i am fitting a 3speed wiper motor to replace the 2speed motor in my 1970 barracuda have tested the motor it workes fine have a 3speed switch P/N 2770380 have put in car turned ignition on grounded switch & motor but not working the 2speed motor and 2speed switch work fine but as soon as i put the 3speed motor & 3speed switch in it doesnt work anybodys help in this matter would be much appreciated cheers steve

There was an error in my original '67 Plymouth service manual showing the A-body wiring diagram. The wiring for the wipers going through the bulkhead connector were wrong.True,different year,different car but something to consider.

I think there is a wiring harness difference.

it's not a plug in installation...if it was i would of done it also..the harness has extra wires for the 3spd...u must run those and the wiper transmission is different also..check a wiring diagraghm and add the extra wires...

The wiring is identical. Is the switch good? As stated above the transmission linkage is different.

3 speed switch needs to be grounded. IF you are testing the switch hanging out down the dash and still not mounted, run a ground wire to the switch

DON'T ASK HOW I KNOW

2 speed doesn't need ground

wiring is the same.

linkage is diff, at least main one and motor crank.

several years had diff linkage setup, some with nylon bushings some with retainers. Make sure you find the right main link and crank to your pivots and pivot link or a complete setup

thanks for the reply can i ground the switch from the body of the switch or where it contacts the metal where it screws in cheers steve ps or into the spare connector on switch

just tie a wire to same switch chassis... swicth gets the ground when is mounted throught the body