W210 Rear Wiper Not Working. No power from dash switch to 40A FUSE.

[ringway]

Evenin' all.

My W210 rear wiper is not operating.

Changed 40A fuse and then had MB check out the fault (ouch!).

There is no current from the switch on the dash to the 40A fuse located under the rear seats, so there lies the problem.

The switch on the dash does illuminate though.

Is there anything obvious I could look for before I dismantle the front interior section to look for a break in the wiring?

Thanks.

Paul.

 

[bennesspipers]

Hi Paul, i have an idea,gonna ring you about 9ish

 

[renault12ts]

Hi Paul, i have an idea,gonna ring you about 9ish

Do share.

 

[alexander patie]

hello paul, did mb not tell you what the problem was? i cannot be sure, but i suspect the rear wiper is powered up by the pse unit - didn't you have a problem with this? certainly the switch does not carry the current, but is part of the ucp which cans the message to the pse - if that helps

 

[welland99]

pse unit, ucp

What are these?

 

[bennesspipers]

Wondering if your motors jammed up now, suggest disconnnect cable from motor,put switch ON & see if its live.

 

[ringway]

hello paul, did mb not tell you what the problem was? i cannot be sure, but i suspect the rear wiper is powered up by the pse unit - didn't you have a problem with this? certainly the switch does not carry the current, but is part of the ucp which cans the message to the pse - if that helps

Thanks Alex.

Yes I did change the pse control unit and it did cure all the problems with the central locking, interior lights,alarm etc..
I'll have a check to see if any more moisture is around the unit (surprised if there is now after my efforts to stop that problem).

MB (I'll call them to clarify) said that there is no supply from the front of the car to the 40A fuse under the rear seats and said that is where the problem lies. I assume (hope) they have checked the supply to the wiper from the rear seat point and found this to be okay.

The problem has progressed over a few months as shown on these threads below.

THIS thread.

AND

THIS thread.


The rear washer jets incorporated in the wiper DO function perfectly though.

 

[bennesspipers]

Having seen that last thread i bet your cable tween body & tailgate has been kinked & was shorting, & is now broken. Need to test tween w/motor & under back seat.

 

[ringway]

Cheers John.

Looks like I'm in for another busy weekend.

 

[bennesspipers]

If you're going to have to pull a new single cable through from tailgate to seat, disconnect both ends of old cable,pare back about an inch of old & new cables, twist tightly together (positioning the 'tail' of the twisted joint rearwards) spray cable & joint well with WD40,then slowly & carefully encourage it to pull & push through, spraying again at regular intervals to ask as a lubricant to ease the passage of the cable.

 

[ringway]

What are these?

A control unit located under the rear seats on the off side next to the battery.

Controls central locking and interior lights amongst other things.

 

[ringway]

hello paul, did mb not tell you what the problem was? i cannot be sure, but i suspect the rear wiper is powered up by the pse unit - didn't you have a problem with this? certainly the switch does not carry the current, but is part of the ucp which cans the message to the pse - if that helps

Correct again Alex! 10/10.

I thought I had cured the dampness/control unit problems. Yesterday the alarm started misbehaving again. Checked under the O/S rear passenger seat today to find the same water problem as before, although the control unit doesn't look as badly affected as the previous one.

I jacked up the car at the rear O/S to have a look underneath to check for a hole or similar and I could have watered the garden with the amount of water that came out of the N/S front wheel arch area.

I suspect a blocked drain in the windscreen area and will investigate.

Do you wear a beige mac and smoke a cigar sir?

Many Thanks,

Paul.