TR4/4A Too Many Wires? Wiper Motor

[bammons]

According to the wiring diagram I should have a total of 4 wires coming from the wiper motor assembly. I have 6. What also is hindering me is the color is gone from the wires. So first of all on top of the gear box is a wire which you can see is red but it has been spliced in right at the terminal on top so I don't really know what color it should be and I don't see a connection on the wiring diagram anyways. What is it? Next I have the 3 wires coming from the motor which I can't tell what they are by color either. And there is a additional red wire coming from a terminal that may have a red wire already on it. What is this additional wire which is not on the wiring diagram? I do have the black ground which attaches to the outside cover. I tried to test the motor by using the ground and touching power to each lead but nothing happened. Do I have to jumper the two wires going to the switch (2-speed motor) and then figure out the green (power) input? As you may tell this is not an area I really know much about so simpleton answers please. Bruce

 

[Popeye]

I have four as well. I can't find my wiper motor to compare to yours, but photos show four wires.

 

[DrEntropy]

Bruce, there are a couple writeups on the DR3 wiper motor in the Articles section of the Forum that may shed some light. One has a good diagram of the motor and connections.

 

[TRopic6]

Bruce, Here is a picture of one opened up. There are 3 wires in the black insulation plus a black case ground. Looks like you have those, but someone ran a red wire direct from the top of the dome covering the drive gear. This wire is supposed to go inside the motor through a small hole in the front. The other end of it is actually the orange-ish rubber covered wire with the bare strands sticking out.

An interesting 'modification', but everything is there to fix it back correctly. The article that DrE listed is what I used to rebuild one.

Jeff

 

[bammons]

Jeff - So what I think you are saying is the short red wire I have attached inside the motor should be run to the terminal on the gearbox. That would explain the extra wires. So I will feed the red wire on the gearbox inside the motor and solder it to the terminal and remove the short red wire that is there and coming out with the three wires that are supposed to be there? Bruce

 

[TRopic6]

Yes, but it looks like the insulation deteriorated and caused the PO to run a new wire outside the body. It would accomplish the same end (provide ground for the motor to run to the park position), just not as neatly. Here are some pictures when I took one completely apart for a rebuild to help. You may want to renew the grease in the drive wheel & oil the armature bushings, etc. The red wire on the dome goes into the hole in the motor housing and connects to the red/green wire.

Take pictures of how yours are as its easy to get them mixed up, especially when the fabric insulation wears away. They went to plastic later in production.

Jeff

 

[bammons]

Jeff - It looks like you used new wires in your rebuild (good idea of course). Did you by any chance take a picture of the new colored wires after they were soldered to the terminals? If you did and you could send it I could replace or paint my wires to match so I know what is what. Of course now I know which one is red but the other two I can/t tell as there is no color left. I can use the picture in your previous post as I think I can see the left wire might be brown/green? Anyways thanks to everyone for the help. Bruce

 

[TRopic6]

Actually that's a NOS motor made in '74 that I used for reference. The wires on the inside of the motor had good color cloth insulation, so I swapped each wire around to put the faded end on the inside and the good colors on the outside. You have to move the bullet connectors too, but they're soldered so easy to do. Be sure to fit them into a new black covering before you put the bullets on!

The thing about the DR3A 2-speed is that it always has power on the green wire and the other 2 wires provide ground through the switch. The article explains how it works, because its somewhat counter-intuitive. The two speeds come from One or Both wires getting grounded. One wire is a just a resistance wire, and if it gets grounded without the field winding, it will heat up and let the smoke out of the motor.

Using the picture here, the left wire is Red/Green, then Green, then Brown/Green on the far right. The Red/Green isn't connected in the shot because the red wire from the dome goes there too, after threading through the hole and around the (in-place) field coil. If all is well, you can test by connecting 12V to green and ground to the red/green wire. Slow speed is had by grounding both red/green & brown/green. If your motor has sat around for awhile it could be gummed up with old grease - good opportunity to lub the internals.

Jeff

 

[DrEntropy]

The article explains how it works, because its somewhat counter-intuitive.

There's th' rub. The motor is powered with the switch completing the circuit to ground. Same with the park circuit.

 

[DrEntropy]

Any resolution, Bruce?