Rear wiper intermittent failure / fuses etc

[BenH]

Hi Folks,

Long time no post, many apologies!

My rear wiper had stopped working in the week, and suddenly started today after prodding around for a bit under the plastic cover. I cleared the washer tube too, which had been blocked for ages. All sorted, or so I thought.

It then stopped again after having turned off the ignition, and turned on again. The fuse was now blown. (15amp, 3rd from left on top row of fuse box).

New fuse fitted, fine and dandy, and then it stopped again after turning the ignition off. Another blown fuse.

All the connections look good at the tailgate end of things, and I cleaned them with WD40 etc.

This wouldn't be a major concern, apart from the fact that the same fuse serves the cooling fan!

Any advice please? An ebay rear washer motor looks nice and cheap, hopefully that might do it.

Cheers,
Ben :):)

[Adam]

Sure its not the cooling fan end blowing the fuse? Might be a funny connection there.

[BenH]

Hi Adam - love the track machine in the other post!

The engine wasn't running during the wiper testing, so I'm confident this isn't to do with it. It had new blue and brown temp senders last year, and I checked the fan operation on Thursday after the wiper motor stopped working, and it was fine.

Incidentally, at this point earlier in the week, when you turned the rear wiper on, there was a distant click towards the rear end of the car, as if the motor was trying to work, or some sort of relay was operating.

The fuse blowing has only started today after clearing the washer pipe blockage and seeing the damn thing working again. Perhaps the boot slamming dislodged something that was sticking in the motor?

Methinks knackered motor to be honest!

(I had a similar issue on the motorbike last summer, where the fan motor would suddenly seize for no apparent reason. We think the windings were collapsing inside, and occasionally making it stick solid. Pop went the fuses there too. Ebay saved the day, as Honda wanted a whopping £200+ for a new motor. Job's a good 'un.)

Cheers,
Ben :)

[Richard]

I would also check the wiring between the tailgate and the body, the rubber boot on the top right of the tailgate when open, as this is common fault where the electrical cables brake and short to the body.
I had this fault on my old brm where the alarm was going off all the time,
checked the wiring and there was a couple of broken cables touching, re-soldered them and problem went away.

[BenH]

Cheers Richard, good info. :)

Does the boot pull clear of the tailgate and body, so you can see inside please?

Ta! :):)

[Richard]

Yes the boot pulls out not much but should be enough.
You will need to undo the electrical tape from one end of the boot, and pull it back on its self (it is tight) and should be able to check for broken wires.

[BenH]

Nice one. :) It's been fine today (kept checking that the rear wiper was working), but I haven't opened the boot yet! Will look at as soon as I get a chance - meanwhile spare fuses and screwdriver are in the glovebox just in case... :):)

[brmatty]

you could always try the MFU self diagnostic test...hold the heated window button ignition off , turn ignition to position 2..relseae heated window button once you hear a beep then all the functions it controls for examlpe rear wiper and lights for example should beep once you try them..if they beep the MFU is ok if they dont then theres more than likely a problem,,,switch ignition off to exit MFU test...

[BenH]

Problem sorted. As Richard said, several wires were cracked around the insulation layer, and the rear wiper power cable (I assume it was the power cable) was snapped by the time it was removed from the rubber boot, so this must have been shorting underneath it all. 20 mins of (very bad) soldering and insulating taping later and it was fixed. :):):)

After many boot openings and closings it still works, although the neighbours must think I'm deranged.

Oh, and reading the fuse box lid inner cover, I think the rear wiper may share the fuse with the cabin cooling fan, not the rad cooling fan, doh! I'll try the cabin fan with the fuse removed just to be sure though. There's a seperate 'cooling fan' fuse on the left of the board which must be the rad fan. Panic over.

Cheers for the diagnostic test info brmatty, I'll have to try that as well just to hear some beeping! :)

And a final thanks to Richard again, really good know-how. :):)