Wiper running amuck

[Katman]

I've got a recurring problem with my wipers. I cannnot turn them off. I have to disconnect boththe two wire connector (black and power) and the single light blue wire. I have a 71 monte carlo. In checking the wiring conditions I should get from the switch at the wiper motor, everything is in order with ground on the black lead and open on the light blue lead. When I disconnect the light blue lead from the wiper that should stop the wipers from working.

 

I'm wondering if someone could confirm that by taking off the light blue wire at the wiper motor and checking that the wipers dont work. I'm thinking there is something wrong with the wiper motor, not the switch. I can upload a picture if that helps.

[zmanabba]

I have run in to this with my 70 and it ended up being the wiper motor. David

[stangeba]

Something keeps telling me it's a ground problem. I "think" there is a special "strap" of copper that runs from the wiper motor to a ground (one of the mounting screws) because the motor itself is rubber mounted therefor not grounded. I can't find a good picture, sorry. (I also may be wrong on this whole thing)

Bruce

[Katman]

I looked at this possibility and it appears the wiper motor is grounded. Took reading from wiper body to alternator bracket.

Something keeps telling me it's a ground problem. I "think" there is a special "strap" of copper that runs from the wiper motor to a ground (one of the mounting screws) because the motor itself is rubber mounted therefor not grounded. I can't find a good picture, sorry. (I also may be wrong on this whole thing)

Bruce

[wallaby]

Trying to remember here, but the wiring is kinda weird with the wiper motor... there is a second switch in the motor that keeps the motor running and puts the wipers down in the park position before it shuts off. You can turn off the wipers in any position and they don't simply stop there...

[Katman]

Wallaby, that is an interesting point. I also can't park the wipers whenever this happens. So do you think it is fixable or do I simply replace the wiper unit? It is fairly new - maybe five years old. Been having the problem intermittently for the last two years.

[Toppless72]

The wiper motor is supplied 12 volts via the ignition switch and fuse block. The switch on the dash provides a ground to the motor. The "park" mechanism is a cam operated switch that continues to provide a ground to the motor after the dash switch is turned off. Once the wiper arms reach their "parked" position, the park switch contacts open, removing the ground from the motor which stops. So, for what ever reason, the park switch is not opening.

 

There is a gear box that contains the park cam and switch mechanism. It has a lot of grease in there for the gears. Over time this grease solidifies and can cause the park switch contacts to stick on. If you're mechanically inclined, you may want to open up the gear case, clean out all of the old grease, clean the electrical contacts and apply new grease on the gears. I would recommend White Lithium grease.

[Katman]

I'm pretty mechanically inclined. Is this something I can do with the wiper motor still mounted? Or do I need to remove it first? Anybody ever do this that happens to be going to Carlisle? I could wait - it's only a couple more weeks away.

The wiper motor is supplied 12 volts via the ignition switch and fuse block. The switch on the dash provides a ground to the motor. The "park" mechanism is a cam operated switch that continues to provide a ground to the motor after the dash switch is turned off. Once the wiper arms reach their "parked" position, the park switch contacts open, removing the ground from the motor which stops. So, for what ever reason, the park switch is not opening.

 

There is a gear box that contains the park cam and switch mechanism. It has a lot of grease in there for the gears. Over time this grease solidifies and can cause the park switch contacts to stick on. If you're mechanically inclined, you may want to open up the gear case, clean out all of the old grease, clean the electrical contacts and apply new grease on the gears. I would recommend White Lithium grease.

[Toppless72]

My advice would be to take it off. It's easier to work on it while it's face up on a bench rather than sideways leaning over the fender. It's very easy to get it off.

1. Unplug it from the harness.

2. Remove windshield washer hoses.

3. Remove 3 bolts holding it to the firewall.

4. Pull the motor out about 3~4 inches.

5. Remove the nut holding the wiper transmission arm assembly.

6. Remove the motor assembly to your bench.

 

This procedure should take you about 5 minutes.

[Katman]

OK. Removed the wiper today. I went ahead and put my old one back on and hooked it up. It works fine. Took that one back off and now planning to clean it up, remove all the rattle can black that someone applied to the front side of it and see if it is show worthy after that. I bought this remanuafactured unit from the Parts Place because the black plastic case was cracked and at the time they didn't sell a replacement. But went to their site and they sell that piece now. But I want to fix this one if possible. Can you tell me where these contact are and what I need to do to get at them? You say I get to them from the front side of the wiper assembly?

 

Thanks.

[Katman]

Just to clarify my message above which is a bit mixed up. The old unit with the rattle can spray also had a big hole in the big black plastic case. For those two reasons, I went ahead and had purchased a different unit to put on my Monte when I did all of the engine compartment work going on 8 years ago.

[Katman]

My old wiper cleaned up real good - got all of the rattle can black off of it. Now debating whether to just spray clear as I like the aluminum look. But everytime I've use clear, stuff has rusted anyways.

[VE3HZZ]

My problem was not with the wipers not shutting off, but if I (push in) to use the squirter it squirts, but won't stop even when the wipers STOP and shut off in park the squirter would keep going.. I had to pull the tube out of the resevour and turn the ignition OFF. I don't use the wipers that often, but kinda maddening that they pump keeps running IF I press the wiper switch IN to get them working. If I don't press it in the wipers work fine and stop/park. Even if I hook up the hose. But as soon as I hit the switch to cycle the pump it runs and runs!!! This is a NEW pump that was installed prior to my purchase of the car. I thought it maybe the switch but?? Have not played with that as have other things but reading this thread made me remember about it. Anyone else experienced this or could it be a related issue to what was discussed here??

 

Any advice appreciated...

