Mirror Motor- How to test ?

[barlowdo]

I am trying to test a Flag style 911 mirror that I bought used.
I have disassembled the mirror and want to know how to test the motor drive section. I have applied 12 volts to the leads going to the motor but do not even hear a hum. I have also applied 12 volts to the braking solonoid and do not hear as much as a click. Is the motor dead or am I doing something wrong ?

Note: The 911 I am putting this on is an older model and was not equipt for electric mirrors or I would have just plugged it in.

Thanks for any help.

[barlowdo]

Since I have gotten no replies on this one maybe I am confusing everyone. What I did was buy a drivers side motorised mirror at Hershey Swap meet for a reasonable price. My goal is to replace the aftermarket non electrical mirrors that are presently on my car with OEM 911 motorised mirrors . To that end I need to do some wiring and establish that I indeed have a working mirror. I attempted to power the mirror on the bench when the mirror was assembled. But had no luck. So than I took the mirror apart based on info I gained from this B Board for which I would like to thank everyone.

After taking the mirror apart I observed that the previous person placed the color coded wires into the wrong pins after the last mirror removal. I based this on a wiring diagram in my Haynes manual.

I than pulled the plug apart. I first measured resistance across the motor leads and determined that the windings were not opened. However the windings could still be shorted or the motor could be stalled. I then applied 12 volts directly to what I believe is the motor winding inputs. Upon application of power I could not hear a hum or detect any kind of mirror base movement.

Consequently my guess is the motor is bad, But not having a known working motor to test against it is very possible that I am just doing something wrong.

So if any of you out there have been able to make the motor drive respond by applying power to the motor leads or whatever combo of motor leads and braking solonoid is required, I would appreciate your inputs.

[MTH]

Barlow,
From your thread it seems like you tested it correctly. But just in case, you should have 6 wires to the plug. Two wires are to the heater, so you can ignore them. Two wires each go to the motor and the clutch. If I remember correctly, a white and a brown wire go to the clutch. The motor wires are black/yellow and black/violet (?). Ground one of the motor wires and put 12 Volts on the other. It should move (if it's not broken, that is). Reverse the ground and voltage and it should move the other direction. For side to side (or up/down, I can't remember), ground the brown wire and apply 12V to the white (you will hear the clutch ingage) while performing the above with the motor wires.
That should tell you if the motor is working.
Mike

[barlowdo]

Mike , Thanks for the reply, I will verify the wiring on mine.

Don

[barlowdo]

Mike,

I have gotten a little further with how to test the mirror motor.

I purchased a 2nd mirror and went thru the same steps as with the previous mirror. I found that with this 2nd mirror if I applied 12 volts to the blue and black lead that the motor would move the mirror to the left and if I reversed the polarity the motor would drive the mirror to the right.

So at least I was getting somewhere with this 2nd mirror.

But.. when I applied 12 volts to the (brown/yellow striped) and white wires whcih I believe go to the clutch all I get is sparks and the power supply acts to be under a load like leads are shorting out the supply.

Am I suppose to supply voltage to the motor and the clutch at the same time ? Or do I have a bad "shorted" out clutch ?

Thanks for any additional assistance,

Don

[MTH]

Don,
The clutch will only work one way. Ground the brown wire and apply 12V to the white. That should engage the clutch (you'll hear it click in). If you apply 12V to the brown, it won't work (sparks?).
After the clutch is engaged, apply the voltage and ground just as you did on the 2nd motor. That should get it to move up/down.

The clutch on mine didn't engage every time, it would just click and spin. I was going to try and fix it, but I got a good deal on a pair of '86-'89 flag mirrors, so its in a box now.

Good luck,
Mike

[Early_S_Man]

This diagram might help ...

[barlowdo]

Actually I applied 12 volts to brown and grounded white and got sparks.

Than I applied ground to the brown wire and 12 volts to the white wire and got sparks.

But than it is possible that the clutch draws more current than I expected and just applying small alligator clips to pin 5 and pin 6 was to narrow a gap and was causing the spark jump.

I will see if I can get a better connection tonight by grounding the brown wire and apply 12V to the white.



Thanks for the help Mike and thanks for the diagram Warren.

-Don

[barlowdo]

Status:

I applied power to clutch with long extension wires to keep leads far apart and sparks flew immediately. I believe the clutch is shorted out. I measured 18 ohms with my multimeter across the leads of the clutch.

At this point I am thinking about drilling out the pop rivets on the first mirror which has the motor which won't work. I don't feel I have anything to lose since it doesn't work anyway. I hear I will be opening up a Pandoras box with all the cables and such inside. But at least I am not destroying a good mirror motor assembly.

Don

[weber92037]

Quick question for all the mirror experts. I have an 87 Carrera and both right and left electric mirrors will go up and down but will not go in/out. Replaced switch with no results. How can I remove the glass mirror to get at the motor to check? Thanks.

[Glasgow 911SC]

Weber92037, check this.

