Driver's Mirror Anyone else have this problem?
 

The Driver's Mirror on my 88 cab will only rotate inward when moving the mirror joystick (regardless of which direction the joystick is pushed). The joystick works fine when toggling over to the passenger mirror. Thinking it could be the switch I ordered a new one and installed it yesterday but ended up w/ the same results.

Here is the weird part, if I press the defrost button the driver's mirror rotates outward until the defrost button is deactivated. As this is a cab, the (rear window) defrost button is only used to heat the mirrors. (I live in Phoenix, and I will never need to defrost my mirrors, I just happened to press it, and was surprised to hear the driver's mirror activate). So this tells me the mechanical aspect's of the mirror are functional, but something else is wrong.

I"m fairly positive this is an electrical wiring issue, but was curious if anyone else had this problem and knew a quick somewhat painless fix.

Thanks

Quick and painless are too optomistic. :D

I agree that you have an electrical problem and I would wager it's crossed wiring. I would examine both sides for the connections and compare. Has this car been reapaired in any way?

Milt

Checking the maintenance history of the PO, saw that he had the Newport Porsche dealership look at it and they replaced the outside mirror bushing and noted that mirror was inop and guessed it could possibly be the motor (no further repairs/diagnoses made).

As for any other repair, none that I know of, but I'm the third owner of a 19 year old car, so who know for sure.

As for checking the cross wiring, checking wire at the joystick switch or the mirrors themselves (both, other)?

Thanks for you help.

The fact that your right side works means that the joystick is OK as you proved with the new one. Something is awry between the L/R selector switch and the drivers mirror.

The defroster switch discovery is a good find - either the service dept mixed up the wiring inside your drivers mirror, or it's possible that there are breaks or shorts in the wiring bundle that goes through the left door jamb as both the defroster and motor control wires go through there.

There could also be a short where the wire bundle goes through the door skin to the mirror.

If you can follow the defroster wire from your defroster switch you'll run into the problem sooner or later.

Ron

"There could also be a short where the wire bundle goes through the door skin to the mirror."

I second this. Check for wear of the rubber covering or grommets where the wires pass into the door. I suspect you'll find chafed wires and a couple of places where they could short.

Les

Ron and Les,

Thank you for your tips, I will check it out this week as time permits.

Marco

My 84' Carrera has had this problem in the past. I traced it to a bad ground connection at the ground point located behind the master cylinder(there is a bundle of ground wires attached to a bold braised to the car's body at this point).

Looks like a promising avenue to explore.

Do you have an ohmmeter? Do you have a schematic (Bentley has an abbreviated one.

At the joystick does the (disconected) brown wire at pin 2 go to ground?

Hey gmeteer,

To clarify you had the exact same problem (pressing the defrost button activated the mirror)? And if so when you properly ground it, that resolved the problem?

Thanks and very interested in your reply.

Marco

I still think you have a crossed wire or worn insulation in the bundle that goes to the driver's mirror.

You said that the shop worked on the mirror base. In most cases they have to cut the wires to remove the mirror - or take the time to disassemble the connector pins with a special tool.

Unclamp the mirror base and pull the wires out as far as possible from the door to see if there are splices (and errors.) The other likelihood - as discussed, is where the bundle goes through the door jamb and into the door.

Ron

Marco, my reading comprehension has apparently declined-I overlooked the defrost button issue. However, it still could be the ground wires, and it is relatively easy(and no cost) to remove that one bolt and clean the individual wire connectors that are attached at that position. The ground connections in these cars are notorious for causing weird electrical gremlins from time to time. The usual first thought I used to have when something stopped working was, "aha, I need a new part to fix this", now it's "probably a bad ground.." Crossed wires, like Milt says are possible if some PO has been messing in that circuit, and with the age of these cars anything is possible. Good luck, Glenn

I'm scanning the memory banks to about 20 yr ago, but I seem to remember this happening to an old Jetta of mine. Someone had pushed the mirror all the way to the extent of its travel, which only allowed movement in one direction. I rotated it by hand into a new position and all was fine again. Don't know if this will work for you but it may be worth a try.

