Wiper Switch Wiring

[Stubs68]

Hi all. Been researching the wiper switch wiring topic for a couple of weeks now and although there is allot of good information related to this topic I have not been able to find my answer. So here it goes. I have a 68 W100 with little to no existing wiring. I purchased a American Autowire Power Plus kit. When I got to the wiper switch the kit has one "hot" feed from the fuse panel that is supposed to go to the wiper motor (through the wiper switch). Well apparently they leave it up to the user to figure out the Ma Mopar wiper switch wiring as I have no idea where they want me to connect that wire?

I know the switch is a variable speed switch and it has some sort of grey oblong module on top of the switch that has a orange wire supposedly that controls the back up lights. What is left of the blue wire on the other module terminal may go to the fuse box and I think another wire from the main wiper switch goes to the ignition switch? That's what I know. Anyhow, If I want to retain or recreate all the original wiring with my new harness I need to know what to plug in where. I have attached a picture of the switch below with my questions.

I really would like someone to just draw me a picture or fill in the wires that go to the terminals on my attachment. Please tell me which wires go to what terminals (original wire color would also be helpful).

I would like to keep the original setup with the connections to the ignition and back up lights but if push comes to shove then I may just try to figure out how to get power to the switch and move on. P.S. I don't need the complete wiring diagram for the truck. Have that. Just need the wiper switch drawing and for someone to give me the 4th grade answer as to where all the wires are coming from and going to. Thanks in advance for any suggestions and help. See attachment diagram. Thank You!!!!

[dodgeboykim]

Hot goes to switch yes. But the wiper motor is grounded back through the switch if I remember correctly and the park function is actuated when switch is turned to off. I think 3 wires go from switch to wiper motor.

[pwadventurer]

This wiring is from my 70. it has the 4 wires like yours, might be the same, you'll have to see if the letters on switch match yours.

[Stubs68]

Thanks for the comment pwadventurer. I do not think the letters match my 68 variable speed switch. Everything from the wiper switch to the motor is good. Just trying to confirm where the power comes into switch at. A few have stated that it comes in on the top terminal of the capacitor (fuse). That is where I am now. Thanks again.

[Kaegi]

the grey thing is a circuit breaker. no need to run switch to a fuse panel. breakers are superior to fuses. that is why they use them on airplanes. if you get a short or the motor sarts getting too hot it will click off until you fix the short or motor cools down.

[PwrWgnDrvr]

Thanks for the comment pwadventurer. I do not think the letters match my 68 variable speed switch. Everything from the wiper switch to the motor is good. Just trying to confirm where the power comes into switch at. A few have stated that it comes in on the top terminal of the capacitor (fuse). That is where I am now. Thanks again.

Fuses ARE NOT Capacitors!
What ignorant fool told u that?

[pwadventurer]

This switch looks like yours without the C.B. on the "B" tab. I'm speculating because I don't have the switch in front of me to test, but the "B" tab would be power to the switch. If you want the wipers off with the key, then power comes from a switched source such as the ACC on ignition switch. Get yourself a volt ohm meter and field service manual and test the switches and wiring before turning on.

[Stubs68]

Thanks. I will have some more time this weekend to test this. Appreciate all the feedback!

[Stubs68]

Took another look at the wiper switch today. Hard to tell what the letters on terminals are. However the "B" terminal on your switch looks to either be the circuit breaker on my switch or the terminal hidden behind the female connectors.

See pic below. I am thinking the power is coming from the grey wire at the top of the circuit breaker. This would make sense because I believe that wire came from the ACC on the ignition switch and power would normally run through a fuse or breaker would it not? The 4 wires with female connections all run to the wiper motor.

I suppose a good question for the aftermarket harness manufacture is "if I run a hot lead from the fuse panel directly to the wiper switch as direction by the instructions, is the fuse panel set up to only provide power to the wiper switch when the key is in the accessory position on the ignition switch"?

[dodgeboykim]

Circuit breaker instead of fuse. That's how it was done with those.

[jeffwest]

If your motor is labeled Prestolite 4002, then this information is useful, if another motor, all bets off.

When I got my truck, the wipers were weird, they moved very slowly and sometimes not at all. The park would not work, off was the space between on and off in the switch. Half the time you would have to jiggle the wiper arm to get the motor running. It has recently become the limiting issue to getting the truck finished.

I had bench-tested the motor before and it worked. The bench testing instructions are found in multiple locations on this forum. I was confused when I installed the motor and switch back into the truck and the same outcome as described above resulted. I decided to look at the parking switch, so I pulled the switch and motor again.

After opening the parking switch plate, I noticed the insulation on the wiring going into the motor itself was completely gone in places, allowing multiple bare wires. So I disassembled the unit. After a lot of trial and error, I determined that there was a field coil that would work ONLY in parallel (shunt) with the brushes/armature and the other field coil would work ONLY in series with the brushes/armature. So after a little google, I found some good information via google on an AMC forum. I searched by prestolite 4002 in case anyone wants to go down that route.

The useful piece is the wiring diagram of the switch and motor internals below. This diagram is accurate in every detail that I could validate by actual measurements of continuity. In addition, accomplishing the state described in the diagram results in my motor working perfectly.

In the end, here are the problems found:
-the wiring inside the motor had completely shed the cloth insulation. I put two layers of shrink wrap over every wire in every place accessible.
-there was so much gunk in the brush guides that the brushes would not move without putting a lot of force on them. I cleaned these up and now they move easily.
-the wire to the brushes had broken by the time the motor was disassembled. I had to snip the wire where it entered the field coil package and added a new wire.
-the dark blue to greenish/blue and the black to black connections from the switch to the motor were reversed. My original pictures during disassembly verified this state when I obtained the truck. I had just faithfully used my pictures.

Now the motor has great starting torque and parks nicely, every time. And I finally got time to learn how DC motors work. (I learned that DC motors can be extremely complicated and counter-intuitive to the uninitiated. This motor increases speed by REDUCING voltage to the field coil wired in parallel (shunt) with the brushes/armature.)

I hope this is useful to the community.
jeff

[Kaegi]

Took another look at the wiper switch today. Hard to tell what the letters on terminals are. However the "B" terminal on your switch looks to either be the circuit breaker on my switch or the terminal hidden behind the female connectors.

See pic below. I am thinking the power is coming from the grey wire at the top of the circuit breaker. This would make sense because I believe that wire came from the ACC on the ignition switch and power would normally run through a fuse or breaker would it not? The 4 wires with female connections all run to the wiper motor.

I suppose a good question for the aftermarket harness manufacture is "if I run a hot lead from the fuse panel directly to the wiper switch as direction by the instructions, is the fuse panel set up to only provide power to the wiper switch when the key is in the accessory position on the ignition switch"?

no fuse needed. the circuit breaker is a better set up than a fuse. that's why airplanes run them