I'm in the process of trying to get the 72 charger ready for the street. (finally )

I bought a used 3 speed wiper motor off a memeber here little over a year ago as best I can recall. Finally getting it hooked up. To my surprise when I plugged it in it actually worked. I really thought the wiring might have been cut or removed as this was a race only car for a while (previous owners).

Now, when the wiper linkage was disconnected everything looked and sound normal with the way the motor was running.

Now, with the linkage hooked up and wiper blades on the slowest speed seems to work OK, the second sped the blades move a couple inches then stop (unless I move them by hand then they do it again) and on the highest speed nothing moves at all.

Also, sometimes when I shut them off they don't park like they should.

I'm thinking the motor may need to go to Jule's but wanted to hear your thoughts.

If it has fire uninterrupted in all of the wires to the motor & it is grounded well I'd think it would be the motor especially the not parking part since when you shut off the switch the motor is still energized via another wire & rotates a bit more then another circuit inside the motor breaks contact to stop it after it's parked. I would wait for Jules tho

Check your grounds, as in electrical,
wipers add drag which requires more current as do higher speeds,

From what I remember the 3 speed wiper motor is a shunt type motor as thats how they change speeds by grounding in a shunt field winding to slow the speed. On that type the switch does the grounding but I cant be positive without seeing the wire diagrahm of that wiper motor. The wiper motor on some got fed 12 volts at all times and when you turned them on the switch would ground the series or/and the shunt windings and when you turn the switch off the park switch kept it grounded until the park switch contacts open as the wipers are on the bottom of the windshield. I honestly have not had to troubleshoot that system for many years as I have not had any problems with mine or my friends cars. But its a good chance its the switch and of course either the switch or motor can really cause the problem. Also most Mopar wiper motors have circuit breakers in the motors and/or the switch. Ron

I will check the grounding of the motor.

Also, I would think if it's a tripped breaker it wouldn't work at all true?

Was it originally equipped with 3 speed wipers ??

As the only thing I have as a reference is the dash was in the car when I got it and it is a 3 spd switch in the dash I think so. I don't have a build sheet or fender tag to confirm though.

Does it have 3 speed linkage?

It can be a number of things from the info we have so far.
The motor is used and can have internal issues, the wiring may be in poor condition
and lastly the dash switch may be on its' last legs.
I would start by testing the motor all on its' own using the shop manual.
Once that checks out , then test the dash switch. If both are good then
check the linkage for any worn or broken parts . Lastly check all wires for
poor contacts and /or breakage.Most important make sure you have good clean contacts
for the grounds.
Jules

Good thing I bought the maunals ( I'm assuming it should be them same as the 71 which is the maunal I have )

How can I tell if it's a three speed linkage?

As with the switch, it was in the car when I got it but as we all know that doesn't automatically make it right.

May take me a bit to get the time to get out there and go through all the testing though.

The book shows pictures of both 2 and 3 speed linkage

Well, here's a little bit of an update.....

I didn't get a chance to do any real trouble shooting as I got home from work late tonight but I did take the opportunity to check a few of the simple things.

Adding a ground (jumper) wire seemed to help as did having the engine running to be sure there was constant good power.

Then I had a brainstorm and thought maybe if I had the windshield wet like it would be if it was raining.

So I grabbed my spray bottle of window cleaner and low and behold if I kept the windshield wet everything worked on all three speeds.