Electrics issue- roof and wipers…?

bigwinn · Post by **bigwinn** » Mon Apr 29, 2024 8:43 pm

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 · Post by **Jas- USA** » Mon Apr 29, 2024 11:42 pm

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 · Post by **bigwinn** » Tue Apr 30, 2024 7:02 am

Good shout

enuff_zed · Post by **enuff_zed** » Tue Apr 30, 2024 7:22 am

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

bigwinn · Post by **bigwinn** » Tue Apr 30, 2024 7:43 am

enuff_zed wrote: ↑Tue Apr 30, 2024 7:22 am 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 · Post by **bigwinn** » Tue Apr 30, 2024 10:17 am

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 · Post by **enuff_zed** » Tue Apr 30, 2024 11:16 am

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 · Post by **enuff_zed** » Tue Apr 30, 2024 11:23 am

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 · Post by **bigwinn** » Tue Apr 30, 2024 11:27 am

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 · Post by **enuff_zed** » Tue Apr 30, 2024 11:41 am

bigwinn wrote: ↑Tue Apr 30, 2024 11:27 am 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 · Post by **bigwinn** » Tue Apr 30, 2024 11:52 am

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

enuff_zed · Post by **enuff_zed** » Tue Apr 30, 2024 3:11 pm

bigwinn wrote: ↑Tue Apr 30, 2024 11:52 am 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 · Post by **Jas- USA** » Tue Apr 30, 2024 9:12 pm

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 · Post by **bigwinn** » Wed May 01, 2024 6:00 pm

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 · Post by **bigwinn** » Wed May 01, 2024 9:25 pm

Jas- USA wrote: ↑Tue Apr 30, 2024 9:12 pm 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?

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