Bench Testing Power Window Motor

[60 T-Bird]

After seeing the price to rebuild and or buy the window motors, I decided to dismantle them myself. I have turned the commutator, scraped out the segments and restored the bushings. No a big deal really. There is a black, green red and yellow wire. To bench test which 2 are for one direction and which other 2 for the opposite direction?

[GTE427]

green - ARM
yellow - DN Field
red - UP Field
black - Ground

Could some one can verify this, I only have a poor resolution scan at the moment.

[simplyconnected]

Here's the link:

http://squarebirds.org/Diagrams-Schematics/1958-1966_Wiring_Diagrams/3WD-418.jpg

[60 T-Bird]

Ya...I got all that but not sure how to hook it up. To say black is ground, I think they mean negative or battery minus. There is no real ground on DC. Where would the positive go? I don't want to fry it testing it...

[simplyconnected]

Martin, I guess it would be more correct to say our cars have a 'chassis ground'. I know, there is no earth ground, but when Ford connected the negative battery post to the engine block and body, we refer to that side of the power as, 'ground'.

Most automotive electrical devices will be manufactured for, 'neg gnd'. Ford stopped using positive ground in '55.

The diagrams show the black wire comes from the motor, through a circuit breaker and it is connected to the car's body. Let's call this the 'ground' wire. This ground wire should be the LAST wire you connect when testing because:

When current flows through ONE field winding, it creates magnetism in ONE direction. Current flowing through the armature also causes magnetism in ONE direction. If those magnetisms attract, the motor goes clockwise. If they repel, the motor turns counterclockwise.

The motor will go up when you connect the green & red wires to +12, then connect the black to (-) NEG.

The motor will go down when you connect the green & yellow wires to +12, then connect the black to (-) NEG.

When testing, I always err on the side of caution and check all motor leads to the case. Suppose there might be a wiring problem inside the motor. If you kinda scrape the last wire, the black wire, to the negative battery terminal, you should expect to see motor motion. If there is a short, excessive current will produce lots of sparks, but no motor motion.

I hope this helps. - Dave

[60 T-Bird]

The diagrams show the black wire comes from the motor, through a circuit breaker and it is connected to the car's body. Let's call this the 'ground' wire. This ground wire should be the LAST wire you connect when testing because:

When current flows through ONE field winding, it creates magnetism in ONE direction. Current flowing through the armature also causes magnetism in ONE direction. If those magnetisms attract, the motor goes clockwise. If they repel, the motor turns counterclockwise.

The motor will go up when you connect the green & red wires to +12, then connect the black to (-) NEG.

The motor will go down when you connect the green & yellow wires to +12, then connect the black to (-) NEG.



I hope this helps. - Dave

This was very helpful Dave thank you. Strangely enough if the black was connected first, nothing would happen. I rebuilt the first one, now 3 more to go.

[simplyconnected]

Thank You for following my direction, Martin.

This procedure is important. If you do it any other way, you will energize the armature without the field, or you will energize the field without the armature. The window control button brings them both in simultaneously, but doing it without a button is more tricky.

My hat goes off to you for getting into the motors. You're right, there isn't much to them. These motors rarely get used or wear out; therein is the cause of most failure.

Side Note: You guys with convertible or retractable tops need to cycle those relays and buttons, just to 'clean off' the contacts in the switches and relays. Relay logic is very hearty (nearly bulletproof) but the worst recipe for disaster is NON-use. Frequent use will make the system work better as some stuck or dirty contacts tend to free themselves.

Martin, clean the motor insides with degreaser (like contact cleaner) and use light lithium grease in the bearings but do not sand the brushes or commutator segments. If they have a black color, leave it. That is carbon 'lubrication' formed by the brushes. If the commutators have a 'glaze' electricity cannot go through, clean that off. Make sure the brushes move freely, but keep all oils away from them as brushes operate hot, and heat turns oil to gum. - Dave

[Guest]

Be carefull disassembling ...

the motor or you will break the brush holder. the arm. end of the case has to come off first. I was able to repair it with epoxy.

As Dave said, clean well. If memory serves they have oilite bearings which are sorrounded by an absorbent pad which should be re-oiled, just don't get carried away and add a small dab of grease at the bearing on assembly. Just like a starter motor, I chuck up the arm. in a drill press or lathe and lightly clean the commutator with non metallic sand paper. The switches are probably more of an issue than the motors. I think there is a post I did on switch rehab in the tech section. Mike

[Anders]

the motor or you will break the brush holder. the arm. end of the case has to come off first. I was able to repair it with epoxy.

As Dave said, clean well. If memory serves they have oilite bearings which are sorrounded by an absorbent pad which should be re-oiled, just don't get carried away and add a small dab of grease at the bearing on assembly. Just like a starter motor, I chuck up the arm. in a drill press or lathe and lightly clean the commutator with non metallic sand paper. The switches are probably more of an issue than the motors. I think there is a post I did on switch rehab in the tech section. Mike

Bingo!
I have done the same....

[Dakota Boy]

The motors on my rear quarter windows are pretty weak despite my efforts to make the operating mechanisms as perfect as can be (if you recall, I had some fancy brass bushings made for these devils).....but you guys are "speaking in tougues" in the posts above...

[simplyconnected]

...but you guys are "speaking in tougues" in the posts above...

Dakota Boy, thanks for your comment. If you don't understand my explanation, that tells me others probably don't either. Please, let me know what you need clarification on. Sometimes I assume too much. If you notice, the only ones who responded were members who already rebuilt their motors. They speak from past experience, which leaves the novice somewhat in the dark.

Ford window motors are not typical 2-wire motors. They are quite different in their construction and operation. What part should I clarify? - Dave

[60 T-Bird]

Yes...the bushings are cinder bronze with oil. But there would be no effective way of getting oil back into them. I used a light "green" grease. Just enough to assemble. I turned .004" off the commutator and finished with 400 paper. I think it is most important to clean between the segments. They were packed full. Packed like that will not allow a good contact between the commutator and the brush's. Resulting in a slow turning, torqueless motor. JMO

[scumdog]

.

Ford window motors are not typical 2-wire motors. They are quite different in their construction and operation. What part should I clarify? - Dave

Dave, from memory (based on my last power-window problem!!) the window motors seemed to only have three wires,- one for up, one for down and an earth.

[60 T-Bird]

Dave, from memory (based on my last power-window problem!!) the window motors seemed to only have three wires,- one for up, one for down and an earth.

They actually have 4. Black, Green, Red. and Yellow.

[Dakota Boy]

I guess I need to read up on electric motor theory and then just take one apart. It's all that strange terminology that's leaving me in the dust!

My window motors could be described as above: "slow and torqueless". I bet all they need is a good cleaning inside?