My wiper motor seems to be going south. I swear, this car was rock solid for 5 years, now it is one thing after another. What I need to know is the interchangability of wiper motors. Will motors from other models fit my 74 Duster? It is much easier to find 5th Avenues than Dusters in salvage yards.

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ifyoubegintothinkyou'relosingcontrol...it'salreadygone

2-speed and 3-speed motors were available, and they are different. (If you're changing from 2-speed to 3-speed, you also need the correct switch). Interchangeability data as well as parts sourcing comes from car-part.com.

Make sure the motor has a good ground.

Also the wiper switch in the dash needs to be well grounded. If the hold down nut gets loose, that can cause funny problems.
DD

If changing from 2-speed to 3-speed motor (or vise versa) you also need the correct linkage under the dash. There is a slight difference (not sure what it is) and you can't mix 2-speed and 3-speed parts.
I know the (at least some) of the 3-speed motors have a "park" position that activates after you turn the switch off, the motor reverses and some mechanism make the wiper park lower down on the windshield.

I once put a 3-speed motor and switch in my '75 Valiant that had a 2-speed motor and did not know I needed different linkage. It did not work. Had to put 2-speed motor back in.

In the TMC giveaway cars (www.tidewatermoparclub.com), I've interchanged lots of wiper motors. If I may, let me give you some swapping advice. Note that 70s vintage variable speed and 3 speed motors are essentially the same - the difference is inthe switch.

1) I've done several 2 to 3 speed swaps; they involved many electrical changes & I don't recommend it unless you want to do lots of extra work and take the wiring harness out of the car so you can modify it.
However, I was always able to use the same long arm that went to the pivots and the short arm that came with the motor. Note that the park position on 3 speed motors is adjustable for different models.
While 2 speed switches usually need not be grounded, 3 speed switches generally require a good ground for the motor to properly park. Without a ground for a 3 speed switch, one of the motor's windings will always be on and eventually stuff will melt.


2) even among 2 spds that look similar, beware that those w/ and w/o ballasts do not interchange electrically


3) even if they electrically interchange, trucks and cars at least sometimes used differently keyed arms so they'd park in different places, so use that short arm that came with the vehicle


4) since the replacement motor may not park the same, do NOT put the wiper arms on until you've tested everything and let the motor properly park

In my '65 Dart, I have a single speed wiper setup. Can I use a variable speed switch with this setup? Do you know where a new single speed switch can be found?

The TMC did a '65 Barracuda a few years back (see www.tidewatermoparclub.com for photos); I reworked the wipers and switch.

There is no compatiblity between the '70s 3/variable speed setup and the 1sp.

However, if your setup does not reverse direction to park (like ours, I think I remember), you could add a time delay fairly easily. If it does reverse directions to park, no delay I've seen on the market will work right.

While it is possible to build such a delay (I've done it), it is a LOT of work - I used a Hall-effect sensor to find the stop point for '75 Coronet.

While a power resistor could be used to slow the motor down, you'd also reduce the torque available to overcome friction.

I have a problem with my wiper motor too. Now, when you turn it off, instead of placing the blades back to the "initial" position, it just stops wherever it is, in the middle of the windshield, etc. It is really annoying to have to turn it on again and stop it at the right place before it goes up again...

Any comments...

Thanks,

Ed

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My other car is... another DUSTER!!! .·.

Yeah, try replacing the switch. Mine does that as well; when it does I simply push on the knob and the wiper continues along and parks.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Thanks Step... I couldn't imagine that the parking of the arms was controlled by the switch... I think I'd clean and spray it with some silicon to see if it gets fixed before I replace it.

Ed

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My other car is... another DUSTER!!! .·.