Wiper motor wiring...not adding up

I just bought a new wiper motor for my '69 CJ-5, and something's wrong. I wired it by matching the colors coming off the switch (red/green/black) to the new motor (exactly the same). All the wiring gauge was identical. I tested the voltage coming off the switch wires to ensure there were no issues...just over 12V from the high and low position (red/green each tested against the black wire, which I'm assuming is the ground, even though on the new motor, the green wire in the connector is a little offest from the red and black ones, so maybe the green is the ground? Anyway, I just matched the colors, since they're all the same and there's no indication on the motor which wire is which.

When I turned it on (before reconnecting the wiper linkage), it went SLOW. And accelerated. In both high and low speed. On one of the settings (don't remember which), it would occasionally skip to high speed and back to low. Then heat started building up in the wires and damaging the wire insulation, with smoke included, so I quickly disconnected the wires.

I tested the resistance between the three wires on the motor. I was getting 1.2-1.3 Ohms from red to green, the same from red to black, and like 0.8 from green to black (I may have switched those around). All my connections were very solid, clean, and new. The wires off the switch were using the male "quick connect" horseshoe-shaped connectors. All of this wire is somewhere around 16 ga., give or take.

Tried connecting them again with the windshield down to relieve some pressure on the wires, which wasn't much, but something I'll have to remedy. Got really solid low and high speeds now. One of the connectors had pulled off, so I reconnected it, got all three back in solid, and tried again. Same slow/acceleration problem again, with wire heat.

Now my resistance from red to green was around 1.2ish still, with infinite on the other two. Reconnected, same problem. Never got any heat on the motor itself, btw. At one point I tested resistance again and got the old numbers, and then retested and got the 1.2 + zero on the other two, and I can't remember what I did in between. I realize that's a little vague, but it's all start to blend together now as I got frustrated.

I just can't seem to see why with good voltage from the switch, good connections (unless those male connectors aren't beefy enough), etc., it wasn't working right, and I can't figure out what could have been different when it started working correctly.

Any help? I'm a bit frustrated, as this is one of the main things preventing me from driving her in the winter.

 

I don't know what the color code is for your motor, but you should be able to figure it out using the manual. I expect it's the same as the '72 wiper motor wiring, described here: http://trailforge.com/TSM/Section_17.pdf - this would imply that red is hot and green and black are your two ground wires. If it's wired like the '72, then you have a wire that is hot all the time, and the two remaining wires are either floating or grounded, depending on the position of the switch. You should not have power "coming from the switch." The switch controls the ground, not the power. Your red power wire should go directly to a fused ignition-on supply of power.

<edit> On second thought, looking at the wiring diagram, the red wire does come from the switch. There should be a circuit breaker on the switch with a lead to the ignition switch, and a socket for your red wire. However, the switch does not switch the hot wire - it's hot all the time that the ignition is on.

The setup is, well, unintuitive. You have a hot wire that supplies juice to the motor all the time. You have two ground wires that are connected to ground through the switch. The manual describes this in the section titled "TWO-SPEED WIPER MOTOR." You should be able to figure it out using the description in the manual and your multimeter. If you have a problem, post back with questions and I'll try to answer.

<also edit> Notice that the park switch (in the motor) grounds through the windshield, so if you have the windshield down and it works, that kinda suggests that you are disconnecting the park switch ground to make it work. Sounds like somehow you have the ground and hot sides reversed?

 

I don't know about the park switch/windshield ground, but I found the culprit. I had put in a temp (SHODDY) ground to troubleshoot, and needless to say, it was less than ideal (and now destroyed, more or less). At least it was my ground wire and not my motor that burned up, although I haven't had a chance to figure out if the motor is salvageable.

I think you're right about the wiring setup, and the fact that it may be reversed. Here's how the PO had it wired:

The black wire--one of the grounds--went straight to ground. Go figure. No switch involved.

The hot wire from the ignition went to the switch, and a red wire and green wire coming from the switch went to the red and green on the motor, respectively, which is obviously wrong. The switch was going between a hot wire and ground. So I guess that I need that hot wire from the ignition connecting to the motor's red wire, and a good ground going to the middle of the switch, with the black and green wires on the switches "output" (or input, depending on the way you think about it)?

 

Also, I'm having hard time finding a good available ground...what's the most ideal solution, normally?

 

Inside the motor housing there is a microswitch (the park switch) that rides against a cam. Only the park switch is grounded through the frame. When the motor is wired correctly, the ground for the motor (both speeds) goes through the switch.

