Passenger Window motor not working (again!)

[greyV8pete]

A problem that I have had before with my Hunter has once again reared its head but all the usual suspects have been addressed to no avail.

Problem previously fixed by:

1) Replacing one of the feeble push on connectors on the back of the switch that had come off when working under the dash on another job. This time all checked and ok.

2) Cleaning the two spade terminals for the window motor connection in the door (the ones that lie in a pool of water in the bottom of the door!). Cleaned and tightened but motor still doesn't turn.

When I press either the down or up switch the voltmeter kicks so it looks as though power is getting to the motor ok. It just doesn’t turn. So it looks as though winter has got inside and siezed it up, or the commutator is covered in dirt etc so a strip down looks like the way to go.

Has anyone stripped down a Hunter / Cabrio window mechanism & motor? I can see that there are three large pop rivets holding the mechanism to the door and some M6 screws holding the mechanism to the door but I would appreciate any hints and tips on this job.

Another thought. How does the motor earth? Is there an earth wire hidden underneath which may be the issue? If the earth is through the door hinges then maybe I will try a temporary wire direct to the motor assembly before stripping down.

Peter.

[chris_cussen]

Re: Passenger Window motor not working (again!)

Hi, The motor is not earthed directly, the up/down switch swaps the positve and negative feeds, since the motor is DC it rotates in one direction when connected one way, and the other when connected the other way.

Have you tried helping the window move by pulling/pushing it in the required direction. Mine was a bit reluctant to move after 2 years un used, but with a small encouragement it seemed to free up.

Another thought, has the window siezed in the runners?


Can't help with the installation as I built my cabrio and used nuts and bolts to locate the motor.

[greyV8pete]

Re: Passenger Window motor not working (again!)

Thanks for the info Chris. Motor is wired as I thought then. Window is free in runners and was working until a couple of weeks ago. Have tried a good thump when the switch was pressed but no go.

Today I will try a 12v (through a fuse!) direct from the battery to each motor terminal in turn. I will also delve behind the dash with my borescope cam to see if I can see any lose wires there. As there is current getting to the motor I suspect that an earth to the switch is poor somewhere. Peter.

[greyV8pete]

Re: Passenger Window motor not working (again!)

Before touching anything today I drove 3 miles to fill up with fuel. When I returned home the window worked perfectly! Most strange.

[greyV8pete]

Re: Passenger Window motor not working (again!)

Thanks for the info Chris. Motor is wired as I thought then. Window is free in runners and was working until a couple of weeks ago. Have tried a good thump when the switch was pressed but no go.

Today I will try a 12v (through a fuse!) direct from the battery to each motor terminal in turn. I will also delve behind the dash with my borescope cam to see if I can see any lose wires there. As there is current getting to the motor I suspect that an earth to the switch is poor somewhere. Peter.

Still pursuing the earthing issue I put an ohmmeter between the near side door and the body and surprise, there was an intermittent reading when I tried to move the door in an up and down direction on its hinges! QED!

As a quick fix I have put an earthing link from the door to the body, cable tied below the door check strap. Result perfect window operation! I will run a permanent wire inside the body-to-door cable duct when the weather is a bit warmer. May also do the off side door too to prevent possible similar problem there in the future. Peter.

[peterboat]

Re: Passenger Window motor not working (again!)

If I had a pound for every jag wiring loom I had repaired at the hinges I would be a very rich man!!

[greyV8pete]

Re: Passenger Window motor not working (again!)

Hi, The motor is not earthed directly, the up/down switch swaps the positve and negative feeds, since the motor is DC it rotates in one direction when connected one way, and the other when connected the other way.

Have you tried helping the window move by pulling/pushing it in the required direction. Mine was a bit reluctant to move after 2 years un used, but with a small encouragement it seemed to free up.

Another thought, has the window siezed in the runners?


Can't help with the installation as I built my cabrio and used nuts and bolts to locate the motor.

Having re-read this post and checked the wiring diagrams for both the Sierra and the Scorpio I agree with the theory. So why does adding the earth wire solve the problem? Maybe when it stops working again I will return to GO, not collect £200 and have another think. Peter.

[Mike]

Re: Passenger Window motor not working (again!)

Having re-read this post and checked the wiring diagrams for both the Sierra and the Scorpio I agree with the theory. So why does adding the earth wire solve the problem? Maybe when it stops working again I will return to GO, not collect £200 and have another think. Peter.

I suspect it tells you a great deal.
The new wire is creating an earth that the original wire is not making. You now know where your fault is.

[greyV8pete]

Re: Passenger Window motor not working (again!)

I suspect it tells you a great deal.
The new wire is creating an earth that the original wire is not making. You now know where your fault is.

Ah but the mystery is that the DC motor only has two wires that the switch changes over to get the up or down window direction. However the switch does have earth wires going to three of the six terminals! Meantime I will drive on until the problem occurs again .

[scott h]

Re: Passenger Window motor not working (again!)

Hi Pete, I think you hit the nail on the head when you earlier said you suspect a poor earth to the switch. Maybe that circuit is not complete some or all of the time. When you apply 12v+ to the motor the electrons will try to return to the battery any way they can. The proper route is by the earth on the switch but if it is not complete perhaps they are returning via the door through the hinges. Witness trailer lights with a similar problem and the electrons find a way back through brake lights for example when you want indicators.

[dave_kitson]

Re: Passenger Window motor not working (again!)

Hi Pete - Two points raised by this thread. (1) There should be a few holes drilled in the bottom of the door to drain any water, as detailed in the build manual (Marlin not following their own instructions?). (2) In view of the current these motors draw they really should be wired through a relay which would help prolong the life of the switch. If you do take the motor out, clean and test on the bench to ensure free running, then any subsequent stiffness is due to installation problems - eg the inner door panel flexing as power is applied. Dave.

[b_caswell]

Re: Passenger Window motor not working (again!)

If the windows not raisin its probably a currant problem but if there is water in the door it wont help old fruit!

[greyV8pete]

Re: Passenger Window motor not working (again!)

Hi Pete - Two points raised by this thread. (1) There should be a few holes drilled in the bottom of the door to drain any water, as detailed in the build manual (Marlin not following their own instructions?). (2) In view of the current these motors draw they really should be wired through a relay which would help prolong the life of the switch. If you do take the motor out, clean and test on the bench to ensure free running, then any subsequent stiffness is due to installation problems - eg the inner door panel flexing as power is applied. Dave.

Hi Dave. Yes I do have holes in the bottom of the door one front and one back to cope with up and down hill parking. Since I added the temporary earth wire so far no problems. Time will tell I guess. Peter.

[greyV8pete]

Re: Passenger Window motor not working (again!)

If the windows not raisin its probably a currant problem but if there is water in the door it wont help old fruit!

OHMG this could get terminally out of hand unless I have the capacity to show some resistance and get it permanently down to earth.

[b_caswell]

Re: Passenger Window motor not working (again!)

Well its not a wind up!!