Windshield Wiper Motor Questions

[mrsnicks]

I picked up a basket case 71 Plymouth Satellite. It has a Rallye cluster and a non-2speed wiper motor.

It included two different switches, a 3 speed switch (click, click, click) and a variable speed switch (click/sweep, click).

The wiper motor has a part number of 3431096 that is inoperable.

My QUESTION is, are the wiper motors different between 3speed and variable speed?

Thanks in advance!

 

[gkent]

They are listed as two different animals so I'd have to say they're different. A "variable" would need to have a potentiometer to control the voltage - much like your lights dimmer, whereas the two speed uses the big white resistor to control the slower speed and the three speed units use both a resistor and different windings.

 

[mrsnicks]

TA "variable" would need to have a potentiometer to control the voltage - much like your lights dimmer

But wouldn't the potentiometer be in the switch, much like the light switch?

 

[ns1aar]

But wouldn't the potentiometer be in the switch, much like the light switch?

71 E and B body both use PN 3431077 wiper motor. The switch is what controls whether its a 3sp or variable. 71 should use a variable switch

 

[gkent]

Yes, the pot will be in the switch. But I "think" you also need a variable speed wiper motor - not a 3-speed

 

[Nacho-RT74]

Variable/3 speeds motors "are the same" ( althought they changed a bit externally and internally along the years.. I think on 72 ). They will work with any of the switches, the sweep variable kind used on 71 and the fixed 3 speeds switch ( off, low, mid, high ) used after 72. BTDT

2 speeds motors will work just correctly with the matching 2 speeds switch, no matter if 71 or 72/74

All 71 switches are diff from all 72/74 BUT will work on either of the years breakdown.

On my 74 I have a 3 speeds motor listed for 72 by the PN and I matched it with a 71 sweep kind variable speed switch. Also works with the fixed 3 speed switch. Although for 74 the correct setup is the 3 speeds I found more interesting use the variable which by casuality ( not searching it ) came with the Rallye cluster I got. Of course changed the wiper plugs on harness, because plugs for the switches between 71 and 72/74 are diff ( no matter the speeds, is a diff configuration ). Wiring is the same thought, just a diff prongs disposition

 

[Nacho-RT74]

Need to note, the variable speed switch is click-sweep... no click-sweep-click

 

[ns1aar]

Been restoring wiper motors for along time
The prestolite wiper motors as used by mopar are the same electrically and are all capable of being a 3sp or variable it all depends on the switch
The parts book is misleading when it uses variable. Its the applacation of the part not the part

 

[Nacho-RT74]

But if the OP got a 3 speeds switch ( 72/74 ), the prongs disposition is diff from the variable speed (71) so "needs" to get the plug for the switch used... 71 or 72/74.

As far I recall, E bodies and also A bodies changed the same on the prongs disposition like B bodies ( no matter if Rallye or standard cluster ) on those years, so could be grabbed from any Mopar harness and also from 2 or 3 speeds car.

Wires could be connected individually without the plug insulation thought

 

[Nacho-RT74]

71s uses two plugs like these

While 72/74 uses this one piece plug

 

[Nacho-RT74]

Switches side by side

The shaft lenght just makes diff between standard and rallye clusters. Long shaft is for standards cluster on B body. Every switch has its standard cluster version. On the pic for example we can see the 72/74 3 speeds for Rallye and for Standard clusters

And pretty sure same diff applies for diff bodies, with diff shaft lenghts and nut attaching for each cluster body kind but everyone being pretty much the same switch, but if the attaching nut, hole provision on dash/cluster, shaft lenghts, room behing the dash/cluster allows that, you could use an 73 A body switch into a B body cluster. Electrically they must be the same.

sure another diff would be if manual or electric pump washer. All these switches on pic are a built in washer pump push in function. A bodies could be foot pump or electric so this makes a diff into the switch, but motor itself will work the same with either switch

 

[gkent]

The parts book is misleading when it uses variable. Its the applacation of the part not the part

That's what was throwing me off.

 

[mrsnicks]

Thanks for all the replies, very helpful. Final question. How do you bench test a wiper motor? Thanks.

 

[gkent]

How do you bench test a wiper motor?

You start by opening the FSM to the "Wipers" section !!

 

[383man]

Yep the wiper motors are the same. Most manufactors use what they call a Governor unit that works with the switch potentiometer to work the intermitting wipers if thats what you are talking about ? Now two and three speed wiper motors are different because they work different most of the time. The 3 speed motors use the current flow in the shunt & series windings to control the speeds by resistance in the switch at different speeds. The more current the switch sends into the shunt winding away from the series winding the slower the wiper speed. So the low speed will have less ohms in the switch for that speed position to the shunt winding so more current to the shunt winding slows the wiper speed and then the speed gets faster as the switch puts more ohms into the shunt winding so more current goes to the series winding and the motor runs faster. Now most 2 speed wiper motors use different brushes and the resister located on the motor to control the speeds. Ron