Thread: bizarre electrical issue

Originally Posted by jbe

I have a bizarre electrical issue with my 2005 TD5 defenderand I hope this is the appropriate section to post my question. I also searchedthe internet quite a bit for this issue, but it doesn't seem to be common.
Here we go: I noticed that when I honk the horn in theDefender for more than three seconds (or thereabouts) the windscreen wiper willcome on for approx. 30 seconds and then stop again.
I am not sure where to start diagnosing the issue as thehorn and wiper circuits shouldn't have any common point.
Any constructive input into my problem would be greatly appreciated.
Cheers
Joachim

check your earths for those circuits

X2.

Almost certainly an earthing problem!!

Cheers,

Lionel

Will do. Thanks for that. Do you know where the earth for the wiper motor should be? To my knowledge, the wiper motor was replaced before I bought the car three months ago. When I had a quick look at it, I couldn't see anything.

Originally Posted by jbe

Will do. Thanks for that. Do you know where the earth for the wiper motor should be? To my knowledge, the wiper motor was replaced before I bought the car three months ago. When I had a quick look at it, I couldn't see anything.

That, I think is your first clue.

Agree. Not what I wanted to hear . It's about the fifth time, I have to pull the dashboard apart for various reasons.
Anyway, an earth issue would be easier to fix that a buggered wiring loom.

Can anyone tell me if the wiper motor is supposed to be earthed directly (I couldn't see any earth wire when I looked at it last time), or if the earth cable goes back through the loom to somewhere else.

It's the "character" coming into effect

Originally Posted by jbe

Agree. Not what I wanted to hear . It's about the fifth time, I have to pull the dashboard apart for various reasons.
Anyway, an earth issue would be easier to fix that a buggered wiring loom.

Can anyone tell me if the wiper motor is supposed to be earthed directly (I couldn't see any earth wire when I looked at it last time), or if the earth cable goes back through the loom to somewhere else.

IIRC, the wiper motor is supplied with (key on fused) power all the time and the 2 internal wiring field earths are switched. This gives you the 2 speeds as well as self parking when the wipers are turned off.

Originally Posted by jbe

when I honk the horn in theDefender for more than three seconds

Perhaps an anger management course would help?

As others have said, most likely an earth problem- the words 'bizarre electrical problem' in your thread title screamed 'bad earth' before even reading the post. I'd be looking for a bad earth on the horn rather than the wipers.