[MTH]

Weber92037,
the 87-89 mirrors are a bit different from the 86 and older ones. Tilt the mirror up and you should be able to see a black plastic tab sticking out below the mirror. Turn it and the mirror should come out.
But, if both mirrors behave the same way, it's probably the switch itself causing the problem. Check out the Pelican schematic page for the double mirror setup.
Mike

[weber92037]

Thanks for all the tips. The 87 mirror is held on by a ring. There is an access hole at the bottom of the mirror but I found it easier to tilt the mirror all the way down and turn the plastic ring with a screwdriver. The ring will turn counterclokwise about 1/4 to 1/2 inch, then the mirror can be pulled out easily. When replacing, turn the ring clockwise. I tested the motors and have no power to the motor which control the in/out movement. The switch is new (I have a perfectly good switch if anyone needs one). I want to check the power at the selector switch on the dash by haven't figured out how to remove it. Does it pull out or pry out? Thanks.

[barlowdo]

First of all I am glad someone else is attempting to repair their mirrors.

I received an email from the previous owner of the flag mirror motor assembly I have been attempting to test, and he says indeed the mirror worked when he took it off the car but infact it had been sitting around for quite awhile before he sold it to me.

Anyway it is possible that his interpretation of "working " applied only to the left/right movement which the tested and working motor on my mirror validates. But the up/down which doesn't work could be caused by the clutch that I believe is shorted out.

Just for the sake of clarity it is pin 5 that I put the negative lead of my charger on and pin 6 that I apply + 12 volts to and all I get is a bad sparking condition indicitive of a shorted condition. Are these the correct pins to apply 12 volts to to hear the clutch engaging as mention in above posts ?

I am thinking about taking this mirror motor assembly to someone in the local area who has worked with these mirrors just to get a 2nd opinion.

-Don

[weber92037]

Don, can you apply voltage to the two motors in the mirror and check functionality at that point?

[barlowdo]

Chuck,

As far as I can tell, I have one motor and one clutch brake hidden inside each mirror "motor" assembly. Each one has two wires going to it. Looking at the diagram shown above the clutch is pins 5 and 6 and the motor is pins 1 and 2. If I apply power to 1 and 2 the motor will drive the mirror to the right. If I swap the leads the motor will drive the mirror to the left.

If I apply power to pins 5 and 6 with 6(brown wire) connected to the negative terminal of my battery charger as Mike suggests and 5 connected to the + 12 v terminal of my battery charger all I get are extreme sparks. Reversing the leads also causes extreme sparks. I hear no clicking of the brake clutch.

I am told that if I drill out the pop rivets I will find a cable driven control system to get the 4 axis of movment of the mirror. I assume that the clutch some how works in conjunction with the cable to translate the direction of the motor to drive the mirror along the other axis. I have not yet torn one apart as I am told it is messy.

-Don

[Glasgow 911SC]

When I first got my car, the heating element wires were plugged into the motor. The mirror only moved 1 direction and when the heated window was on. I rearanged the wiring but the mirrors dont work (heat does though). I have since tried to test the motor by applying a voltage but with no success. Maybe you could hook the faulty motor mirror to your heater element wires.

And if that works, you could come over here and fix mine.

[barlowdo]

Chris, I guess anything is worth a try !! Have not been to Scotland. Closest I got was probably Newmarket in England. Not too many Porsches but plenty of Mini Coopers and Escorts. This was in the 80's.

I have found that going by the wire color on these mirrors can get confusing as the wire colors on either side of a plug don't match.

The one mirror I got- I have two- someone did the right thing and removed the pins instead of cutting the wires. That was the good thing. But... than they repinned it with all the pins in the wrong holes. It may be what killed the first mirror. The pin numbers are very hard to read.

-Don

[barlowdo]

Success at last !!

A friend of mine shipped me two untested motor mirror assemblies that he had no use for.

One was the bayonet style of which I already have two questionable ones.

He also sent me one ring style.

I applied power to the bayonet style as outlined in the above posts, and surprise surprise it works !! If I apply power just to the mirror motor it moves horizontally, if I at the same time I also apply 12 volts to the clutch, the mirror mount moves vertically.


So.. this tells me that I of my two other bayonet mirror motor assemblies, one is completely dead and the other has a working motor but a dead shorted clutch.

I will tear one of these apart as soon as I finish fixing the oil leaks under my 911 and see how they have gone bad.

By the way, I also found a great way to solve the oil leaks on my garage floor. "Drain the oil out of the car". My floor has never looked better !!

And back to the mirror subject. I see that the ring style uses a completely different motor design more like what I was expecting to see the first time I took a flag mirror apart. It looks to use two gear driven motors instead of the clutch, motor, cable assembly of the other style.

I find it interesting that the two are interchangeable .

Don

[1980SC]

That's some handy information you've gathered Don. My mirrors just move up/down regardless of which way I move the mirror lever. Could just be the little joystick is bad...

Rob
1980sc