RCZ wipers not working

[Des101]

Hi, can anyone help with what looks like an electrical problem with my RCZ's wipers?

A little while ago, they stopped working; they wouldn't turn on at all. Whilst I was messing with the stalk switch, they eventually came back on for about 30 seconds, then went off and have never come back on.

ThinkDiag reports 002F - "No communication with the Windscreen Wiper ECU" and 09B3 - "Engine fuse box fault. Absence of comms with the the windscreen wipers master motor on the LIN".

I've taken everything apart, removed the battery and tested the wiring and it all seems fine.

Today, I've disconnected both wiper motors and put an oscilloscope on the connections. I can see an active signal on what I assume is the lin bus (9051). But there's nothing on any of the other pins. The fuse is fine and showing 12v on each side.

So I presume I'm missing a driving voltage on 500/501, which I'm guessing is missing due to either a faulty relay or a fault with whatever provides the switching signal to the relay.

Does the above sound reasonable? and what should I do to track the problem down further? I'm not familiar with car electrics (but know electronics in general), so I'm sure under what conditions the wiper units get powered on (the schematic for the relays on PSF1 look confusing to me, so I'm not exactly sure how they're supposed to work).

I haven't taken the wiper units apart yet, there doesn't seem much point if they're not getting any power.

I'd be really grateful for any advice.

Des

[PaulC5]

How old is the car and mileage ? Often wipers that do not work properly is due to a wiper motor fault due to wear or water ingress in to its motor.

[Des101]

Thanks for the response Paul, it's all sorted now.

For anyone who comes across this thread with similar symptoms, the problem was the fuse box, I assume a relay had stuck open or closed. Replacing the fuse box unit fixed it.