LH power mirror only goes Up and to the Right

Hello all my name is: Ian
I have a: 1993 Stealth ES
It has the following issue: My LH power mirror will only go Up and to the right. The RH mirror works fine in all directions. The mirrors are power, not heated.

At the connection E-33 for the mirror on the door, I can measure 12V for up and right but left and down are 0V. I have attached the circuit diagram I have been using to troubleshoot this but I am starting to go bonkers trying to find why I am not getting the voltages for down and left. I have tried replacing the switch but the problem persists.

Your help is greatly appreciated as this is the last electrical problem I need to solve before I can focus on the body work and get the car inspected.

Hi , after a quick look I would suspect a broken wire within the harness which joins the mirror switch to the mirror. I would check for continuity of the Y-L wire but you might as well check the other wires whilst you are there. Put your multimeter on ohms and check that the cables are not showing an open circuit. The connector pins maybe bent or giving a poor contact but your meter should pick this up.

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Thanks for the reply.

I tested Y-L and G-L this morning. With the key off when operating down and left I get continuity 10-20 ohms. When operating up and right I get nothing- open circuit which is weird because those are the directions that work.

I’m stuck at work right now but my next go is going to be to disconnect E-32 and see what I got for values there on pins 9, 8 and 7.

A good clean wire should give about 0.5 ohms … an open circuit would just show a 1 on the meter. A very good connection would be close to zero ohms. Have you tried putting a voltage across each motor to check that one of them hasn’t burnt out ?

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I had a similar issue to this, and what it turned out to be was the switch contacts had coroded, maybe worth a check?

Dismantle the switch then clean / polish all the contacts compleatly then apply a thin thin smere of conductive grease (i used vasline)

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Thanks for the suggestions. Tonight I made sure the switch is clean and is making good contact. I took the RH mirror off to check the values there and with battery connected and key in ACC I get voltages for all 4 directions +12V and -12V for forward and backward in each direction.

On the LH side I took the motor assembly out so I could measure right at the wire terminals that would connect to the motors and I still get continuity for left and down when it looks like I should be getting the inverse voltage I am seeing for up and right.

I have a day off on Monday so it looks like I’m going to be visually checking the entire harness then. I’ll report back what I find.

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As far as I can see, the problem can only be caused by a faulty switch because the left/right motion share the same pair of wires as does the up/down motion. If any wire in the loom was broken, the motor for that respective action could not move in either direction. The direction change occurs because the polarity is changed and the polarity change is done solely by the switch.
The only other, but highly unlikely possibility, is that there is some sort of gearing fault on 2 separate motors.
You can easily connect a battery to each motor to test it and reverse the wires to check the opposite direction.

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This would indicate that the replacement switch has exactly the same fault as the original. Quite possible. Bit of a puzzle this one

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I think I have found the problem. It looks like there was a repair to harness E-32 and pins 7 and 9 on it got swapped. I have continuity from pin 7 on D-39 to pin 7 on E-32 when that should be pin 9 on E-32.

I am going to try and fix this tonight and will report back if that fixes it. Hopefully won’t take too long as I have the fender off already.

Edit: I have it all working now. I was wrong. Pin 7 from D-39 was actually connected to pin 4 on E-32. Re pinned the offending wire and now the motors move in both directions.

Serves me right for assuming that the harness would have been repaired properly before given the absolute state of the wiring in the rest of the car.

Thank you again for the assistance everyone.

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The bonus is you’ve got a spare switch :grinning:

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