rear wiper will not stop

[Leto Atreides II]

Today my rear wiper all of a sudden will not turn off. It has been working fine until today when I turned on the car after picking my wife up from the airport. The rear wiper just started wiping all by itself as soon as I turned the key and would not turn off. I had to remove the rear wiper fuse to get it to turn off.

Any ideas what might be the culprit?

[Willy]

Could be a stuck wiper relay Item 2/72)
Willy

[Leto Atreides II]

Gah, no wonder I couldn't find the relays... The layout is completely different starting 2005. My fuse box in the rear looks like this:

http://new.volvocars.com/ownersdocs/2005/2005_XC70/05xc70_08a.htm#pg134

Where the heck are my relays? From the wording in the manual it sounds as if the relays are all up front, but that doesn't make any sense and there's nothing up there for the rear. Anyone got a diagram for me?

[Art]

You'll need to remove the left-hand side panel to gain access to the relays.

http://i20.photobucket.com/albums/b249/Batstar/SidePanel.jpg

[Leto Atreides II]

Judging from the wiring diagram I found it looks like there is no relay, it is simply controlled by the CEM (REM actually, I think it is mislabeled). (Page 90)

http://www.matthewsvolvosite.com/downloads/2005_V70,_V70R,_XC70,_XC90_wiring_diagram.pdf

[Leto Atreides II]

Art, I'd already taken off the side panel, but there are still no relays visible.

[Art]

Yep, you're absolutely right Toby. Must have changed at MY2005. My '06 also is missing the relay panel.

Wonder if cleaning the switch contacts on the wand would help?

[Aviator]

Possible broken wiring in the tailgate harness not allowing the wiper park circuit to work properly. Either that or the park circuit in the motor itself is shot.

Dave.

[Willy]

Sorry for not noticing it is about a MY2005, the diagrams are completely useless :o
Apparently Volo started using switches integrated in the modules from 2005.
The CEM label in the diagram is wrong, item 4/58 is the REM. In case of a faulty parking circuit or a wiring
problem with the parking circuit, wouldn't the wiper need to be engaged to get it started in the first place?
Willy

[Leto Atreides II]

Art, I don't think the problem is in the wand. The wiper is always on but the washer is only on if I push the wand in, so the switch there seems fine.

I also tried resetting the REM by unplugging its fuse for a bit, but nothing changed.

I guess the problem must be in the harness or motor itself, as Aviator suggests. How easy is it to get in there and do anything? If it's much of a hassle I'll probably just go without a rear wiper for a while. Leave the fuse unplugged and wait until I have to take it in to a mechanic for something else.

[JRL]

If it functions, it would not be the harness OR the motor.
I have no idea how this system works on a P2, but I would think it's either simple (switch), or more complicated (in the computer system).

Remember the rear wiper swipes automatically if you have the front wipers on and you put the car in reverse.

[Leto Atreides II]

Yah I know about the wiping in reverse. It happens no matter what if the car is in park, reverse, or drive.

[JRL]

Dealer,
I'm stumped

[BillAileo]

My guess is that Aviator is correct: the park circuit stop switch within the motor itself is shot and is no longer turning off the motor.

[JRL]

Well, if you find out it is hardware (motor), call me and I'll get you a used one at wholesale.
(New at wholesale if desired, but used should be just fine and one heck of a lot cheaper)!

[Leto Atreides II]

I guess I will try getting in to the tailgate and opening up the motor to poke around. Any tricks on getting in there or is it fairly straightforward once you remove the 4 screws holding in the tailgate panel?

I may take you up on your used wholesale offer, Jim.

[Leto Atreides II]

Procured myself a copy of VIDA so I think I've got all the documentation I'll ever need. Now to just get time to do it. :)

[dhayner]

The wiring for tailgate items is prone to failure at the tailgate hinge, which causes some problems. I don't know if it could cause yours, but might be worth a check.

[Willy]

Indeed, broken wiring this is a known problem. But as I have mentioned before, looking at the wiring diagram,
I don't think it is possible to bring the wiper in a continous run by either braking wire(s) or connecting broken
wire(s) to the supply voltage in any way order to obtain a continous feed. This is a design strategy specifically
developed to avoid the possibility of components of the car starting a life of their own as result of a wiring problem.
Willy

[robo]

Don't know if you have found anything yet, but before going through the trouble to get access to the motor, I would highly suggest checking the harness near the hinge. It is easier to get at, and I had all kinds of weird things going on with my rear wiper before I fixed this:
http://www.bushkillfarms.com/gallery2/d/1872-1/IMG_0767.jpg

[JRL]

Don't know if you have found anything yet, but before going through the trouble to get access to the motor, I would highly suggest checking the harness near the hinge. It is easier to get at, and I had all kinds of weird things going on with my rear wiper before I fixed this:
http://www.bushkillfarms.com/gallery2/d/1872-1/IMG_0767.jpg

I guess you didn't read the above post, if the harness is bad he would have NO POWER to the motor, thus it could not run at all, much less all the time! :confused:

[Aviator]

I guess you didn't read the above post, if the harness is bad he would have NO POWER to the motor

That would depend on which wires are affected now wouldn't it?!? You're assuming that the whole harness is open.

Dave.

[Leto Atreides II]

I haven't had a chance to look further into it since I last posted... Moved over the holidays and started a new job and we're still living in temporary corporate housing. Once things settle down I'll either try and track it down or give up and hand it over to a mechanic. :)