Some may remember about 3 months ago I posted about the inop exterior mirrors on our "new" 01 S Type. As in TOTALLY dead.

Got into it again yesterday, and much dismantling and careful sleuthing of how things "should" operate. Deemed it to be inside the switch pack.

Had 12v going into the switch pack, so NO broken wires in the door loom to the cabin, GOOD, but somewhere after that it got lost, so nothing coming out of the switch pack to the module, mmmm.

Some dry solder joints on the 26 pin connection to the circuit board, fixed, still dead mirrors, bugga.

Pin #1 is the 12v input, and by tracing the circuit board ribbon, I quickly found that the board is a 2 sided type, so the 12v was going only to the first "hollow tube " that transfers signal from the "A" side of the board to the "B" side, and was "dead" on the "B" side, mmmm.

Using a single strand of copper wire, I joined the "A" side to the "B" side and now I have mirror operation.

The snap shows the "tube" connector that was the cause of all the grief, and it really did take some sorting.

 

I don't see anything burned? Any idea why it just came apart? Does not seem to be very common?
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Agreed.

The circuit board had been looked at and studied by a few "experts" in the field, and they all found nothing wrong.

I had the switch pack out of the door, and from the wiring diagram established (A) how the system works, (B) what wires went where for each requested operation. I had 12v into the plug at pin #1 and all 4 of the "output" wires had 0.006v. Now having NO resistors or suchlike on the board, I then pondered the point: OK got volts TO the #1 pin, but is going any further.

Dismantled the switch a 10th time.

I then began continuity "follow the path" probing, and had path from pin #1 to the "hollow rivet" (where the probe is in the snap) on the input side of the board, with the board inverted, and the corresponding "rivet" probed, ZIP. Looked via a lense from a childs microscope, and I could see "blackish" marks inside this "tube rivet", and basically deemed that this connector had lost its grip on the ribbon track of the board. Carefully scraped back the paint on each side, and threaded a single strand copper wire thru the "tube rivet", and dob soldered on each side. Continuity now flows to ALL points of the window "pad contacts" and the L/R rocker switch.

Voltage path test, SWEET, all as per the wiring diagram.

Plug the sucker in, mirrors WORK, damn I'm good.

Then New Years celebrations were in order, big time, so Canadian Club was consumed in vast quantities, head hurts this morning, who cares the mirrors work FINALLY.

NOT common, agreed again, but I expect nothing less from modern day electronics, every manufacturer is cutting corners, and as long as the item exceeds warranty provision, plus a SMALL consumer consideration, who cares. This car is 10 years old, and since the "average life" of a car from a manufacturers point, is 7 years, it has done well.

 

I think it's a via (Latin for way or path) aka PTH (plated through hole). Shouldn't give trouble but this one did. Well done finding it. Possibly some sort of over-current condition burned it out, though you'd hope a fuse would go instead!

 

Well good job because I would have replaced the whole switch!
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The "blackish" stuff would be indicative of arcing. But that could have been after an initial weakening from physical stress such as delamination or overheat.

 

I believe they are designed to fill with solder during the flow solder process even if they haven't got a component lead poked into them.

 

Can't be sure but looks like hand-soldered.

 

IT IS. I did it as said, and many Canadian Club to steady the hands, trust me.

There are these "hollow" thingies ALL over the board, and they simply pass signal form one side of the board to the other, some have the solder through for items connected, as mentioned, but the others are just hollow, not rocket science now I know, but it did test the brain a tad.