Headlight wiper issues - 04 XC70

[scot850]

I have a problem with having to understand what goes wrong with stuff. For those who don't care if their headlight wipers on their 01-04 P2 work or not then you can stop reading.

Those of us north of the 49th who like the wipers as in winter the headlights can get really dirty, we like working headlight wipers.

OK, our son has an 06 XC70 with the headlight sprayers, but having been working on the 02 Xc70 recently, the new young owner expressed a wish for his to work. So I went to the junkyard (have to remember not to pull these from there again as <$20 you can't return them), and as there were a couple easy to remove from an 04 Xc70 I brought the poos things home (as you do).

I decided after talking to Blacklab247 on the subject (a bit of a passion of his) that I would take then apart and clean and refresh as I have done on P80 units in the past.

I found this YouTube video from a fellow Canuck was helpful:



The usual fight to open the case and hope not to break the multiple plastic tabs in the process. I opened the first unit. The video guy showed the issue with the plastic/nylon large cog wheel which attaches to the wiper arm spindle. The first unit this was totally free to move and no issue, so looked further in. Yikes, the worm drive gear on the motor shaft had stripped. Um, so had the teeth on the gear it attaches to.

Well that unit is junk. Can't return as mentioned above. So thought I'd open the motor to see why it does move. Wow!! It was totally full of carbon brush material. I guess the brushes were done. As was the contact face on the rotor where it fitted to as half of the copper/brass contact surface had disappeared. So the motor is dead as well.

Looked at the 2nd motor. This one the motor works great, but in this case that large gear/cog wheel is almost completely seized to the metal it sits in. I will have to take a dremel to it to widen the surface slightly, or substitute the wheel from the other motor.

At least that one has a potential to work again. I may have to rob parts from the other to make one complete motor.

Interesting process to me to understand how it works and what goes wrong with them.

Inside the headlight wiper motor unit

Close up of the inside

Inside of motor casing

If you look closely at the black worm drive, the center position the ridges are much wider due to being almost worn off in the middle.

motor covered in dirt

Contact surface 50% missing

Gear that contacts motor worm drive

Neil.

[Blacklab467]

I've got a box with at least a dozen of these, both sides. You're welcome to a couple working ones for no charge, I've been hoarding them you might say. I have to come over there next week to clear that Airbag message, got sent to North Carolina all week and just got back.

[scot850]

Much appreciated. If you have a good pair of working ones they would be appreciated. Iw ill try to complete the repairs on the working motor one and if I do give you one back.

Neil.

[cn90]

Yes, I stopped reading after the 1st paragraph.

I decommissioned my system years ago, the ROI (return of investment) is not there for me, and yes I have snow in the winter.

[scot850]

I understand that. They can be more bother than they are worth. However, we get a a lot of chinook winds here which means lots of freeze/thaw cycles which make for constant really dirty headlights. I prefer the wiper version over the spray versions as those use so much fluid to do their work.

Neil.

[scot850]

So one of the wipers works in a fashion, but can't actually test it unless I can figure out how the unit is signaled for each limit. There is a pin on either end of the spindle gear travel. The unit has a 3 wire connector. I will have to see if I can find the wiring diagram for the motor and if there is any info on how it signals the unit. It may be an internal switch that determines that. TB figured out!

Neil.

[Blacklab467]

Yes, I stopped reading after the 1st paragraph.

I decommissioned my system years ago, the ROI (return of investment) is not there for me, and yes I have snow in the winter.

For many climates, these things are of limited use or not useful at all and not particularly helpful in snow but more for dirty, salty slush that accumulates and refreezes, like the conditions that we get here in the winter. I can recall a trip I did to Smithers, BC a few years ago in February on the Icefields Parkway (Hwy 93) at night where the headlight wipers probably saved my life on a two lane road with logging trucks and moose everywhere, and nowhere to stop or pull over for hundreds of kilometres due to snow plow windrows.
Some car owners like myself are also particular and like to have all installed equipment present and functional as the car was designed and delivered. Others are more tolerant with broken or inoperative equipage on their ride, to each his own.

[cn90]

I fix virtually everything but this feature is worthless for me.
From an engineering standpoint, they started with the HL wipers, only to end up with tons of repair issues.
Then they switched to HL washer jets, which consumes a lot of fluid. At one point, I was out of fluid bc of the HL washer jets, it was very dangerous, almost causing accident.
So I decommissioned the system to save fluid.

Every road I drive...there is always a place to pull over to manually clean the HL lens.

[br0dy519]

Best way to decommission ? Tired of wasting fluid myself.

[StickyPocket]

Best way to decommission ? Tired of wasting fluid myself.

Not sure if it's the best way, but I just replaced the first plastic T adapter after the washer pump (that splits towards windshield and headlights) with an I adapter so everything goes towards the windshield.