Gremlins

[PWB]

Greetings Riviera fans,

 

I seem to have an intermittent issue with my left rear power window.

When I purchased the car, the window would not go down.

Bought a new motor, R&R - worked fine.

I hardly ever drive this car, its got super low mileage and zero rust. Wires and their sheathing are still pliable.  In other words - almost like new.

Few months pass by and again the window locks up again.

I know there is power to motor, I can see the ammeter dropping when I hit the switch. I can hear the very faint click in the motor with each flip.

Take motor out and check it. Works fine out of car. I grease all up. Put another new motor in, anyway.

Nothing binding, dragging or squealing. All seemed right as rain again.

 

A month later again the motor is locked in the full down position.

 

Same observation - amp draw and faint clicking sound with each switch flip. Tried to pry it up. Nada.

 

I replaced several GM motors in other models with never a glitch.

 

Any clues?

 

 

Thanks

 

[KongaMan]

It ain't the motor.

[Seafoam65]

                       You are getting bad motors.......we have to deal with this in my car repair business quite often...very frustrating

I've had as many as five in a row go bad very quickly.The fact that it always works at first tells you all you need to know about the cause.

I detest power windows on old cars.....giant PITA. Pictured below is the permanent solution to  your problem! 

Edited August 15, 2017 by Seafoam65 (see edit history)

[KongaMan]

12 minutes ago, Seafoam65 said:

                       You are getting bad motors.......we have to deal with this in my car repair business quite often...very frustrating

I've had as many as five in a row go bad very quickly.The fact that it always works at first tells you all you need to know about the cause.

 

And the fact that it keeps working out of the car would seem to call for further investigation.

 

If it can't be moved when stuck, and if it works again after removing and reinstalling it, one might suspect that something in the mechanism is binding and that bind is getting knocked loose when the motor is being replaced.

 

Take a good look at the tracks and regulator when it's stuck.  See anything catching?  Push and pull on the guides while trying to move the window. Did you take a good look at the gears to make sure they're not chewed or cocked?  Did you run the window up and down by hand with the motor removed?  Did you make sure the motor has a good ground?  Mechanical systems more often go haywire at the extremes of their travel.  If it repeatedly got stuck randomly (e.g. part way down) there would be a better case for reflexively blaming the motor.

 

BTW, if a motor works one way and not the other, it's usually a very simple fix.

[Seafoam65]

              Yes, it COULD be something else, but not likely. When a window is all the way down and trying to go up, that is when the

motor is under maximum load. My 2000 Grand Prix went through 3 bad motors that all stuck only when the window was all the way down.

I changed brands and that one has worked perfectly for 4 years now.

[PWB]

31 minutes ago, KongaMan said:

 

And the fact that it keeps working out of the car would seem to call for further investigation.

 

If it can't be moved when stuck, and if it works again after removing and reinstalling it, one might suspect that something in the mechanism is binding and that bind is getting knocked loose when the motor is being replaced.

 

Take a good look at the tracks and regulator when it's stuck.  See anything catching?  Push and pull on the guides while trying to move the window. Did you take a good look at the gears to make sure they're not chewed or cocked?  Did you run the window up and down by hand with the motor removed?  Did you make sure the motor has a good ground?  Mechanical systems more often go haywire at the extremes of their travel.  If it repeatedly got stuck randomly (e.g. part way down) there would be a better case for reflexively blaming the motor.

 

BTW, if a motor works one way and not the other, it's usually a very simple fix.

Konga

 

I found no chewed up teeth on either motor nor scissor. The travel has not exceeded any limit. Teeth were engaged well when motor was in. When motor is out all goes up and down fine. The "wheel" in the rail has no flat spots.

Its quite nerve racking....

Edited August 15, 2017 by PWB (see edit history)

[1965rivgs]

1 hour ago, PWB said:

Konga

 

I found no chewed up teeth on either motor nor scissor. The travel has not exceeded any limit. Teeth were engaged well when motor was in. When motor is out all goes up and down fine. The "wheel" in the rail has no flat spots.

Its quite nerve racking....

