82 Wiper Motor

[9999]

82 K10

Wipers not working. Fuse panel writing is not well labeled (faded). Found a close match fuse diagram. 2 speed dash switch.

The wiper fuse (I think from the diagram) has 12v on both sides of the fuse with the key off.

3pin motor connector. 1 pin no power with key on or off, 2 and 3 pins each have ground when key on and switch on low and high respectively.

The 2 pin for the washer motor has 12v with key on for one of the pins.

This tells me, the washer motor but not the wiper motor is getting power. If it were a fuse the washer connector would not show 12v. With the grounds working properly from connector using the high and low switch I think the switch is good (I believe it just grounds the circuit and doesn’t ever see 12v.

My next step is to rig up wiring to power the motor directly and see if it works. After that it has to be somewhere after the fuse panel in the wiring before it gets to the wiper plug right?

 

[SirRobyn0]

There have been numerous discussions on wiper issues. If you haven't seen these threads you should take a look at them.

https://www.gmsquarebody.com/threads/85-91-wiper-motor-rebuild.36321/

Rebuilding wiper linkage - How to

Newer cars when there is problem with the wiper linkage the solution is to purchase linkage and replace it, but on these old trucks in most cases you can service / rebuild it. Though you can no longer get an entire assembly at your local auto parts store places like LMC do still have them, but...

www.gmsquarebody.com

I'm going also say this. Do not overlook the ground tab on the wiper motor. Even if it looks good try connecting a ground wire from the negative of the battery directly to the housing of the wiper motor. Grounding issues are very common, and folks tend to overlook that.

It is not common for wiper switches to go out but it does happen.

If your truck has delay the delay boxes do tend to have problems.

Good luck. Oh, and don't forget to check that ground!

 

[Doppleganger]

There is a plastic (old-fragile) part that holds the brushes and springs - I found this broken many times. When it breaks, you lose the tension on a brush spring, so either lose a speed or power in general. That link SirRobyn shows this (#8).

I have a 79-84 motor I'm going to rebuild with pics shortly, but the 85-91 motor wise is pretty much the same.

 

[9999]

2 things going on from looking at it more yesterday.

I added 12v to the power on the motor and grounded the low and high individually. It never came on.

The 12v wire leading to the connector had been spliced previously and doesn’t have 12v.

Plan for today is get the motor connector switched 12V from the wiper lead, and test. Also add an additional ground strap as mentioned about to rule that out.

If still isnot working I will pull the motor to diagnose and see options.

 

[SirRobyn0]

2 things going on from looking at it more yesterday.

I added 12v to the power on the motor and grounded the low and high individually. It never came on.

The 12v wire leading to the connector had been spliced previously and doesn’t have 12v.

Plan for today is get the motor connector switched 12V from the wiper lead, and test. Also add an additional ground strap as mentioned about to rule that out.

If still isnot working I will pull the motor to diagnose and see options.

If you decide that the fault is in the motor, rebuilding it yourself is a great option. If you don't want to do it yourself, be aware that there are a lot of low quality rebuilt units most made by A1Cardone / Cardone industries, though sometimes under store brand names. Please do not buy one of those. Autozone sells and O'rielys can order WIA wiper motors which are new, and are good. If your up to going though it yourself and rebuilding your unit that would probably be best.

 

[9999]

103 degrees didn’t motivate us today.

Looks like they have a new WAI for $75 local I may grab to swap Saturday morning if I can’t get it this week.

We need to swap the alternator first also. Trying to get it inspected this weekend, so may try the WAI and save the original to rebuild.

Thinking of swapping in the 85 type without the washer pump tied in. The existing washer tank and lines are shot, so now may be the time to switch.

 

[SirRobyn0]

103 degrees didn’t motivate us today.

Looks like they have a new WAI for $75 local I may grab to swap Saturday morning if I can’t get it this week.

We need to swap the alternator first also. Trying to get it inspected this weekend, so may try the WAI and save the original to rebuild.

Thinking of swapping in the 85 type without the washer pump tied in. The existing washer tank and lines are shot, so now may be the time to switch.

You know you can run the older type, leave the wires off for the pump. I have no idea if the mounting is the same or not @Doppleganger - Chris is more likely to know.

 

[9999]

Put in a new WAI for an 85, and stole key on power from the wiper connection and they work on low and high now.

I didn’t think about the power to the park connected and think I need to add it there as well.

The older style motor was $40 more, so getting the separate wiper pump and reservoir won’t be that much more expensive in the long run and more reliable I believe.

Was able to get it inspected today.

 

[9999]

The park function was working. I had the linkage 180’d out. Fixed that and all good.