1977 Gran Fury wiper woes

[Manfred1]

Ok I'm trying to figure out a mild electrical fire that may be the result of a bad decision. Its a 3 speed wiper motor and when I got the car 10 years ago they did not work. The switch has a strange "Borg" looking ( heat sink?) that sits ontop of the switch. Its a rectangular block with a few thin wires going into the switch. So, I replaced the non working switch years back with a junkyard one that was identical. Viola!! They worked although it was touchy ( had to tap the switch just right) and only 2 of the speeds functioned, plus it had difficulty "parking". A month back they switch would no longer park and only barely worked with a wipe or 2 before freezing up. So...I di through my stash and find a switch w/o the "Borg" box ( a 2 speed switch I presume), it plugged in the same and the wipers promptly parked. It was dry out so I did not run it through its paces. Drove it for 2 days, all good and then the blue/pink wire caught fire and scared me 1/2 to death. This car is my daily driver. I checked the plug and the "hot' wire was still hot, no fuse blown. The blue/pink is a 'delivery" wire. Of course this wire is deeply embodied in the harness so I'm going to build a new sub harness so no stress is put on the main.

Could the install of a 2 speed switch on a 3 speed motor cause this? Is all grounding through the switch body? What is the "Borg" rectangular box ontop of the 3 speed switch ? Can I trust the wiper motor? Blue/pink wire function? The rest of the sub harness is all good?

Thanks in advance

 

[1970FuryConv]

Ok I'm trying to figure out a mild electrical fire that may be the result of a bad decision. Its a 3 speed wiper motor and when I got the car 10 years ago they did not work. The switch has a strange "Borg" looking ( heat sink?) that sits ontop of the switch. Its a rectangular block with a few thin wires going into the switch. So, I replaced the non working switch years back with a junkyard one that was identical. Viola!! They worked although it was touchy ( had to tap the switch just right) and only 2 of the speeds functioned, plus it had difficulty "parking". A month back they switch would no longer park and only barely worked with a wipe or 2 before freezing up. So...I di through my stash and find a switch w/o the "Borg" box ( a 2 speed switch I presume), it plugged in the same and the wipers promptly parked. It was dry out so I did not run it through its paces. Drove it for 2 days, all good and then the blue/pink wire caught fire and scared me 1/2 to death. This car is my daily driver. I checked the plug and the "hot' wire was still hot, no fuse blown. The blue/pink is a 'delivery" wire. Of course this wire is deeply embodied in the harness so I'm going to build a new sub harness so no stress is put on the main.

Could the install of a 2 speed switch on a 3 speed motor cause this? Is all grounding through the switch body? What is the "Borg" rectangular box ontop of the 3 speed switch ? Can I trust the wiper motor? Blue/pink wire function? The rest of the sub harness is all good?

Thanks in advance

Probably not a problem with your wiper motor
Check continuity and resistance on every wire in the wiper motor wire harness. In Colorado, when wipers freeze against the windshield, the wiper motor can draw a lot of current to try to break the wipers loose. This burns up your wiring harness from the wiper switch to the wiper motor.
Buy a new switch on eBay. Heavy current draw burns up internals on the switch. The junkyard switch has the same problem because it is from the same location.
Most importantly, break the wipers loose by hand from now on (You probably already know this)

 

[Manfred1]

I already have a NOS switch, the correct version.

Thanks

 

[Manfred1]

I'll try the reroute and new switch this week. I bet the frozen wiper is part of the story, especially with the hidden location that loves to hold ice and water.