 

Scott

[Katman]

Scott, it's hard to say if it is the switch or the wiper. Your issue is similar but different. The way I checked my unit out was to find out what conditions should be on the wiper pins in the off, low, and high positions. Then I disconnected the switch from the wiper (all three wires, two connectors) and checked each connector while turning on the ignition and moving the switch from off to low to high. The switch was doing what it was supposed to do.

 

off gnd, batt, open

low gnd, batt, gnd

high open, batt, gnd

 

I have not checked the squirters connector but will do so and report back. I have to paint my old unit and put it back in. When I do that, I'll test the squirters.

[VE3HZZ]

Thanks KAT I must admit I have not really concerned myself with that issue due to other CONCERNS with starter, carb, ignition. Once I get all that straight am going to start on these minor annoyances....the wipers WORK so that is a bonus..LOL

 

Any info appreciate it.

 

Regards

 

Scott

[Toppless72]

Windshield wiper motor testing.

 

The issue of windshield wiper failure or testing has come up here from time to time. The way the switch works and supplies power has been a bit of an enigma to many including me. I’ve been studying this system and thought I would post my findings.

 

Well, the switch supplies no power to the motor. So we’ll start there.

 

First, how to test your W/S wiper motor on the car.

 

If you have windshield washers your motor will have two harness plugs going to it. For now, we’ll be concentrating on the 3 wire motor plug. Fig.1

 

 

Step one as always; insure your W/S wiper fuse is good before performing any further tests.

 

Turn the key to the run position and leave the W/S wiper switch in the off position.

Using a grounded test light at the 3 wire motor plug, insure you have power to the middle wire # 2. This wire is energized when the key is in the on position and is hot at all times while the key is on. If you do not have power here with the key in the on position, trace back all connections to the fuse box. This wire does not go to the W/S wiper switch.

 

Remove the connector from the motor. (IMPORTANT: make the test connections in this order)

Hook a good chassis ground to connectors # 1 and # 3 on the motor.

Hook a jumper supplying 12 volts from the battery to number 2 on the motor. Take care not to ground your 12 volt power source to the other connectors or to the motor housing

 

At this point your motor should be running at the slow speed.

 

Remove the ground wire going to # 3. The motor should run in high speed.

 

Replace the ground to # 3 connector. The motor should return to slow speed again.

 

As it’s running in slow speed, remove the ground to the # 1 connector. The motor should move to the park position.

 

If your motor fails any of these tests you have an issue with the motor and further testing on the motor or replacement is necessary.

 

Next, testing your wiring at the motor.

 

We have tested the power circuit earlier so on to the ground circuit. All these tests should be conducted with the key off.

 

Place the key and W/S wiper switch in the off position.

Using a test light connected to the battery; probe wire # 1. The wire should be open. If you get a ground you most likely have a short to ground along the harness or a faulty switch.

 

Using a test light connected to the battery; probe wire # 3. The wire should be grounded. If you do not get a ground, you have a broken wire, a faulty switch, or the switch is not grounded properly.

 

Place the W/S wiper switch in the low speed position.

Using a test light connected to the battery; probe wire #1 & # 3. The wires should both be grounded. If you do not get a ground at both wires, you have a broken wire, a faulty switch, or the switch is not grounded properly.

 

Move the W/S wiper switch to high speed.

 

Using a test light connected to the battery; probe wire # 1. It should be grounded. If you do not get a ground, you have a broken wire, a faulty switch, or the switch is not grounded properly.

 

This test should be conducted with the key on and the connector attached to the motor.

 

While the W/S wiper switch is still in the high position probe wire #3. It should show a very small amount of power. Your test lamp should be very dim. If you use a VOM to conduct this test you’ll find it has about 3.25 volts. This is the ground signal needed by the electromagnet used to activate the parking pawl after you move the switch to the off position. If there is no power on this wire, the internal resister at the connector is bad or not making contact with the motor case.

 

Testing the W/S wiper switch

 

All of the references to the three connectors coming out of the switch will be made viewing it from the back side, in-car-position. The connector on the right connects to terminal # 1 on the S/W wiper motor. The connector in the middle of the switch connects to terminal # 3 on the W/S wiper motor and, the connector on the left connects to the ground side of the two wire connector for the W/S washer.

 

 

Remove the wire harness plug.

 

Using a test light connected to a 12 volt source probe all 3 connectors starting on the right. This should be your results.

 

Switch position Connector #1 Right Connector #2 Midd. Connector # 3 Left

Off position # 1 Open # 2 Grounded # 3 Open

Low position # 1 Grounded # 2 Grounded # 3 Open

High position # 1 Grounded # 2 Open # 3 Open

 

Depressed washer button

#1 Grounded # 2 Grounded # 3 Grounded while holding the button in only.

 

If any of these tests fail, insure the metal switch mounting bracket is securely contacting ground and re-test. If the second test fails suspect a faulty switch.

 

Next, testing the W/S washer wiring.

 

As from the earlier power tests, you should have power to one side of the 2 wire connection as soon as the key is turned to the run position.

 

While testing the ground side you will need a helper or you’ll have to place your test light so that it can be seen from inside the car.

 

Using a test light connected to the battery; probe the black wire at the two wire connector. When W/S washer button is depressed; you should have a ground. When released there should be no ground.

 

If ground is constant, the W/S wiper switch is faulty or the wire is shorted to ground. A constant ground to this wire will cause the W/S washer pump to function when ever the key and W/S wiper switch is on.

 

This information is based on the 1972 model and I'm just assuming the 1970 and 1971 would be similar.

 

[Ian]

Joe can I create a new page in our tech section with this post and pictures? That is great info!!!

[Sam (Bones)]

this is a nice write-up

 

thank-you!!!!

[Toppless72]

Ian,

 

If you think it would be beneficial to others it’s fine with me. Feel free to edit it as you see fit as I tend to get too wordy at times.

 

JC