Scott S. Posted October 4, 2024 Posted October 4, 2024 I replaced my wiper motor back in May, and everything seemed good. But the last few weeks it stopped again....... Just the blades though. Squirters still work. Checked the wiring, looked O.K. So I went under the dash to check the harness. It had stumbled before but a tap on the dash brought it back. So while I was under the dash, I wiggled the switch and harness and tapped it again. Took Montelishi out yesterday, tried the switch and the blades don't work again. I'm thinking it's the switch............... An opinions ??? 1 Quote
cny first gen 71 Posted October 4, 2024 Posted October 4, 2024 Is The ground strap on the motor ok? 3 Quote
72 Monte Carlo Posted October 4, 2024 Posted October 4, 2024 You could ohm out the wiring between the switch and the wiper motor and verify all wires have continuity. The switch is most likely a lot cheaper to replace than the wiper motor. 1 Quote
Scott S. Posted October 4, 2024 Author Posted October 4, 2024 30 minutes ago, cny first gen 71 said: Is The ground strap on the motor ok? Yup.... 3 Quote
Scott S. Posted October 4, 2024 Author Posted October 4, 2024 30 minutes ago, 72 Monte Carlo said: You could ohm out the wiring between the switch and the wiper motor and verify all wires have continuity. The switch is most likely a lot cheaper to replace than the wiper motor. Already got the new motor..... Works when I run direct power to it. Just seems that the switch has a mind of it's own. 1 1 Quote
Scott S. Posted October 5, 2024 Author Posted October 5, 2024 GREMLINS..... Took Montelishi out for a run this morning....... Tried the switch.............. And they work !!!! I just don't know. 3 Quote
Jeff Dodson Posted January 5 Posted January 5 Question... mine has a ground wire from the harness going to one of the mounting screws of the wiper switch. Is this suppose to be there?. 1 Quote
Scott S. Posted January 6 Author Posted January 6 Hey Jeff, According to the wiring diagram on site, that ground wire ties into all the other dash devices grounds..... Radio, lighter, etc. I'm thinking it's probably just another one meant to insure a good ground. Is there anywhere else close to it that connects directly to the dash ?? Maybe the previous owner just thought that was an easier place to tie into ? 2 Quote
Jeff Dodson Posted January 6 Posted January 6 4 minutes ago, Scott S. said: Hey Jeff, According to the wiring diagram on site, that ground wire ties into all the other dash devices grounds..... Radio, lighter, etc. I'm thinking it's probably just another one meant to insure a good ground. Is there anywhere else close to it that connects directly to the dash ?? Maybe the previous owner just thought that was an easier place to tie into ? It goes into the main harness. There are 3 coming from the same spot in the harness. 2 that attach to the metal frame of the dash and 1 longer ( one in question ) was attached to the wiper switch. 1 Quote
Scott S. Posted January 6 Author Posted January 6 I know it's a '70 diagram, but it should be similar... If you look at the lower left, you can see that it doesn't show how it's connected to the dash, but it's there... Like I said, maybe the previous owner found it easier to use the switch mounting screw.... I can't remember off hand how mine is attached, but it should do the same job as long as it's a good contact. 2 Quote
Jeff Dodson Posted January 6 Posted January 6 55 minutes ago, Scott S. said: I know it's a '70 diagram, but it should be similar... If you look at the lower left, you can see that it doesn't show how it's connected to the dash, but it's there... Like I said, maybe the previous owner found it easier to use the switch mounting screw.... I can't remember off hand how mine is attached, but it should do the same job as long as it's a good contact. So, I guess the real question is, does the wiper switch need to be grounded since the dash is plastic ? That's the only way I would see it being a functional ground. If something else is grounded through that wire, attaching to a switch that's mounted to plastic is worthless, not grounding anything 1 Quote
1970mcss Posted January 7 Posted January 7 I thought the harness has a ground ring that goes between the wiper switch and the threaded metal nut that holds the switch to the dash bezel. That creates the ground for the wipers. 2 Quote
Jeff Dodson Posted January 7 Posted January 7 33 minutes ago, 1970mcss said: I thought the harness has a ground ring that goes between the wiper switch and the threaded metal nut that holds the switch to the dash bezel. That creates the ground for the wipers. I think you're thinking about the Headlight Switch. 3 Quote
cbolt Posted January 7 Posted January 7 Whenever my wipers act up the first place I check is the wiper transmission. There is a pivot point "ball" that also seems to serve as a ground point, and if it gets corroded at all it makes the wipers not work even when the squirters do. That has happened to me several times and I have never had to replace the switch, which I have every reason to believe is the original. Have you checked that? You can also read the switch out with a multimeter to see if it is functioning properly before you buy one. 3 Quote
stangeba Posted January 7 Posted January 7 I found this picture of the back side of WS Wiper switch from my 71 Monte. I assume the black wire is the ground. 2 Quote
Scott S. Posted January 7 Author Posted January 7 20 hours ago, Jeff Dodson said: So, I guess the real question is, does the wiper switch need to be grounded since the dash is plastic ? That's the only way I would see it being a functional ground. If something else is grounded through that wire, attaching to a switch that's mounted to plastic is worthless, not grounding anything No, the switch isn't grounded to the dash. That's what the black wire between the two blue wires is for. It's more of a redundant ground to the frame. Quote
Scott S. Posted June 30 Author Posted June 30 Finally got it beat !!! Brittle wire at the connector...... Now I can be "Driving in the Rain" again. 2 Quote
GRAY 70 Monte Carlo Posted June 30 Posted June 30 On 1/7/2025 at 8:05 AM, stangeba said: I found this picture of the back side of WS Wiper switch from my 71 Monte. I assume the black wire is the ground. Should have a ground brkt pictured below also has lead that goes to headlight switch 1 Quote
Paul Bell Posted September 7 Posted September 7 Yes, the wiper switch's metal housing must be grounded. It uses the same strap that goes under the headlight shaft nut. For 1972, the harness and switch were improved to have a wired ground to the switch which has an extra ground terminal. In use, the wiper motor and washer pump both get ignition + anytime the key is on via the black/dark blue/yellow wire. While the motor ground is from the motor case to mounting bolt strap, the first ground from the switch triggers the motor out of park and into low speed, the second ground from the switch triggers high speed. When the switch is turned to off, these grounds disappear and the motor cycles into park then off. Pushing the switch in forces it into low speed if it was off and sends a third ground to the washer solenoid to pump washer fluid. A small motor driven pump is available that fits into the stock pump housing which works better than the factory plunger pump. To ensure a better ground at the switch, I soldered a wire to the switch's metal housing. If the motor to mounting bolt ground strap is poor, the low speed resistor will smoke and you'll be off to the store for a new one. The ground strap is critical. I added a ground wire to the motor case. If you buy a rebuilt motor, make sure it has the correct number of terminals, the rubber mounting feet and ground strap before you surrender your core. 3 Quote
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