Well... do you have a ground going to pin #2 on the switch?

rick-I

No time during the week. Will look to tackle this weekend.

thanks everybody for the tips.

Marco

Ok, removed mirror and sure enough wires had been spliced together. All reconnected wire colors matched, but went ahead and cut control wires and reconnected using non color matching combinations (before inward motion op only and outward when defrost button pressed, inop up or down control). Came up w/ a combination where up and down now work, outward works, but inward inop except if defrost is pressed and then inward works.

Have checked for chaffing at door jam, have found none (not saying there is none, just I haven't found it).

Should I live w/ this completely functional, but quirky operation or should I try something else before soldering and shrink tubing.

PS Can't find my $19.99 pocket radio shack ohm meter (last used to check continuity for the door switches).

Thanks

Is it real hard to get to the switch?

You could restore it to the original condition and jumper the brown wire on pin 2 to chassis.

rick-I,

PMed you.

Marco

Marco:

I suspected the splice work - sorry it wasn't an obvious case of mixed up connections.

Perhaps the advice on grounding issues will do the trick - I don't have any experience there.

If that doesn't cure things and if there are no chaffed wires anywhere, then I would say the problem is at the barrel wiring connector inside the mirror.

As with yours, most people cut the wire bundle when removing the mirrors. But the "official" method is to remove the pins from the barrel connector using a special tool and then pull them out through the base of the mirror. Perhaps at some other point in the past someone did this to yours. Since the wiring colors don't match on both ends of the connector, it's very easy to get it wrong when re-inserting the pins. This could explain why your heater (defrost) switch is hooked to a motor.

I can't find a wiring diagram for the LH mirror, but here are the barrel color connections for a RH mirror - hopefully they are the same on the left. (Pin numbers are stamped on the connector rim)

Function --- Pin# -- Mirror Side Color ----Door Harness Side Color

HeaterA --- 6 --- Brown --- Brown
HeaterB --- 5 --- Brown --- Gray/Green
Common A --- 4 --- Black/Brown --- Red
Up/Down --- 3 --- Black --- Black/Blue
Left/Right --- 2 --- White/Brown --- Blue/Gray
Common B --- 1 --- White --- A) White/Red B) Red

Hope this helps - let me know if you have questions.

Ron

Ron & Rick,

Thank you for your help, but I think I have about pulled my hair out on this one and am ready to throw in the towel.

Rick,

Thanks again for the manual and tried to ground #2 pin but had no affect.

Ron,

Wish I had stopped there....Got the wiring diagram from the manual, colors didn't match and my configuration has one more wire more than the schematic, so found my multimeter and started to check continuity, wires were jumbled from the joystick to the splices, and then jumbled again from the mirror to the splices (7 wires/49 possible configurations). So I pulled the passenger mirror to get the colors of those wires, and these don't match the schematic. I thought let me get the whole picture and pulled the toggle switch (left/right). More wires that didn't match the schematic (expecting 3 wires has 6 instead). Worked up my own diagram from all the known wires and ascertain the proper flow. Too make a long store short ended up w/ mirror operating in same condition as before I started (several hours later- 5 hours to be exact).

I therorize the service tech(s) who worked on this jumbled the wires and tried to rectify it and finally quit when he got it to partially working. Later when the PO reported the mirror was still not working properly a second tech tried his has hand and got the wires further jumbled but this time from the connector. Ugghh.

Anyway, since I have the mirror operating although quirky, I think I'm going to solder tomorrow morning and look for some other project w/ a greater chance of success.

Guys thank you for the advice, and maybe in time I will return to this when I have the door panel off and some time on my hands.

Marco

Just wondering ... did anyone ever find the answer to this mirror problem?