Windshield Wiper Motor Upgrade

[Jwasnewski]

I have a 89 GMC Suburban with the old style wiper motor, With delay and tilt which has a credit card sized control module mounted at the bottom of the steering column. All wiper system parts are new but the wiper delay function will not work.

I read in an old thread somewhere that installing a later model 91 wiper motor with the C type control module on the motor is a bolt in fix. Supposedly, the plugs are the same on the motor. .

However, nowhere in that thread did it say how to connect the two harnesses together after the credit card style module has been removed from the base of the steering column. Or is the old module left in place and somehow impulses get through it to the new C type board.

Thanks.
Leroy

 

[animal]

@chengny @bucket @RetroC10Sport
One of these guy's might know. I thought that I had read that you could "bypass" the control unit by plugging the 2 ends into each other but I have never checked to see if they actually match up.

 

[Doppleganger]

This looks purtee.

https://newportwipers.com/product/1973-87-chevy-gmc-truck-wiper-motor/#switches

 

[bucket]

I have a 89 GMC Suburban with the old style wiper motor, With delay and tilt which has a credit card sized control module mounted at the bottom of the steering column. All wiper system parts are new but the wiper delay function will not work.

I read in an old thread somewhere that installing a later model 91 wiper motor with the C type control module on the motor is a bolt in fix. Supposedly, the plugs are the same on the motor. .

However, nowhere in that thread did it say how to connect the two harnesses together after the credit card style module has been removed from the base of the steering column. Or is the old module left in place and somehow impulses get through it to the new C type board.

Thanks.
Leroy

I'm not aware of the '91 squarebody getting a different wiper motor.

If all the components are in good condition, the factory wiper setup works very well.

 

[Jwasnewski]

I'm not aware of the '91 squarebody getting a different wiper motor.

If all the components are in good condition, the factory wiper setup works very well.

I may be wrong on the year at 91 but my set up does not have the pulse board on/in the motor face. The pulse board is impossible to find as well. I just read somewhere that a later model motor with the pulse board (C type) set up is a plug and play. Every part in my wiper system is new and the delay Still does not work. Frustrating and expensive.

 

[Jwasnewski]

@chengny @bucket @RetroC10Sport
One of these guy's might know. I thought that I had read that you could "bypass" the control unit by plugging the 2 ends into each other but I have never checked to see if they actually match up.

@chengny @bucket @RetroC10Sport
One of these guy's might know. I thought that I had read that you could "bypass" the control unit by plugging the 2 ends into each other but I have never checked to see if they actually match up.

I am going to look into whether they will connect together this weekend. I’ll look at the motor electrical connections too and see if they match up to a later year. No one has been able to determine why this oddball system doesn’t work including myself.
Thanks.

 

[SquareRoot]

I replaced every single component in my steering column, new multifunction switch and delay module. All AC Delco parts and that sum bitch only works on high/low, no delay.

I hate everything about the factory system. The wiper blades suck, washers suck, it all sucks even if it worked like it's supposed to. 85 K20.

I'm looking for later model system that can be adapted .

 

[bucket]

The later style wiper motor used in the GMT400 trucks with built in pulse board is 100% not a direct swap in place of the older style wiper motors.

Not trying to sound harsh, but if the system doesn't work, you just have a problem that needs figured out. It's not an oddball system, it was used in trucks and vans for over a decade. That's millions of vehicles. It's a fine system when the components are good and it works every bit as good as newer vehicles.

 

[SquareRoot]

I don't know. I can't find decent wiper blades for the application. They usually last less than a few months along with the washer hose that dry rots every summer. Slow speed barely moves the arms and high speed is erattic at best. Delay doesn't work even with new components.

 

[WFO]

I don't know. I can't find decent wiper blades for the application. They usually last less than a few months along with the washer hose that dry rots every summer. Slow speed barely moves the arms and high speed is erattic at best. Delay doesn't work even with new components.

I'm pretty sure the rubber problems started with the addition of ethanol to the wiper fluid in recent years.

 

[bucket]

Of all of them that I have driven daily, the wipers have performed nicely. The slow speed has been good enough to almost never need the high speed. I've had a couple delay modules go bad, but tossing in a good used one fixed the problem. The wet arm style wipers have worked well too, my only gripe about those is where the nipple is placed in the cowl for the driver's wiper. I had a habit of yanking that hose off of there when clearing off a heavy layer of snow.

Oh, and my old '86 had a minor issue with the delay that I believe the problem was the switch itself. There was very little modulation between max delay and minimum delay.

