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rear wiper motor.

Posted: Tue Mar 05, 2019 2:46 pm
by dekkb
Hi all, I'm sure there's a million threads about this somewhere, but i can't find it.....yet.
my rear wiper motor isn't working (nothing new), I've tested the motor and it's fine as is the original and replacement stalk. Naturally I assumed it was the usual dodgy wiring around the hinge area but after a bit more investigation I'm not sure.
There appears to have been several soldered repairs at some point in the past so I thought I'd just check everything over before running a new loom and have found that power must be getting through somewhere as when you swap wire numbers 2 and 3 at the motor connecting block(mine have printed numbers on them) the damn thing works, continually.
so, whats going on? as found wiring, nothing swap two wires runs continually. I've written down the colour and wire number combos but don't have them with me, if anyone has any idea s they would be really useful. TIA, Dekk

Hopefully I'll have posted enough soon so I'll be able to add some photos of the 480

Re: rear wiper motor.

Posted: Tue Mar 05, 2019 4:28 pm
by jifflemon
It's going to be the hinge wiring - it always is!

You've got 3 wires to wiper. I earth, one power and one park power. I'm guessing you've lost power as from the sounds of it,swapping the parking power has got the motor running.

I'm doing a similar exercise myself at the moment, so I'll try and post up my findings.

Re: rear wiper motor.

Posted: Tue Mar 05, 2019 5:46 pm
by dekkb
Flippin' thing :lol: I think I'd just rewire the whole thing, it wouldn't take half an hour but its that rubber grommet tube thing that's stopping me. I suppose it could be swapped with shrink wrap or sliced open and reused then sealed?

Re: rear wiper motor.

Posted: Tue Mar 05, 2019 6:14 pm
by Alan 480
dekkb wrote:
Tue Mar 05, 2019 5:46 pm
it wouldn't take half an hour but its that rubber grommet tube thing that's stopping me. I suppose it could be swapped with shrink wrap or sliced open and reused then sealed?
yep thats the option I resorted to, sliced it open, then wrapped it (the grommet thing) in self amalgamating tape, pulled tight to keep it as thin as possible to avoid/reduce leaks :wink:

i moved the broken wires area away from the hinge, from memory I found 'extra' length at the wiper motor end so that my soldered area was within the roof area

hope you get on OK

Re: rear wiper motor.

Posted: Tue Mar 05, 2019 7:10 pm
by dekkb
Cheers Alan, I've got the correct wire so I'll just make it a bit longer and work out a way of sorting the plug end, the rest is nice and simple....... Maybe.

Re: rear wiper motor.

Posted: Tue Mar 05, 2019 8:24 pm
by dcwalker
As others have said, almost definitely the wiring. The only other option is the relay in the CEM...but that's a very outside chance with 480 rear wipers!

Good luck!

David

Re: rear wiper motor.

Posted: Wed Mar 06, 2019 9:18 am
by dekkb
dcwalker wrote:
Tue Mar 05, 2019 8:24 pm
As others have said, almost definitely the wiring. The only other option is the relay in the CEM...but that's a very outside chance with 480 rear wipers!

Good luck!

David
just a thought, would the relay also be the one that controls front wipers intermittent function? that's not working either and I've been told that is probably the relay.
I'm hoping not as I've got to CEM's neither and are perfect, the one I use has a bypass wire to the ignition otherwise it wont start :cry:

Re: rear wiper motor.

Posted: Wed Mar 06, 2019 10:02 am
by jamescarruthers
dekkb wrote:
Wed Mar 06, 2019 9:18 am
just a thought, would the relay also be the one that controls front wipers intermittent function? that's not working either and I've been told that is probably the relay.
I'm hoping not as I've got to CEM's neither and are perfect, the one I use has a bypass wire to the ignition otherwise it wont start :cry:
The lack of intermittent front wipers is likely to be that the contacts on the throttle cable are broken at the bulkhead. You can't fix them‎ (although I would be interested to hear if anyone ever has!). 

There was a feature that when you depressed full throttle, some contacts would be broken and the intermittent wipers would switch to continuous and the air conditioning would be switched off. ‎When these break, the CEM sees full throttle and changed intermittent wipe to continuous and there's no way to have intermittent back.

If you lie upside down in the driver's footwell you ‎should see two spade connectors on the throttle cable as it goes through the bulkhead. Disconnect them, add in a link wire between them and you should have the wipers restored to having intermittent operation.

‎This was completely deleted on later cars, in which case look elsewhere, as suggested, at the CEM relay instead. ‎

For planning purposes (to reduce squeezing yourself in to the footwell more than you have to!), the spades are two different sizes‎. So you will need a small wire (about 1" long)  with a big and a small male spade connector to plug in; or just cut and join the wires together but it's really fiddly under there and a plug-and-play solution is easier.

If you have some old scrap speakers lying around that have double terminals on them to go to tweeters, you can break off the connector and use this instead. This is what is on two cars I restored the intermittent function to.

Re: rear wiper motor.

Posted: Wed Mar 06, 2019 10:08 am
by jamescarruthers
This isn't related to your problem but when you get the rear wiper working again and restore the intermittent front wipers, check one more feature.

When intermittent rear wipe is selected (either speed) or the front wipers are on (any speed), if you select reverse gear, the rear should switch to continuous operation.‎

Re: rear wiper motor.

Posted: Wed Mar 06, 2019 3:30 pm
by dekkb
Really useful to know, cheers. I'll try and have a look tomorrow lunchtime as that sounds fairly easy and the lack of intermittent is far more annoying than the lack of rear wipers.
As for the reversing wiper function, I do remember reading about that but had forgotten, be good to see if that's broken too :lol: