1969 GTX 2sp Wiper Wiring has no ground.

[Satellite Jerry]

Hi Guys, I know this subject is covered many places and I have read them all and am still confused. I am helping a friend with this project and it came to me not functioning so I am challenged to begin with. The entire wiring system had many issues so we started with complete kit from Ron Francis. We are keeping the car as stock and original looking as possible. It has a 2 speed rocker switch and a 2 speed motor. I have had the switch apart and it functions fine but has no internal provision for a ground. I've had the motor apart and it does have 1 terminal that goes to ground when in the park position. Standard motor test procedures say the motor is fine. When installed on the car and wired like the diagrams the motor starts then stops as soon as it comes off the park position. The motor looks correct but there is no part # on it to confirm. I'm thinking either there is something missing in the wiring or the motor is wrong for the application. The little ground wire in the photo was not hooked up when I got it and creates a short when hooked to the M1 terminal. If anyone has info It would be greatly appreciated.

 

[Nacho-RT74]

Ok, I'm not an expert but

Motor should get a ground strap between one of the mounting nut and the resistor mounting screw

Wiper switch is chassis grounded. Usually they have a prong which is not used once switch is mounted on cluster, but actually gets it by chassis

After this, all the magic it happens internally on switch switching the sources as needed. When in off one of the wires is hot as far ign key is on. This feeds the motor to work the reverse position to make the internal cut off switch lever work.

Wiper motor gets just 4 wires, and one of them making a jumper to the resistor ( brown )

 

[493 Mike]

Just guessing here, the short wire with the female spade looks like a ground connection. I remember the motors having a brass ground strap bolted to one of the mounting studs. That compensated for the rubber mounting insulation.
Mike

 

[Nacho-RT74]

Ground brass strap. Its the only ground provision all around, which is in fact a chassis ground, but since motor gets isolation bushings to absorb the move, its needed for the motor chassis

 

[Nacho-RT74]

As mentioned, on parking position one of the wires remains hot ( I think is the blue one ) while other one becomes on ground from ign switch to make work the motor in reverse speed up to the point the parking lever cut off switch attached to the main gear shaft gets the parking point and cuts the power by itself. In any other position, the ground is just the chassis at motor.

 

[Topher]

2 speed wiper motors do not reverse to park. They work in slow speed until it reaches the position to open the power contact. There are 2 types of 2 speed motors: Concealed and Non Concealed. How did you test the motor? There's 2 different tests for each type.

 

[Nacho-RT74]

Mmmmm actually after disassembly and fix my two speeds motor I found the only way the switch off lever is engaged to the main gear shaft is rotating in reverse.

in fact you can see how the wipers begins an opposite direction move when you turn it off.

Sure mine is for conceleaded wipers

 

[Topher]

Mmmmm actually after disassembly and fix my two speeds motor I found the only way the switch off lever is engaged to the main gear shaft is rotating in reverse.

in fact you can see how the wipers begins an opposite direction move when you turn it off.

Sure mine is for conceleaded wipers

The concealed motors do. I wasn't clear on that. The non concealed motors do not reverse. That's why there's specific tests for each motor.

 

[Nacho-RT74]

I know also concelead wipers needs to rotate oposite to move the parking cam mounted between crank and main link.

soooo if non conceleaded system works diff then is a diff story and I don’t have anything else to add... I think, LOL

 

[Satellite Jerry]

Thanks Nacho & Topher. Now this is starting to make sense. I will include some diagrams to illustrate what I have been doing. My motor must reverse to get to park position. There is no number stamped on the motor so I am guessing on that, but it sounds like I have a regular 2 speed switch and a concealed 2 speed motor. If that is the case that explains the issues. This car was reconstructed from who knows how many cars so a wrong motor does not surprise me. It does look just like the correct one. BTW the motor casing is always insulated from a chassis ground except when in park position. Grounding the motor or switch makes no difference when using the car wiring. Using the bench test procedure it goes fine low & high, and the motor goes reverse rotation till it parks. Sounds like I need to swap motors. Anybody got a suggestion. Thanks again.

 

[Nacho-RT74]

Both, motor and switch needs to be chassis grounded no matter what year, car o system. Then accordingly with the motor and switch setup will respond, but the chassis ground is allways present

 

[Topher]

The switch must be grounded correctly to park. The motor must be grounded to work. If you have a concealed motor, then it is wrong for the car. If you need one, I have some.

 

[Satellite Jerry]

The switch must be grounded correctly to park. The motor must be grounded to work. If you have a concealed motor, then it is wrong for the car. If you need one, I have some.

So it since the motor I have does need polarity reversed to get into the park position, I am assuming it is a concealed motor. If I understand correctly Topher the motors you have do not reverse and would operate when grounded to the chassis and must have an internal position sensor that tells it where to stop for park. If that is correct I think that will solve my issues.

 

[Satellite Jerry]

First I want to THANK the contributors for all the information. Your help lead me to a solution. This was my first project on a 69 so I had a lot to learn. For the benefit of the next person, here is what I found. This GTX had a 6 terminal two speed control switch. The motor, by every visual indication was a stock 2 speed motor. That was what threw me off. Someone had installed a motor that looked exactly correct but was in fact a 2 speed concealed motor from another mopar application. The stock 2 speed non-concealed motor always rotates one direction and stops in its park position via an internal contact. The 2 speed concealed motor looks identical but is different internally. It requires that the input polarity be reversed causing the motor to rotate backward till it reaches the park position. Thus my dash switch and motor were incompatible. Replacing the motor solved my issue. The correct non-concealed motor is always grounded using the copper ground strap under the resister. The switch does not need to be grounded and has no internal ground connection. The concealed motor is internally insulated from the chassis in order for the reverse polarity to not ground out, but it has a ground strap on it and an internal ground connection that grounds to the case when it reaches the park position. It's motor has no chassis ground when in the run position so I (assume) it is grounded through the wiring to the switch when mounted on the proper application. I hope this will help someone in the future. Thanks Jerry