wipers..... again

I know that people are going to say it's the switch, it's the relay, it's something else, and I would agree if only I've tried 2 switches, 3 relays and 2 motors tonight and the only thing that works is putting the motors on the plastic scuttle tray. I've a handful of blown fuses too. When I checked the motors I found the 2 live feeds to the slow and fast windings are shorted to the casing of the motor. This doesn't make a lot of sense but explains the symptoms of the fuse blowing instantly. Anyone got a spare motor that they can check for me? The 2 wires are the 2nd and 4th across the 5 way connector.

Tried again with another motor, relay and switch. It all works fine with the motor sat on top of the engine, touching the engine earthing points, but attach it to the wiper frame and the fuse blows instantly. I thought it might be overloading due to the linkages being stiff, so tried it with everything disconnected. No change, blew the fuse. Running out of ideas now.

send me your email & I'll dig out a wiring diagram for you
MP

I've got the mk1 and mk2 Haynes manuals to hand. It's not helping though. I've even stripped a wiper switch to check the operation. It happens with non intermittent and intermittent relays. It doesn't make sense that the wiper frame has such an effect. I initially thought that it should be isolated but earthing the motor through the engine changed that. I can't see any way that too much current can flow as there are no shorts to ground that I can find.

like I said - PM me with you email * I'll dig out a wiring diagram that might help - not the haynes dio - something a little clearer

The latest - When I have the motor running and touch earth, there's a huge spark and the fuse blows. Now does this mean that the wiper brackets are meant to be insulated? I'm sure I measured the resistance between the casing and earth and it was virtually zero.

why do you not get the wiring diagram and go from there????

yeha said

The latest - When I have the motor running and touch earth, there's a huge spark and the fuse blows. Now does this mean that the wiper brackets are meant to be insulated? I'm sure I measured the resistance between the casing and earth and it was virtually zero.

I think this means that the outer casing of the motor is live, and touching it to earth creates the short circuit which causes the fuse to blow.

It's strange that changing the motor still causes this effect - perhaps it's the connector or wiring which is at fault, meaning that the casing of any motor is live once it's switched on.

I'd be surprised if the wiper brackets were supposed to be insulated from the earth, as it's all metal and connected by metal screws to the bodywork.

Seeing as you've eliminated the switch, the relay, and the motor from the equation, I think the wiring is probably worth checking next.

HTH

Rich