sort) you can have corrosion, even if you have grease in there (like in some switches) the grease will dry out after 35+ years and it will still corrode. You can clean every contact (or switch) in the car (as time permits, a good winter project if the car is in the garage) and have trouble free electrical (relatively) motoring or you can wait until it causes a problem and tackle it one by one which can happen at inopportune times and often (there are a lot of contacts).

[Polly-Red7]

Hear is the screen grab that was posted to my Facebook query, but I will strip the box again tomorrow and clean all the contacts. It just puzzles me it only happens in cold damp weather?