Before disassembling the mechanism again, while you have access, try wiring the motor directly to battery power thus eliminating the possibility you have a compromised connection in the wiring/controls. I know it seems the motor is pulling amps but perhaps a poor connection is not allowing enough current to overcome the full down position to get the mechanism moving. If you apply power and the motor doesnt move you can try adding a direct connection between the motor itself and ground. Doing this is very little extra work and is at least a place to start to narrow down your problem. You could also try tapping/prying on the mechanism while applying power to check for binding....but be careful!

  Tom

[KongaMan]

Here's something else to try: swap motors between two windows.  If the same motor hangs up elsewhere, there's your answer.  If the new motor hangs up in this window, there's a different answer.

[60FlatTop]

20 hours ago, Seafoam65 said:

I detest power windows on old cars.....giant PITA. Pictured below is the permanent solution to  your problem!

I have two complete sets of Riviera crank windows, one came with the car and a second I picked up on Ebay. Both sets are the variable speed model. I like them a lot.

Bernie

[Scott Mckenzie]

Have you checked the bottom of travel stop?

 

[PWB]

1 hour ago, Scott Mckenzie said:

Have you checked the bottom of travel stop?

 

Yes. It is slightly lower than say - it could be. i.e. the top of the window is 1/4" below the opening full down position.

The bottom travel stop bolt is there and tight.

When I hand force the window up it all works again. No corrosion in the rails. Plenty o grease.

Just BAD geometry in this thing - I guess   ugh  

 

 

 

Edited August 16, 2017 by PWB (see edit history)

[Scott Mckenzie]

I have spent more hours than I care to admit on those windows. Mine came disassembled in a box . My guess is that something is binding along the way. The manual is only somewhat helpful , for me anyway. I ended up loosening all the adjustment bolts and then ran it up and down to see where it bound in a slack situation. I should add that I replaced all the rollers and cad plated the rails so there would be no rust. Keep at it and keep us posted when you have the ah ha ! moment.

[KongaMan]

No doubt the rear windows are a unique challenge.  When you're installing/adjusting them, go slowly.  That is, don't torque down one bolt then move to the next.  Rather, snug them up in sequence, then make a second pass for the final tightening.  When you're adjusting them, make sure that tightening one adjustment doesn't pull another out of whack.  It's easy to get something bent or twisted because something was overtightened.  If you think something may be binding, loosen everything and try it then.

 

As long as you're in there: clean out any old, hard grease.  You aren't doing yourself any favors by leaving it.

 

BTW, you can learn a lot (including some new words) if you pull them out in their entirety for a thorough R&R.

[68RIVGS]

. . . going strictly on memory Paul, but if your window mechanism is the same as '68s there is an arm that has a large pivot point (...near the front of the glass), that can rust and seize, or does not allow the mechanism to pivot freely. That may be the source of your problem, and the motor cannot overcome the resistance necessary to get that large heavy,  front window glass moving.

During my resto I changed out all the non-tinted glass, for date correct, tinted versions from an AC parts car. On both front window glass mechanisms this pivot point was rusted and required freeing up before installation.  A little lubrication of light grade oil on all rollers and pivot points may help?

[EmTee]

Possible stuck brush, bad spot on the commutator or armature?  Maybe removing the motor spins the armature just far enough to work on the bench.  Repeat the bench test 99 more times for the next one, or give it a good smack before taking it out and see what happens...

[jsgun]

On ‎8‎/‎15‎/‎2017 at 3:24 PM, 1965rivgs said:

Before disassembling the mechanism again, while you have access, try wiring the motor directly to battery power thus eliminating the possibility you have a compromised connection in the wiring/controls. I know it seems the motor is pulling amps but perhaps a poor connection is not allowing enough current to overcome the full down position to get the mechanism moving. If you apply power and the motor doesnt move you can try adding a direct connection between the motor itself and ground. Doing this is very little extra work and is at least a place to start to narrow down your problem. You could also try tapping/prying on the mechanism while applying power to check for binding....but be careful!

  Tom

This is what I suspect. The motor isn't getting enough amps because of a partially broken wire, or a weak connection somewhere. Possibly the breaker?