3 speed windshield wiper help

Help
I want to convert my 67 dart to a 3 speed wiper.
I have a complete donor to get parts. Switch plug etc
Im sure this has done before but the search feature is very cumbersome and I didnt find anything
Im hoping its just an extra wire to add from the switch to the firewall.
Anybody do this mod?
Thanks

You need 3 speed motor with pivot arm that is on the motor. The arm is the hard part to find. Plus the switch. It should be all that you need at least on a B body. The harness from the motor is different but harness that you need is soldered to the motor.
I would remove the front cover but watch the clocking and clean out the old lub and put in fresh lub. The old lub gets hard.

If the motor has the white nylon cover on it be very careful it is fragile at this age

I know its not plug and play as the wires on the left bulk head connector need to be moved. I have swapped everything over but for some reason the 2 speed switch has an extra wire going to it

hi

also you may need the link that goes to ds wiper pivot as some 2 and 3 speed ones are diff on a bodys .

ran into this on my 74 dart .

Try looking at the wiring diagrams here http://www.mymopar.com/downloads/1967/67_Dart_Charger_Wiring_Full.pdf

you should be able to find the loose wire. Mopar changed there pin outs in 68 so if you have a later motor its not plug and play. You can change the pin out for whatever motor you have as long as it matches the 67

Thanks
looks like the white wire is used reverse lighting wiring.
Why it goes through the wiper switch ...who knows