Intermittent wiper switch for classic car

[bigpapanoodle]

My old classic only has a one-speed wiper. I really would like to fit an intermittent device so that I can vary the time between wipes. I am fed up with reaching for the wiper switch when there is only very light rainfall.
Whilst at a steam rally recently, I picked up an old wiper dwell switch with a variable dial on the front and I wonder if that will do the job. It has three wires....red, green and black.
I attach a wiring diagram of the present arrangement. There are three wires...green, black and black/green. I would be grateful if somebody would help me with the proper connections.

 

[SparkyChick]

Any chance of some pictures of the wiper dwell switch? Outside and inside?

 

[sean_ork]

Assuming the wipers are already self parking, why not just fit one of the numerous electronic controllers which are designed exactly for folks like you.

Here's just one ....
Variable Speed Intermittent Windscreen Wiper Controller | Smart Kit 1093 - https://www.quasarelectronics.co.uk/Item/smart-kit-1093-intermittent-windscreen-wiper-controller

 

[ruston]

^^^^^ That will probably be your easiest solution , and more felxible in operation.

 

[Auto Technician]

I was going to say fit a rain pilot but was beaten to it

 

[bigpapanoodle]

Photos attached. I have considered the quasar electronics solution but being an old skinflint I am hoping my 50p purchase will work!

 

[Specialist]

Hi: On your diagram, where does the green wire to your wiper motor go ?

On your dwell pot I would imagine that the Red is +12v supply, Black is your Negative connection and Green is the variable output to your wiper motor. You need to check this though.

 

[bigpapanoodle]

Hi: The green wire to the wiper motor is power from the battery. Car is now negative earth (converted)
I guess I could rig up a dummy set-up using a spare battery and light bulb

 

[Specialist]

If the Green is permanent +12v then in theory that would be removed from the motor & go to Red on the Dwell pot, Black would go to the wiper motor side of the wiper switch & Green would go to the wiper motor.
In theory that would give you on / off as normal and variable speed through the pot on the PCB.

As you said, you could check wiring & operation with a battery and bulb or 12v test lamp.

 

[Squid]

Just being nosey what car do you have?

 

[bigpapanoodle]

1963 Trumph TR4