Wiper Motor Wiring Question

[KVH]

I have a badly fried and melted wire in my wiring harness and it leads to the wiper motor from the wiper switch. I've got the dash off so figure I could check the wiper motor, brushes, etc. My other wiring is terrific.

Can any of you help with these kinds of questions: 1)what can I really check with the wiper motor, and how? 2) three wires come from the motor, one to the fuse box and two to the switch--I'm concerned I might get those other two from the switch "crossed" at the snap connectors and they don't match my wiring diagram colors. Any hints on whether crossing those makes any difference--I think they're just the speed controls, low and high?

(I know that sounds dumb, but this limited area of the car wiring has been worked on by others over the years)

Finally, I'm reluctant to pull apart my entire harness just to add a new bypass wire. I plan to put it in a small diameter harness shield and clip that to the existing harness. Either that, or I could tape it to the outside of the harness, but that would look tacky. Any opinions on that?

(By the way, all of my other wiring appears virtually new. This is by no means a 40-year old harness on my car. Just the wiper motor leads have been monkeyed with, and this single lead wire is fried)

I do have a shop manual for a TR4, but mine is a 4A and the motors and wiring apparently differ.

Any help would be appreciated. thx

 

[Geo Hahn]

This site has a 4A wiring diagram (courtesy of forum member 'danmas') that may help:

https://www.britishv8.org/techhome.htm

If the 4A is harnessed similar to the 4 (but with a 2-speed motor) then the visible portion of the wiper motor harness is just 6" long or so and contains only the wiper motors and a couple of body grounds. I would think this could be fabricated to look pretty good. If 4As used the blue wrap tape (there is so much I do not know about 4As) then this is readily available.

As for 'crossing the wires from the switch" -- I do not know if this would harm anything or just possibly reverse the position of the slow & fast positions on the switch -- best to confirm that before trying if your wire colors are non-original. Bear in mind that like the 1-speed motor, the switch is just providing a ground path for the motor -- the (green) power wire is hot when the ignition is on.

 

[trrdster2000]

I found when someone is having a problem with the wiper switch motor, it generaally happens right after they put in a new rubber hood pin. It goes down just perfect to the wiper blade set switch on top of the motor and shorts out, sometimes a fuse, sometimes a burnt wire, If your adjustment is such you need to get the pin way down, just cut off a little of the threads. Wayne