Electrics issue- roof and wipers…?

[bigwinn]

I knew the project car would come with gremlins: here is the biggest so far

When roof is operated the window drop and the roof unlatches
However when the roof motor kicks in, so do the wipers???
Add to that the wipers don’t work off the column as per normal

Battery is good

Initial consensus suggests maybe some k-bus issues may be at fault

Any views/ideas?

Thx

Stuart

 

[Jas- USA]

Pull the fuse for the wiper and drop the top. If the wiper's go on without a fuse, the wiper's have another power supply, as well as a new on/off. Generally, something like this involves the k-bus

 

[bigwinn]

Good shout

 

[enuff_zed]

Unlikely but if you have a spare GM5 then swap it to eliminate that.
Are you able to do a code scan yet?

 

[bigwinn]

Unlikely but if you have a spare GM5 then swap it to eliminate that.
Are you able to do a code scan yet?

I reckon this weekend once all the abs circuits are back together

 

[bigwinn]

Had a quick play

Swapped the roof motor to check it’s not that at fault- same fault persists. The motor sounds like it’s labouring from low current as it’s turning but very slowly as the wipers move

Pulled all the fuses to the wipers- pressed the button and the problem is still the same!

Also lots of relay clicks from the dashboard while the wipers are running

I guess I need to pull a few relays next

 

[enuff_zed]

Unplug the wiper motor? Won't fix anything but at least then you'll see if the roof motor runs properly.

I'm guessing a weird earth somewhere.

 

[enuff_zed]

Looking at NewTIS I still think it may be something wrong in the GM5.
Whilst it doesn't really interact with the roof module, I know the roof won't move if the windows aren't reset, so there is a tenuous link there.

 

[bigwinn]

I have to say I am feeling the same...

The relays that control the roof up/down are buzzing like hell when the wipers activate... and the only common function linking the two is GM5...

 

[enuff_zed]

I have to say I am feeling the same...

The relays that control the roof up/down are buzzing like hell when the wipers activate... and the only common function linking the two is GM5...

Check the pins on the loom, you know what a faff that module is to unplug.

 

[bigwinn]

Barry (parts master south west region) is sending me a 12 star GM5 to test

 

[enuff_zed]

Barry (parts master south west region) is sending me a 12 star GM5 to test

Oh I assumed you had loads or I would have offered too. Sorry.

 

[Jas- USA]

If the car has an aftermarket radio or any other aftermarket item unplug then one by one and try the roof after each item is unplugged.

 

[bigwinn]

Well the gm5 swap made no difference

I’ll unplug the wiper motor next to see if that makes a change

Also noticed I have no hvac lights on the controls apart from the rear demister…

 

[bigwinn]

If the car has an aftermarket radio or any other aftermarket item unplug then one by one and try the roof after each item is unplugged.

What's the thought process here- that it may be affecting the k-bus?

 

[Jas- USA]

If the car has an aftermarket radio or any other aftermarket item unplug then one by one and try the roof after each item is unplugged.

What's the thought process here- that it may be affecting the k-bus?

Yes, I went to youtube under BMW K-bus. This is one of the many that came up https://www.youtube.com/watch?v=f8uab4lB6JA


Fast forward to around 3:00 and watch. He installed an aftermarket radio and it screwed up his k-bus. When he unplugged it the car returned to normal

 

[bigwinn]

Well I can but try. Thanks for the tip

 

[bigwinn]

Radio removed. No difference

Unplugged the wiper motor- all roof and window functions ceased nothing doing. Re plugged and the movement returned albeit with the inherent issues

I’m thinking earth issue or k-bus to sort

Onward!!