Rear window washer pump stuck on... - Page 2

CapeX5 · #11 01-10-2016, 05:21 PM

Quote:

Originally Posted by mcurcio1989

Reviving an old thread here.

So the only solution to the rear window pump stuck on and rear wiper not working is to replace the motor?

It was a little snowy this morning and when I switched my rear wiper on and it was stuck, I went back to free it but forgot to flip it off first. I freed it up and it cycled once and when it did the washer pump was stuck on. Won't wipe anymore and I had to unplug the pump to shut it off. There was a fuse (41) in the glovebox that said it was the rear window washer pump but that did nothing.

The rear motor is somewhat pricey and this seems bizarre so it would be nice to have some confirmation on this before I order one. Also it seems insane that this would cause the bots to blow rather than the fuse. That is very poor engineering. Thanks

Sir, I just had a very similar problem last week with our first snow. Same scenario as you. But, since buying the X I couldn't get the rear washer to work. I tested everything and even replaced the wiper stalk. No change. So, now that the wiper quit, I took it apart and found that something on the circuit board had quit. I was able to jump the contacts on the motor directly and it worked fine. Go through the board, no go. I ordered a used one on Ebay for $100. Will arrive next week. Will post back here to report the outcome. And, I agree, totally piss poor design.

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David.X5 · #12 01-10-2016, 05:50 PM

I'm just lurking, but am confused. Are you talking about a board in the rear wiper motor that controls the rear washer pump or a board inside the rear washer pump (mounted on the washer reservoir under the hood)?

CapeX5 · #13 01-10-2016, 05:54 PM

There is a small board within the wiper motor in the hatch. Once you remove the motor(3 bolts and it drops on your face like it did on me) there is a little black plastic cover where the main wiring connector hooks up. Under that cover is the circuit board. Mine actually has a hole in one of the main chips. Like a burn hole or something. Wish I knew about electronics, I am sure it would be a simple fix. Hoping that a new motor for me will resolve the rear washer/sprayer not working as well.

David.X5 · #14 01-10-2016, 06:13 PM

Thanks. I get it know.

wpoll · #15 01-10-2016, 08:54 PM

When integrated circuits ("chips") fail explosively, blowing a hole in the top of the plastic encapsulation, it's usually due to excessive current and very rapid overheating. Clearly, in this design, the fuse protecting the circuit is either too high in rating or the fault current is taking a path not protected by the fuse. Either way, the design is clearly lacking but I guess the designers can't anticipate every possible failure mode.

If anyone has one of these units (that still works) open, a good close-up photo of the board would be good to help us identify the "chips" so that replacement/repair can be attempted. Once the "chip" has a hole in it, the label is gone...

CapeX5 · #16 01-10-2016, 10:17 PM

Quote:

Originally Posted by wpoll

When integrated circuits ("chips") fail explosively, blowing a hole in the top of the plastic encapsulation, it's usually due to excessive current and very rapid overheating. Clearly, in this design, the fuse protecting the circuit is either too high in rating or the fault current is taking a path not protected by the fuse. Either way, the design is clearly lacking but I guess the designers can't anticipate every possible failure mode.

If anyone has one of these units (that still works) open, a good close-up photo of the board would be good to help us identify the "chips" so that replacement/repair can be attempted. Once the "chip" has a hole in it, the label is gone...

I will take a picture of mine and post it here for others reference.

David.X5 · #17 01-10-2016, 10:53 PM

whadaya mean? you don't have one on your kitchen counter to take pictures of? Next you'll be saying you took the wheels off your house!

wpoll · #18 01-10-2016, 11:33 PM

Well done chaps.

I'm guessing the "chip" that explodes is the MC33286DW - this is a electronic switching integrated circuit - the spec sheet states: -

"This device is a dual high side power switch dedicated for automotive applications. In comparison with mechanical relays, this device offers higher reliability as well as protection and diagnostic features."

Not so much, I guess!

Now that I know what I'm looking at/for, I found this: -

eekkk...

The "chip" is available, even on eBay, so assuming there is little other damage, and the cause of the high current fault is found and eliminated, then a repair is possible. And it's rather cheap!

mcurcio1989 · #19 01-11-2016, 10:30 AM

^ wow much thanks for your input on this! I will have to take mine apart and see if this is the case. If so I think it would be worth it ($8 shipped) to try soldering in a new chip.

There are a lot of situations where I buy into the not being able to predict every failure mode but this is not one. If you are designing any system with electrical motors at least one of the primary concerns with fusing should be preventing the circuitry from locked rotor current in some manner. Its like they never even tested them. That should be the first test they run.

CapeX5 · #20 01-11-2016, 01:53 PM

So, here is my part of the saga. As I said before, I found what I assumed was the fault, just went to Ebay, bought a used one from what appeared a reputable seller. They said it worked when it was removed, blah blah. I get it today, plug it in, no f'n go. After removing it and taking the cover off, here is what I see
The other pic is the 2 circuit boards side by side. In the upper board you see what appears to be a hole in the chip. In the lower it is really cooked. Same frigging problem. I don't know if I have the patience/skill to solder such small joints, but am considering trying it. Can't believe we all have this issue. I would be appalled as a company if I saw this. No excuse

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