I recently changed the original motor for a part's store rebuild (yeah, I know, but the price was barely more than to local junkyard offerings that were all out of cars older than my van)

I never really looked at the original and the new one side by side. (I ordered the new one, pulled the old one, dropped off the core wrapped in paper towels, and picked up the new one.)

When the old one was on it's way out, it only worked at the higher speed, wouldn't send the wipers to the down position when switched off, and mostly didn't work if it was raining (It's not that I'd only notice it wasn't working when I needed it. Every time I had the weather to find what was wrong, it'd work for me.)

Last week it was raining like mad and the motor cut out. I pulled over and moved the linkage by hand. The motor started going, wiped 2 cycles and quit altogether.

When I put the new one in it didn't work. I noticed it had a ground lug with no cooresponding harnass connector. I grounded the body of the motor with jumper cables and it worked.

I made a lead to connect the lug to a screw on the firewall that attaches a ground for something else. It works fine now.

The van originally had a bunch of options that I had eliminated. Those on the column included: tilt, cruise and intermintent wipers (I got a bare-bones junkyard column to simplify life and remove tilt steering slop).

Is it possible that the old motor was somehow grounded by the intermintent wiping wiring in the old column? Is it further possible that simply grounding the old motor would've worked as well? (and that when it worked, it was just accidentally grounding itself?)

(I did notice that the new one weighed a lot less than the old one. I chalked it up to a lack of water, filth, rust, etc).

The year of your van is important, as well as whether it has the 2spd or 3/variable spd wiper motor.. The 3/4" wide ground strap on the wiper motor to the stud is important and sometimes breaks; wiring changed in later models. I don't think they added intermittent wipers until 1978? maybe - the factory actually modified the wiper motor somewhat. I have added intermittent wipers to a '75 2sp, but it was difficult and expensive - I added a Hall effect sensor to tell me where to stop the sweep and build a fairly complex control box.

From memory, I don't seem to recall the factory delay being on the ground side; I thought it was on the low speed feed, but I could well be mistaken.

Mopars w/ hidden wipers reverse the motor direction to park, so a problem in the switch or wiring can cause many problems. Some early FSM were sometimes vague, but the '74 & '75's, I seem to remember, show the logic inside the switch. An appropriate *factory* schematic would tell you for sure.

I am trying to figure out how to repair the "Park" function on my 1970 Dart with Variable wipers. All the grounds are correct and good. Anybody got any help on this issue? Let me know.

Later,
Bruce B.

_________________
bruce@7071dartgt.net come and visit: www.7071dartgt.net not all slant 6 cars but most were.

Every time (but once) I've seen the park fail, the little switch & cam was broken inside the wiper motor housing. I've know of no source for replacement parts, but there must be one for people who rebuild the motors. If the switch doesn't open properly, the motor keeps going and breaks the plastic cam.

The one time it wasn't the internal switch, it was due to a bad ground of the dash wiper switch itself. The 2sp switches (usually) don't need ground, but it's essential for the 3sp/variable switches.