The park switch ground is in parallel with the switched ground. The park switch goes open when the wiper blades are at the "park" position, low on the windshield glass. This means that, when you turn the switch off, the motor keeps running until you reach park and the motor shuts off. You don't need any dedicated ground for the park switch - the ground through the motor body to the windshield frame and then to the Jeep body works fine.

Notice that the two grounds that go to the switch are either used together or only one of them is used. At the switch, the ground goes through the connection on the switch and to the Jeep body through the dash. Again, no real ground wire, other than the connections to the switch.

 

Where is the park switch? Inside the motor?

ALSO...did some troubleshooting...well, started anyway. Took the hot wire and connected it directly to the motor. Switch disconnected, as well as all ground wires pertaining to the motor. I connected a ground wire to an existing ground used by other switches, and I was going to connect the ground to the black and green ground each in turn to test the two speeds. I turned on the key before connecting ANY grounds, and the motor started turning. To reiterate, the ONLY wire on the motor that was connected was the hot wire.

This occured with the windshield both down and up. I tried moving the windshield up and down, and the motor did stop intermittently, but I was never able to make it completely stop by freezing the windshield at one position.

BTW, the linkage is still disconnected, if that makes any difference.

I am thoroughly confused now, lol.

 

Just for further confusion, I decided to connect those other grounds anyway (one at a time) to simulate using the switch. On either ground (with a 12 ga. wire, PLENTY big), the motor operated REALLY slow. At one point it even stopped. No smoke, no heat in the ground wire, just slow then stop. Then I removed the switch grounds and let it use the motor ground again...fast as always. Working like it's supposed to.

What to do? Not like I can go "hot wiring" my wipers every time it starts raining.

 

The 69 - 71 electric wiper system uses a three wire switch and the 72 and up uses a 5 wire switch. If you have a copy of the 1971 edition of SM-1046 there's a very good diagram there and several paragraphs on troubleshooting that switch and motor. Red is high, green is low and black is park. Power from the switch will go lo green or red high as selected. Black goes through the park switch and the motor housing is the ground to the windshield. Try installing a braided ground/bonding strap between the cowl/dash and the windshield.

 

BINGO! Turns out, again, that the PO had the wiring off. This is the switch:

http://www.colehersee.com/home/item/cat/41/59024-15/

Turns out, it's double--not triple--throw...I realized this when I connected the hot wire to each of the three motor wires in turn: Red=fast, green=slow, black=off/park. So I just need a triple-throw switch! PHEW! What ever was happening with the ground was throwing it way off with that super-slow speed.

NOW the question is how to wire the ground (and I still haven't figured out how to route the wires without squashing them under the windshield frame). Can you elaborate on that ground/bonding strap?

For the switch, there's this: http://www.quadratec.com/products/55312_00.htm (and the knob in the lower-right corner?)

Problem is, it doesn't say if it's triple-throw, but it does say it applies to 3-wire motors, so I'm assuming that there are 5 connections for the hot wire, the three motor wires, and the ground to go back to the frame...does this look like what I need? It doesn't even say how the switch operates, I'm assuming it's a rotating switch that needs a knob like the one in the link in the corner?

THANKS for all the help!

 

Those switches are not correct. Take a look at these:
http://www.drivewire.com/vehicle/1969-jeep-cj5/wiper-switch/

They have four terminals as your original should have and they are not including the circuit breaker. So you'll need to supply circuit protection between your power source and the battery terminal. From the 69 to 71 wiring diagram it looks like the original switch was not so simple inside. For Hi it powered only the red wire. For lo it powered only the green wire and for park it simply connected the black park wire to the green lo wire. So these functions aren't available in a standard single throw 3 pole rotary switch. I can't say for sure that the switch you found in Quadratec won't work but I can't say for sure it will. It may be that it will service both early and late systems depending on which terminals you use for which functions.

What drove you to the need for a new switch? Do you know for the condition of the motor and it's brushes?

Do you have SM-1046? If not I Emailed you my email addy.

 

That's a good idea...there are several completely unused bolts across the top of my dash as well; should be a great place for a ground. My main issue is figuring out how to route the motor wires without just drilling a hole under the windshield. The rubber on the bottom of the windshield comes off easily, and I suppose I could just cut a hole in that and drill a hole in the dash underneath; I was just trying to avoid that. I haven't seen the flat "trailer type" connectors at any of my FLAPS.