bizarre electrical issue

[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

[kawaden]

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

[Lionel]

X2.

Almost certainly an earthing problem!!

Cheers,

Lionel

[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.

[pop058]

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.

[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.

[Didge]

It's the "character" coming into effect :)

[pop058]

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.

[POD]

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.

[JDNSW]

I would look first at the earth for the column switches. For a start, its easier to access!

John

[jbe]

[QUOTE=POD;2499991]Perhaps an anger management course would help?
QUOTE]

If the semi driving next to you decides to change lanes without looking or indicating, some of us might be inclined to use the horn in self defence ;-)

[jbe]

Wohoo, problem solved!! I ran a beefy earth cable from the negaive battery terminal to the starter motor mounting bolt and my annoying problem has disappeared. I ran out of time, but I will also run another cable from the starter motor to the body to be sure :). Thanks everyone for your input.

[Blknight.aus]

check the condition and adjustment of the hand brake cable as well.

if replacing the engine earthing strap fixed the issue then at least some of the current for starting and charging has been being transmitted through your handbrake cable.

[jbe]

check the condition and adjustment of the hand brake cable as well.

if replacing the engine earthing strap fixed the issue then at least some of the current for starting and charging has been being transmitted through your handbrake cable.

Will do. Funny you mention that. The handbrake felt different today.

[Blknight.aus]

its a PITA,

to me that suggests replace it or it will do one of 2 things.

1. snap
2. seize and it will seize in the applied position.

[jbe]

On a Easter 4WD trip, my electrical issue has come back and got worse:

- when I use the horn, the windscreen wipers run four times (which is the same interval as when you press the windscreen wash button) when the ignition is on II.
- when I press the windscreen wash button (ignition on II), the horn sounds some times, but not as loud as when pressing the horn button

- when I disconnect the wiper/washer switch completely and press the horn switch, the wipers don't run. Could it be this switch??

As far as I can see, the wiper inrteval is somehow controlled by the ECU. Is this correct?

I am starting to think that this is not an earth issue and I'm leaning towards some sort of fused wires.
I also noticed that No 20 fuse was blown and when I replaced it, it blew again. According to the manual, it is supposed to control headlight dim/level. Is that correct? As my car doesn't have this feature, I pulled the fuse and haven't lost any function. However, it hasn't made any difference.

I'm a bit at a loss where to start. Is it a matter of checking the entire wiring loom between the switches, the ECU and the wiper motor and the horn??
This would be a monumental task.

Any help would be appreciated.

Cheers
Joachim

[jbe]

One more question:

where is the earth for the column switches located?

[schuy1]

How does the operation of the column stalk feel? If it feels loose/notchy/vague there is a possibility it has malfunctioned, as in melted or broken the plastic that contains the different contacts allowing them to touch causing your faults. Sorry, Im not up on the TD5 earthing for its switching although it may use a BCU like the disco which switches earthing if I recall. a wiring diagram would help you as in the RAVE
Cheers Scott

[jbe]

How does the operation of the column stalk feel? If it feels loose/notchy/vague there is a possibility it has malfunctioned, as in melted or broken the plastic that contains the different contacts allowing them to touch causing your faults. Sorry, Im not up on the TD5 earthing for its switching although it may use a BCU like the disco which switches earthing if I recall. a wiring diagram would help you as in the RAVE
Cheers Scott

Hi Scott

Thanks for the response. The stalk feels vague/worn. I'll have a close look at it tomorrow and I might just change both switches for a start. I have the wiring diagram. As far as I can see, there is no common denominator between the horn and the wiper signals as far as I can see.

I still haven't found the column earth, JNSW was talking about.
Cheers
Joachim