Wiper ground wire.

[Ray White]

While I am assembling my TC windscreen I want to take the opportunity to install a new wiper feed. What I would like to know is what I should do about the ground wire?. The wiring diagram shows both wires going directly to the voltage regulator. Is a ground wire running next to the feed inside the frame the preferred option; or can it be attached to the frame itself.?

[Duncan M]

Ray-
The wiper motor is the only instance I can think of in the TC where a "duplex" wiring scheme is used. The positive and the negative wires each have a poly insulation (red and black) and both those wires underneath the poly insulation is a (small gage) solid copper strand, nearly identical to older American house phone lines. The two wires are right next to each other and surrounded by a gray outer insulation. That is how it was originally done. Not much current involved. Very small gauge duplex wire can be a bit tricky to find. As it was a duplex wire, it makes sense to run them both to the voltage regulator, and avoid possible bad grounds.

[Ray White]

Ray-
The wiper motor is the only instance I can think of in the TC where a "duplex" wiring scheme is used. The positive and the negative wires each have a poly insulation (red and black) and both those wires underneath the poly insulation is a (small gage) solid copper strand, nearly identical to older American house phone lines. The two wires are right next to each other and surrounded by a gray outer insulation. That is how it was originally done. Not much current involved. Very small gauge duplex wire can be a bit tricky to find. As it was a duplex wire, it makes sense to run them both to the voltage regulator, and avoid possible bad grounds.

It all sounds like a bit of a faff to me. As I don't like the design of the TC wipers; it is neither safe, efficient or attractive - and as I am intending to use the car rather than show it - I will convert it to a later Lucas DR2 through the scuttle.

[Duncan M]

Take a look at the faff Moss is pushing for the wiper motor wiring.. Should make for a real classy wiring job at the regulator.
https://mossmotors.com/media/instructions/162-020.pdf

[Steve Simmons]

I don't think anyone has a correct looking wire that has the right configuration inside. At least that one will look right I guess.

[Tom Wilson]

Easy to make a good wiper wire with two single strand wires encased in gray heat shrink tubing.

If you use a DR2 wiper motor on the scuttle, how are you going to fold the windscreen down?

[Franz Tenbrock]

thx for this post
now i know why my wiper motor doesn t work
only one wire
i won t drive the car in rain, so in the past it doesn t matter me,
with this information i can solve the next problem of the car

[Ray White]

If you use a DR2 wiper motor on the scuttle, how are you going to fold the windscreen down?

I don't intend doing so ... but the wiper arms could easily be removed if needs be.

[Ray White]

Take a look at the faff Moss is pushing for the wiper motor wiring.. Should make for a real classy wiring job at the regulator.
https://mossmotors.com/media/instructions/162-020.pdf

What a bodge!

If I decide to stick with the usual wiper motor arrangement, I have some grey twin flex that will suffice.

[jddevel]

Does it matter which wire goes to which connection on a TC wiper motor? If so without dismantling the motor which wire goes to which connection as fitted to the screen. Looking at the wiring diagram it looks as if the bottom wire goes to the earth connection on the regulator and the top goes to the A4 connection.

[JonnyP]

Doesn’t matter which wire goes to which terminal.

[Ray White]

I thought this might be of interest. Some people have said that originally the wiper motor wires were grey in colour but I have removed mine and although they appear original they are definitely not grey. The wires have discoloured with age but they would seem to be red; definitely not grey.

[Duncan M]

It was said the outer insulation was grey, Ray.

Here is an example of a "duplex wire" with outer insulation.

[Ray White]

I guess my wiper wires are old but perhaps not original.

[Rob Reilly]

I also am replacing my original wire in my TA, and what came out was two separate cloth covered wires twisted together, no sheath, .039" diameter single strand conductors that certainly appear to be original, tucked in under the rubber channel for the glass.
I found new wire .040" diameter single strand conductor in white and red paired together in a brown sheath, at True Value Hardware, where it is sold as thermostat wire for home furnace systems. It is smaller than the cloth wire pair so should fit nicely in the frame.

[Ray White]

I have settled on grey twin flex wires; I have a reel to hand. . The motor only draws about 2.5 amps so to ensure they would be safe, I bench tested it for 20 minutes and although it became quite warm, the wires remained cool to the touch. Not very scientific I know but if the wires were O.K for table lamps they should be fine operating a 12 volt wiper motor, especially with a separate. low amp fuse.

[jddevel]

One thing I would point out is that as the wire is in an enclosed space in contact with the glass rubber, I suspect heat will not be dissipated in the same way. However I suspect that there will be a cooling factor due to wind against the chrome frame to compensate this.

[joel hutchins]

Hello;
I 'restored' my TC exu starting in 1975 and completing it in 1985, so I have not looked at the wiper wires carefully since then. What I remember is that the wire exited the dash on the left side and went into the vertical post of the windshield near the bottom and then went up and around the corner of the windshield and exited there to attach to the wiper motor. When I go to the shop tomorrow I will check and report if my memory is poorer then I thought.

HUtch