Windshield Wiper Switch Ground Wire Question
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From: Ogden, Utah
Windshield Wiper Switch Ground Wire Question
I looked at the AIM for my 74 and do not see a separate ground wire going the the switch housing. However, I have read from Willcox that you need to ground the switch housing. Currently I'm having some issues with my wiper motor and before I dig deeper I just want to make sure I don't need to put a ground wire on my newly installed switch which was replaced during the interior renovation. I don't remember seeing one but then again I may have overlooked it. I never tried the wiper motor when I bought the car so I'm unsure if it ever worked correctly. It is working somewhat but just not correctly. The picture I attached is what I found on the net as a reference.
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From: Kelowna British Columbia
The wiper ground and blower motor ground go together and end up on the motor down by the starter. They should go o n inspection plate boly by starter. Lots of people mistakenly put this ground wire on starter and cause a nasty short
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From: Virginia USA
The problem sometimes is the center console breaks at the top where the plate in your pictures bolts against. This is the ground path for the switch on my '71. There was never a wire like you are showing on a '71. That is a good solution if your console surround is broken.
Look at this picture. On the left is a broken gauge bezel. On the right is a good bezel. The real thin part is where the switch loses ground if both sides are broken. The pate in the picture you posted screws against the top part of the bezel.
Also, even though the WW switch connector is indexed, meaning it can only go on one way (look again at the picture you posted and you can see a post coming out of the switch. Also notice what looks like a tab on the left side of the connector) believe me it can be put on backwards. If it is then the wipers will not work.
Look at this picture. On the left is a broken gauge bezel. On the right is a good bezel. The real thin part is where the switch loses ground if both sides are broken. The pate in the picture you posted screws against the top part of the bezel.
Also, even though the WW switch connector is indexed, meaning it can only go on one way (look again at the picture you posted and you can see a post coming out of the switch. Also notice what looks like a tab on the left side of the connector) believe me it can be put on backwards. If it is then the wipers will not work.
Last edited by theandies; Jul 3, 2017 at 03:40 AM.
Team Owner
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From: Westminster Maryland
Hi JU,
On 74 model year cars the ground connection for the wiper switch is through the bezel.
The ground connection for the wiper motor, (and blower motor), is through a wire connection to the same bell housing bolt that mounts the clip for the battery cable as that cable travels forward to the starter connection. The ground wire is part of the engine harness.
The wiper/blower ground wire has a large diameter connector on it which allows it to be used on the bell housing bolt.
UPC 12 A, Sheet 3.
Regards,
Alan
On 74 model year cars the ground connection for the wiper switch is through the bezel.
The ground connection for the wiper motor, (and blower motor), is through a wire connection to the same bell housing bolt that mounts the clip for the battery cable as that cable travels forward to the starter connection. The ground wire is part of the engine harness.
The wiper/blower ground wire has a large diameter connector on it which allows it to be used on the bell housing bolt.
UPC 12 A, Sheet 3.
Regards,
Alan
Last edited by Alan 71; Jul 3, 2017 at 08:21 AM.
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I just tested my wiper motor and its running in Hi and Lo correctly on the bench. I have a feeling I have a ground issue. I'll see if I can find it. I really wonder if that new switch is the culprit with respect to ground. If someone knows a way to test the switch wires by the firewall with a multimeter for correctness without removing the switch that would be great. The middle yellow wire is obviously 12+ ignition. The outside lugs are ground but need to now how to test those properly using the installed switch.
Last edited by JohnnieUtah; Jul 3, 2017 at 10:22 AM.
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Okay. Pulled right dash off to access switch better. Switch housing tested good for ground. It is installed correctly and not on backwards. When all is connected and I turn the ignition key on and the wiper motor just keeps running at the same speed in all positions of the switch...Off, Lo and Hi. The ground harness wire to bell housing is connected correctly. Do I just need a new wiper motor? Does anyone know how to test the switch output leads? I wonder if the new switch is bad.
Last edited by JohnnieUtah; Jul 3, 2017 at 12:34 PM.
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Sure did. After a few cycles the motor just quits now. Can't restart it. I'm going to the parts store and pick up another wiper motor. They have one in stock. If I have the same problem with that one I'll return it. Then I'll know its something in the wiring. From a wiring standpoint it all looks good though. Maybe its the relay.
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From: Kelowna British Columbia
I would think it is the switch if you tested motor ok on bench as mentioned. These wiper motor switches are garbage. They do come apart. I thought mine was bad so bought a new one and it was worse than the one I had. The two tabs seem to make pressure on the contacts so you can push together to increase or pry apart to reduce. Take it apart and take a look.
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Well the switch tested bad according to the Willcox video. I took the new switch apart and sure enough the friggin' Chinese dude forgot to put a spring under the triangular copper piece inside! I had to find a spring to put in there. And no I didn't loose it. It didn't have one. After trial and error switch worked. All continuity checks are good on the switch but the motor has just had it. It starts sometimes and then goes out. I think I had a double hit problem. Going down to get a new wiper motor now. Crossing my fingers.
Last edited by JohnnieUtah; Jul 3, 2017 at 11:20 PM.
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Just wanted to let everyone know that the remanufactured wiper motor runs great. And now with the new flawed switch having a spring installed the motor functions correctly. So I had a double whammy strike against me. Story of my life LOL. Just so everyone knows, that spring's length is very critical to correct function.