KjartanE

Just replaced my rear wiper motor on my 2005 ML320 CDi as the old one didn't work when I bought the car and I was told the motor was stuck. So no problem replacing the motor, but when testing it it only moved about 1/5 of the way each time (if switch was left ON). But if I put the washer ON then the wipers work flawlessly.

So just wondering what could be the problem. Any help would be appreciated thank you. Do not know if the is a relay or any adjustment/programming needed.

Maj. Dundee

Was the original motor completely dead and didn't operate at all?

Does the new motor operate the same way in both stages, intermittent and constant?

KjartanE

Hello. Yes the old one was completely dead. For the rear, there is only ON, no intermittent. You can turn it in a up direction and hold it there then the washer fluid comes on and the wiper works fine while holding it there, when turning it in downward position to ON it only moved small steps.

Maj. Dundee

One other question, what happens to the rear when the front wipers are on?

If you first wet the rear window, does it operate correctly?

Did you replace the liner yet?

KjartanE

Same behaviour when the front's are ON. No matter if the window is wet of dry, just travels like 1/4 of the way in small stepes. Yes the liner is in place. After some google I am pretty sure it is the relay in the rear sam, ELLA 4RA 007 793-031

Maj. Dundee

The relay is in the load compartment fuse/relay box, relay "P".

KjartanE

The motor I bought first was a 3rd party motor so after trying everyting I thought it might be the motor was faulty. So I bought a original Mercedes wiper motor and changed last night.....same results only moved about 1/5 of the way.

Have changed the Relay also, both P and one other.......

PLEASE, any input in this?

Maj. Dundee

First purchase wiper relay #002 542 26 19 from a dealer.

Then remove the tailgate liner and install new relay and check for operation. If not, then make sure the key is out of the ign. and the wiper switch on the steering column is in the off position.

Then remove the motor and follow the instructions in the PDF to see if it is in the PARK position. The reinstall the motor and check for functionality.

KjartanE

Thanks for the input, I went to the dealers and bought the Relay but when I came home there is no way for me to find where this Relay is supposed to be.... The photo that you sent is propably for a tailgate that has the wipers coming from the top of the window.

attached a photo of the tailgate with the linear removed, can you point me in the right discretion for this relay?

Maj. Dundee

Your original post says you have a 2005 ML and that is the location.

Post your full vin #.

KjartanE

It is 2005 ML.

VIN: WDC1641221A014483

Maj. Dundee

Look at your vin #. 164 means you have a 2006 ML. Now we have start all over again with this issue.

Please UPDATE YOUR PROFILE in USER CP to add the year 2006 ML320 CDI and where you live.

KjartanE

I did post this thread in the W164 section of this forum, but my car surely is 2005 (maybe Europe got those W164 a year before the US) as you can see in the decoder, and the registration for the car say's also 2005.

I really appriciate your help and sorry for this misunderstanding.

Maj. Dundee

You posted on the right forum but you said you had a 2005 and that is what I responded to.

You do not have a 2005 Ml which is a W163.

When are you going to update your profile because I am tired of typing?

KjartanE

Profile updated.

Maj. Dundee

The following procedures are done with the key in the on position and the wiper switch on the steering column in the off pos..

Locate fuse #50 and check both contacts on fuse for 12v. If not, pull fuse and see if it is blown.

Then at the rear wiper motor, locate the Blue/Black wire and have helper activate the rear wiper. Does the wire show 12v?