19 replies to this topic

[7builder]

My lad was out in his car today and the wiper stopped working then smoke started to appear from the switch in the steering column shroud. The wiper motor was replaced by the former owner about 6 months ago but the wipers have never self parked.
As I was near Calne I went to Somerford Mini Spares And bought a new wiper stalk and a Haynes manual. As the wiper motor was relatively new I thought it might be a short in the wiper switch itself. I replaced the wiper stalk after going through each fuse on the bulkhead, checking for any blown fuses. There is no cover on the fuses and nothing to identify which one is for the wipers so decided to check each one. None were blown but they were all quite corroded so I cleaned the blades with emery paper and electrical contact cleaner. I then connected the multi-plug connector for the switch and made sure it was in the off position. Unfortunately as soon as I turned the ignition on smoke started to appear from the new switch as well.
Vehicle electrics are my Achilles heel but I am guessing I have a short somewhere. I have studied the bowl of spaghetti that is the wiring diagram but struggling to pinpoint the culprit. Has anyone had a similar problem or any suggestions on how to find the problem? I have searched this forum and the web in general but not found anything.
Many thanks.

[Richie83]

I have a very similar problem at the moment. I've changed the park switch, motor, greased and it still seems to struggle to move the wipers and produces smoke from the wiper switch.

[Batmini]

Firstly, what age is the mini? (This will help with diagnosing the fault)
For mine (1977), it has the standard 4 fuse box and the wipers and washers both come from fuse 3 (between terminals 5&6).
For it to smoke, it sounds like a short. Has the plug been replaced in tge past? Also if it has never self-parked, this could be the problem. Double check the wiring on the self park switch (plenty of threads on here for it). These are mounted on the back of the motor and this is where you plug into the wiper motor.

Problem is now, you may well have fried the contacts in your new stalk switch.

[Batmini]

I have a very similar problem at the moment. I've changed the park switch, motor, greased and it still seems to struggle to move the wipers and produces smoke from the wiper switch.

If you disconnect the wiper motor arm, underneath the wiper motor cover, can you easily move the arms backwards and forwards by hand.

[David128]

burning of almost all electrical contacts is caused by bad connections ie arcing like a welder.and affecting the weakest point shorts will normally blow fuses . check all connections are clean and tight. A multimeter is your friend

[7builder]

Firstly, what age is the mini? (This will help with diagnosing the fault)
For mine (1977), it has the standard 4 fuse box and the wipers and washers both come from fuse 3 (between terminals 5&6).
For it to smoke, it sounds like a short. Has the plug been replaced in tge past? Also if it has never self-parked, this could be the problem. Double check the wiring on the self park switch (plenty of threads on here for it). These are mounted on the back of the motor and this is where you plug into the wiper motor.
Problem is now, you may well have fried the contacts in your new stalk switch.

Hi Batmini, the car is a 1986 Picadilly 998 with a 1275 SPi conversion. It is Ratty's old car that we purchased last week. We ran out of daylight this evening but will carry on investigating tomorrow after work. Thanks for the advice so far.

Edited by 7builder, 04 April 2016 - 08:35 PM.

[PaulColeman]

First up put the old switch back in because you know it;s not that that's causing the problem as the new one did the same. You may have already knackered the new switch but you my have been lucky - depends how long it was smoking for! But don't make it any worse and try it again after you've found the fault before you condemn it.

 

If you then unplug the wiper motor and flick the switch does it still smoke? If it does then it's nothing to do with the motor so you can rule that out. It's just a process of elimination.

Edited by PaulColeman, 04 April 2016 - 09:17 PM.

[KernowCooper]

Disconnect the wiper linkage from the motor and see if the wheel boxes and cable are tight ? 6lbs is the maximum pull

[Ethel]

The motor, or park switch, seem most likely to me. The wipers become live as soon as you turn the ignition on, so that they will park regardless of when the driver turns them off.

 

A stalled motor flows masses of current, enough to burn the wiring. As suggested above it's worth disconnecting the rack to see it isn't seized and that the motor runs with only itself to move.

 

The park switch also earths the +ve side of the motor to stop it dead when the switch is tripped. You can eliminate it as the cause of the self immolation by unhooking it from the motor, it earths via the metal retainer clip.

[7builder]

Thanks guys this is great advice and greatly appreciated. I'll get what I can done tomorrow depending on what time I get home and report back with my findings.

[7builder]

I removed the wiper motor along with the rest of the mechanism and this turned out to be seized solid. I stripped everything down, cleaned and regreased all the parts and reassembled. When I tried the wipers I got a whisp of smoke quickly followed by a blown 15 amp fuse. I then isolated the motor, replaced the fuse and tried again. When I switched on the ignition the motor moved briefly this time then blew another fuse.
I have ordered a complete wiper system, motor, tubes, wheel boxes etc as none of it was in good order but the question I have is do you grease or oil the worm drive cable before pushing it into the tubes or just grease the wheel box cogs that engage with the drive cable?

[David128]

messy job lots of grease fill all the grooves in drive cable, LM type.

[Ethel]

It's usually the wheel boxes that seize - that's the shaft the wiper arm fits on and the sleeve it runs in.

 

http://www.minispare...|Back to search

[7builder]

It's usually the wheel boxes that seize - that's the shaft the wiper arm fits on and the sleeve it runs in.

 

http://www.minispare...|Back to search

To be honest I think I managed to free everything up with regards to the wheel boxes and sleeves etc. but the threaded sections that stick out of the scuttle were so badly corroded I wasn't able to tighten the nuts down onto the rubber spacers so decided to go the whole hog and replace everything. I think the motor had an aneurism when it tried to overcome the forces required to budge the wiper arms so all in all one very poorly wiper system. The new parts arrive today so hopefully will have a slick system installed as soon as weather and time allow. 

[7builder]

Well I have spent all day on the case and I still don't have working wipers. I have replaced everything with new parts including the multi-pin connector that plugs into the motor but as soon as I turn on the ignition the 15 amp fuse blows. I have traced wires, checked resistance and condition of all connectors but there must be a short in the system somewhere and I can't find it.

I'm buggered if I know what to check next.