At the last event we attended, it started to rain. No drama in that, just switch the wipers on – but no response. All dead. Wiper motor being more than nice to have, this required immediate attention.
Not being too familiar with the Jaguar Mk2’s electrical system (yet – I have a feeling I will get to know it more in details), it took quite some time to figure this out. Also new motors are hard to find (sticking to the original style) and/or expensive. On other classic cars I’ve normally ended up with having to replace the wiper engine or the switch.
First thing was checking the fuse box. It was dirty; a cleanup was required. The two fuses were both intact. Another thing was that other elements connected to the fuses were working, so this was not likely to be the problem anyway.
There was no response when toggling the switch on the dashboard, so I continued there. Unscrewing the two thumb-screws in the mid-section, tilting the section down. Good thing to remove the cigar lighter and key first. Unscrewed the switch, removed the leads and checked all connections. Seems to be all good – could still be the switch itself.
Focus move to the original wiper motor. First thing noticed – the ground cable was broken. This was replaced, still no action. Opened up the top of the wiper motor via the two screws. These goes through the box, so be careful when removing. Inside it was a mess, the cables and connecting points were awful – almost no cable left, most 90% thorn of, also at the point where all the cables came out of the box, the isolation was gone on half the cables – short cut mania. The brushes were checked ok, the rotor was cleaned. First some half-gentle cleaner fluid, and dried off with high pressure air. Cables going out of the box, 6 in all, where replaced (some soldering needed – requires a steady hand), and extra isolation was applied where they exit the box.
New test. Ignition on, then the switch. Hey – it worked, wipers moving as they should. But what?? I could not stop the wipers again – they kept going as long as the ignition was on. Not exactly what I wanted. Ok, the ground was pulled off, and the wipers stop. Still the hand break light/ignition lamp inside the car, was going from fully lighted to half bright in interval, even though nothing should pull power. A short cut? One by one I pulled the bullet connectors applied to the incoming cables to the wiper motor. One cable triggered the ignition lamp to stay normal. This cable went through the motor, via a connection point, and out a hole in the bottom of the box and further in the wiper mechanism. And there it was, the short cut. Isolation totally worn off, shortcutting the point where the cable went out of the motor box, to ground. Cable replaced. Wiper worked perfectly (or as it should, at least).
It made sense, because the wiper motor is screwed to the engine bay’s side with thick rubbers due to the engine/motor shaking when running, thus the isolation on the exit point of this particular cable gets some stress over time.
Anyway – case closed – ready for rainy days again.
How electric motors work - explained here: http://en.wikipedia.org/wiki/Electric_motor
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| Not the cleanest inside of a motor I've seen. This is before the actual work got started |
First thing was checking the fuse box. It was dirty; a cleanup was required. The two fuses were both intact. Another thing was that other elements connected to the fuses were working, so this was not likely to be the problem anyway.
There was no response when toggling the switch on the dashboard, so I continued there. Unscrewing the two thumb-screws in the mid-section, tilting the section down. Good thing to remove the cigar lighter and key first. Unscrewed the switch, removed the leads and checked all connections. Seems to be all good – could still be the switch itself.
Focus move to the original wiper motor. First thing noticed – the ground cable was broken. This was replaced, still no action. Opened up the top of the wiper motor via the two screws. These goes through the box, so be careful when removing. Inside it was a mess, the cables and connecting points were awful – almost no cable left, most 90% thorn of, also at the point where all the cables came out of the box, the isolation was gone on half the cables – short cut mania. The brushes were checked ok, the rotor was cleaned. First some half-gentle cleaner fluid, and dried off with high pressure air. Cables going out of the box, 6 in all, where replaced (some soldering needed – requires a steady hand), and extra isolation was applied where they exit the box.
New test. Ignition on, then the switch. Hey – it worked, wipers moving as they should. But what?? I could not stop the wipers again – they kept going as long as the ignition was on. Not exactly what I wanted. Ok, the ground was pulled off, and the wipers stop. Still the hand break light/ignition lamp inside the car, was going from fully lighted to half bright in interval, even though nothing should pull power. A short cut? One by one I pulled the bullet connectors applied to the incoming cables to the wiper motor. One cable triggered the ignition lamp to stay normal. This cable went through the motor, via a connection point, and out a hole in the bottom of the box and further in the wiper mechanism. And there it was, the short cut. Isolation totally worn off, shortcutting the point where the cable went out of the motor box, to ground. Cable replaced. Wiper worked perfectly (or as it should, at least).
It made sense, because the wiper motor is screwed to the engine bay’s side with thick rubbers due to the engine/motor shaking when running, thus the isolation on the exit point of this particular cable gets some stress over time.
Anyway – case closed – ready for rainy days again.
How electric motors work - explained here: http://en.wikipedia.org/wiki/Electric_motor
