Sluggish wiper motor - and it's not the earth!

[JohnFol]

Morning all, about to tackle the slow wipers and noticed I get 10.6v between the block connector (disconnected from wiper motor) and battery -ve terminal. Battery is new, fully charged and connected to a trickle charger so somewhere between battery and block connector I'm dropping a few volts.
More than capable of tracing the wires through the fuse box, switches etc.  but hoping there are some well known places to look first.
Any thoughts appreciated

[peteracs]

Hi John

That is an interesting reading. Sorry no idea what reading you should get, but there are a bunch of wires going to the wiper to give the parking etc, can you say what voltage is on which wire and what switch position you have it on?

Peter

[HFStuart]

I've got a feeling that the wiper power goes through the column stalk control and through the two speed switch on the dash.  You could trace them and see what voltage you've got at each point or you could just rewire it with a relay or two.  Perhaps check the motor with a direct supply first to make sure it's not shagged.

[JohnFol]

I have a 12v supply on my bench so will run a few wires and see.

Thanks for the pointers regards the routing. Haynes has its uses but nothing beats a bit of experience.

[Nigel]

John,
Electrics acknowledged, but it's worth
removing the assembly from the car. Easy job but fiddly.

 The spindles can get very tight and are held together by a circlip on each. be careful,
they tend to fly, never to be seen again. Lithium or similar grease is best. Once you've disconnected the
motor from the arms you'll be able to feel if it's tight or not.

Regards, Nigel

[peteracs]

Hi John

I know your initial concern was with the motor disconnected and hence electrical, but I would check the mechanism for being partially seized. The main culprits as mentioned above are the spindles which have the wiper blades attached.

Peter

[JohnFol]

Thanks all. Backlog of jobs and a few days over xmas getting more full by the day.

[JohnFol]

Ok, time allows for some dis-assembly.

I've traced out the wiring and see there are 2 devices between switch and motor. One is a "windscreen wiper motor change-over switch" and the other is the "intermittance device". Wiring looks simple but finding them on the car is another story. Any pointers?