1985 K10 Wiper Issues

[TrivTen]

Hey guys,

I know that I am kinda beating a dead horse here with how much this has been discussed, but I am lost here..

Background
I’ve got an ‘85 K10 Scottsdale (that has prior wiring modifications and some dead ended rats nests) and ever since I got it, the wipers do not work. Every once in a blue moon, when I turn the wipers on, they will quickly bump down an inch, like they’re returning to home position. I have done some wiring to fix the headlights, as some had bad grounds or needing connectors replaced.

Wiper Delay Control Module
I do have the infamous wiper delay control module. I’ve tried to bypass it, by disconnecting the two ends and connecting them together, but they have both male ends. I took apart the delay module and tried to check the board to see if I could find anything. I tried to follow a schematic I found on the forums, but didn’t know what I was doing.

Wiper Control Switch
I do not know how to test the control arm. I have the style that is a single wiper control twist top, and up/down for the turn signals. My indicators do work as intended, just with some loose play of falling out of indicator “on” position. I attached photo to show style. As mentioned above, once in a blue moon if I flick the control on, they’ll quickly bump down an inch. If I try to turn on the killer power jet washer fluids, I am left in disappointment of nothing. Turn signals work as you’d hope.

Wiper Motor
To be honest, I am not too sure what to look for here. I did ensure there is a good ground, and the terminal block it’s plugged into has power. I don’t hear anything hum or kick on when trying to run the wipers. So I feel it’s before the motor, since sometimes I get that quick bump down.

I am no professional, or claim to be, when it comes to this stuff. Just a younger guy that has always had a passion in this, and finally got his toy. I would appreciate some help, as I am a first time poster… but long time lurker. I apologize again, as I’m posting another wiper post.. Thank ya’ll in advance!

 

[SquareRoot]

Welcome! My 85 K20 wipers are a similar S**t show. I replaced everything except the motor with AC Delco parts and it still only works on Low speed. I took the new delay module out and ran it straight thru and it's still a POS. Fortunately, I live in Yuma AZ where it rains maybe twice a year so it's no big deal. I hate everything about the wiper system on these trucks. Probably didn't help you any but I feel better every time I vent over it.
@Ricko66 will be along soon. He can probably point you in the right direction.

 

[TrivTen]

Welcome! My 85 K20 wipers are a similar S**t show. I replaced everything except the motor with AC Delco parts and it still only works on Low speed. I took the new delay module out and ran it straight thru and it's still a POS. Fortunately, I live in Yuma AZ where it rains maybe twice a year so it's no big deal. I hate everything about the wiper system on these trucks. Probably didn't help you any but I feel better every time I vent over it.
@Ricko66 will be along soon. He can probably point you in the right direction.

Hey, thanks! I am feeling the same way as I work on this trucks.. lol I bought some Aquapel the other day for it and so far it’s covered me once on the way home from the farm.

If you don’t mind me asking, how did you run the wires straight through? Was it as simple as everyone says, and plug the two ends together? Or am going have to cut and splice?

 

[82sbshortbed]

The ones on my 82 are huge pos! Plus I only have one on the driver's side and I turn it on with a wall light switch that the po wired up. Lol

 

[SquareRoot]

I just unplugged the module and the two ends of the wire harness plug together.

 

[gmbellew]

you should be able to bypass the delay module. the harness will plug into itself.

aside from that, I'd hit up the reference library for the wiring diagram or maybe the service manual and check out the diagnostics for inop wipers. my guess is you will be busy with the multi meter figuring it out, but if the wiring isn't too hacked up, you should be able to figure out where the issue(s) are.

 

[GTX63]

The ones on my 82 are huge pos! Plus I only have one on the driver's side and I turn it on with a wall light switch that the po wired up. Lol

Interesting. I wonder if a sliding dimmer switch would give it the delay feature.

 

[TrivTen]

you should be able to bypass the delay module. the harness will plug into itself.

aside from that, I'd hit up the reference library for the wiring diagram or maybe the service manual and check out the diagnostics for inop wipers. my guess is you will be busy with the multi meter figuring it out, but if the wiring isn't too hacked up, you should be able to figure out where the issue(s) are.

Thanks man for the suggestions! I have found the service manual for my gen of K10, and was finding diagnostic advice for everything but my certain issue. I tried to follow them and what I was finding was okay. I do know the fuses are testing okay.

The past owners used it as an old swamp logging truck. 36” swampers, with a Superlift 6in lift. I tore into the dash and found a rats nest of old CB wire, radio wire, AUX cables. And with top tier wiring! Continuous led wires, with multiple bare spots, so the AUX wires can fish hook around the bare spots! lol I rewired the headlights and signals because their harness had so many nip marks for other wires.

For the delay bypass, are the cables not supposed to line up? On the female I have _- -_ | _- -_. For the male I have all - - - - | - - - -. I attached pictures for better understanding. I forced them puppies together and I still didn’t have anything. Getting them back apart was a good time. lol I appreciate the help, ya’ll!

 

[gmbellew]

see if this helps

 

[Dleslie212]

Welcome! My 85 K20 wipers are a similar S**t show. I replaced everything except the motor with AC Delco parts and it still only works on Low speed. I took the new delay module out and ran it straight thru and it's still a POS. Fortunately, I live in Yuma AZ where it rains maybe twice a year so it's no big deal. I hate everything about the wiper system on these trucks. Probably didn't help you any but I feel better every time I vent over it.
@Ricko66 will be along soon. He can probably point you in the right direction.

I think I've told you before, but I grew up in Yuma. Live in Phoenix now, missing that Chili Pepper

 

[Jgonick]

The best I can tell from your picture the wires appear to line up. Female _---|--_ & Male ----|---
The outside wires on the male (usually brn) deal with the delay and should have a blank spot on the female.

A white wire (wht-93) will run directly to the wiper motor & wiper washer pump- It comes from the fuse panel (wiper fuse) and supplies the current. The wiper switch on the column grounds the circuit. Pink wire is washer. Purple wire is fast wiper. Gray wire is slow wiper. Black light Blue wire is for parking the wiper. Black wire is ground. To test to see if your switch is bad you could briefly ground the individual wires one at a time (female connector) to see if they work. Same principle applies at the wiper motor- (example- briefly ground the terminal that the purple wire connects to at the motor)

 

[Jgonick]

very basic schematic of wiper

 

[86Blueberry454]

Also check your physical connections under the dash for the speed control switch and on the wiper motor itself. My 86 (no delay) had the wiring harness changed before I got it and only worked on low speed, also the blades would not return to park when shut off. Come to find out the harness colors had changed and the previous owner just plugged things in. After I re-pinned the connectors to the proper orientation, everything worked as it should. thankfully!