 

[AuroraGirl]

I replaced every single component in my steering column, new multifunction switch and delay module. All AC Delco parts and that sum bitch only works on high/low, no delay.

I hate everything about the factory system. The wiper blades suck, washers suck, it all sucks even if it worked like it's supposed to. 85 K20.

I'm looking for later model system that can be adapted .

you can have rainsense off my 98 park ave

 

[Jwasnewski]

The later style wiper motor used in the GMT400 trucks with built in pulse board is 100% not a direct swap in place of the older style wiper motors.

Not trying to sound harsh, but if the system doesn't work, you just have a problem that needs figured out. It's not an oddball system, it was used in trucks and vans for over a decade. That's millions of vehicles. It's a fine system when the components are good and it works every bit as good as newer vehicles.

I am making baby steps but it’s headway. The later style motor will not plug to my application as you state. However, it appears there are models that will but that’s another thread for another day.

My pulse board is PN 15597496 I believe. From what I can find, which isn’t much, this pulse board was used only in the following models. 84-87 Chevy/GM Trucks C, K, R, or V. 88-91 Chevy/GM trucks R or V. 84-91 Suburban.

This pulse board is at the bottom of the steering column in the line with the switch harness and the wiper motor. Female plug on one end, male on the other I think. Will verify this weekend. It has a heat sink. I believe I will find when I try this weekend that when I remove the Pulse board and plug the two harnesses together I will get get wipers less pulse. Not certain on that until I do it.

I need a wire color pin out schematic for the wiper switch Harness from the switch to the plug in at the pulse board and a wire color pin out schematic from the opposite side of the Pulse board to the Wiper motor if anyone has such a thing. Otherwise, I’ll have to see if a dealer has archives. Or start Ohm testing a bunch of wires.

The way this is installed leads me to a question. Did GM have two harnesses, one for no delay and one for delay or was there simply one switch harness so when the delay option was ordered it was assembled simply by installing this pulse board in line at the intersection of the two harnesses, then simply changing the stalk? Doesn’t make sense to have two harnesses but—— . I am trying to figure that out because I had someone install all new parts including this switch harness. If there are two different ones perhaps it’s the wrong harness. Hence, I need a schematic.
I don’t want to start yanking the column apart for no reason.

Thanks for any help.
Leroy

 

[bucket]

I am making baby steps but it’s headway. The later style motor will not plug to my application as you state. However, it appears there are models that will but that’s another thread for another day.

My pulse board is PN 15597496 I believe. From what I can find, which isn’t much, this pulse board was used only in the following models. 84-87 Chevy/GM Trucks C, K, R, or V. 88-91 Chevy/GM trucks R or V. 84-91 Suburban.

This pulse board is at the bottom of the steering column in the line with the switch harness and the wiper motor. Female plug on one end, male on the other I think. Will verify this weekend. It has a heat sink. I believe I will find when I try this weekend that when I remove the Pulse board and plug the two harnesses together I will get get wipers less pulse. Not certain on that until I do it.

I need a wire color pin out schematic for the wiper switch Harness from the switch to the plug in at the pulse board and a wire color pin out schematic from the opposite side of the Pulse board to the Wiper motor if anyone has such a thing. Otherwise, I’ll have to see if a dealer has archives. Or start Ohm testing a bunch of wires.

The way this is installed leads me to a question. Did GM have two harnesses, one for no delay and one for delay or was there simply one switch harness so when the delay option was ordered it was assembled simply by installing this pulse board in line at the intersection of the two harnesses, then simply changing the stalk? Doesn’t make sense to have two harnesses but—— . I am trying to figure that out because I had someone install all new parts including this switch harness. If there are two different ones perhaps it’s the wrong harness. Hence, I need a schematic.
I don’t want to start yanking the column apart for no reason.

Thanks for any help.
Leroy

I'll try to find it, there's a couple threads about the pinouts and I have posted a thread with a schematic of the delay module itself. But the wire harness is the same for delay vs no delay.

I'm still not certain what the "C" type wiper motors are that you are referring to. Here's the two designs used in the GMT400 trucks that came after the squarebody trucks:

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[Jwasnewski]

I'll try to find it, there's a couple threads about the pinouts and I have posted a thread with a schematic of the delay module itself. But the wire harness is the same for delay vs no delay.

I'm still not certain what the "C" type wiper motors are that you are referring to. Here's the two designs used in the GMT400 trucks that came after the squarebody trucks:

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You must be registered for see images attach

Thank you.
The C type just looks like a big fat C. I’ll try to post a photo of it and my application.

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