Wiper delay not working right, works on low and high

[Snoots]

The switch in the motor is like the contacts of a relay. You may want to look at them first, use a points file on them before you go spending money.

 

[echo7bravo]

Back to Crispy's initial post.....my wipers have the same symptoms where they work in low and high but not in delay. Nor do they park. If I turn to off position the wipers stop in place.

I tried jumping the #3 and #4 terminals to check the park and wipers did not move when ignition was on and wipers in off position.

I'm going to try tracing all the wiring to check for breakage first.

 

[chengny]

Back to Crispy's initial post.....my wipers have the same symptoms where they work in low and high but not in delay. Nor do they park. If I turn to off position the wipers stop in place.

I tried jumping the #3 and #4 terminals to check the park and wipers did not move when ignition was on and wipers in off position.

I'm going to try tracing all the wiring to check for breakage first.

Wait on that for a bit - tearing into the wiring harness and column sucks.

First, make sure that - with the key on - you have 12 VDC at terminal 4. By that I mean, on the plug side - not at the socket on the motor casing.

If you confirm power coming into the park switch on 4, find a way to supply that terminal with power - while still being able to attach a jumper from terminal 3 to ground (on the motor side). That might require:

Running a long jumper from the battery and a jumper to ground

Cutting the clip off a jumper (and stripping the insulation off that end), sticking the bare copper into the harness plug @ 4 and clipping the jumper to the male spade on the motor. Same as above schematically, just a shorter wire and you don't ruin a jumper.

Or maybe connecting the plug/socket as normal and cutting the ground lead. Strip it and attach a jumper to the bare copper and then to ground. You can always solder and heat shrink the splice after you test. It's your call.

See if that will make them run.

There is still a possibility that the module is defective. A bad module shouldn't prevent the wipers from parking. But those black boxes are a mystery and when they go bad, the wipers can do strange things.

 

[echo7bravo]

Wait on that for a bit - tearing into the wiring harness and column sucks.

I will do that. I want to start at one end and work my way to the other checking for multiple problems. With this truck having so many wiring issues, I wouldn't be surprised if it is a frayed wire that is keeping power from reaching the park switch.

 

[chengny]

I will do that. I want to start at one end and work my way to the other checking for multiple problems. With this truck having so many wiring issues, I wouldn't be surprised if it is a frayed wire that is keeping power from reaching the park switch.

You'll figure this out. But, there is one thing you've got to keep in mind when troubleshooting this circuit. And sometimes it's easy to forget because it's counter-intuitive; this is not a power supply issue, but rather a ground path issue.

What you are trying to determine is; where continuity to ground is being lost (and only in the parking circuit leg). There are three paths to ground; one each for HI, LO & PARK. You report that High and Low speeds will run all day long with no problem. It is only when you move the switch to OFF - and break continuity for the Hi & LO windings - that you have a problem. With no ground for the LO speed windings on the gray wire, the PARK switch (and it's ground leg) are supposed to bring the wipers home. So - even disregarding the delay issue - since the wipers won't ever park there must be a lack of continuity in the wire labeled as #5.

I have to be careful to avoid calling wires by their colors - I am extremely color deficient - and the wiring diagrams for this system are pathetic.

See if this helps. Red tracer is the hot side (power in) and gray is the two possible grounds paths for the LO speed windings. When you turn the switch off current continues to flow through the park switch contacts until the wipers are home and then the cam opens the circuit and shuts the system down:

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[echo7bravo]

Jerry, I can't thank you enough for your knowledge. And not to mention your ability to spell things out to where even I can understand them.

I haven't had to time to tinker the past few days. Momma had me on her to-do list. I'm going to try to run down the wiper circuit tomorrow or Wednesday. This truck has proven to be one heck of a project.

 

[chengny]

You'll be on your own for a while. But you might want to try this: Eliminate the pulse module as the problem by removing it from the circuit. Of course you won't have intermittent wipers, but if the wipers do go to the parked position with it out installed...you will know there is a problem with the module. The module is designed to be plugged into an existing non-intermittent circuit using the existing connectors. Just unplug the module on either side and then reconnect the two connectors. So instead of this:

You must be registered for see images attach

You'll have this:

You must be registered for see images attach

In that case I would try a new/different module.

 

[echo7bravo]

My head hurts from thinking about electricity. I'm following you on what you are saying. And will let you know my findings.

I see that 91-Gray is the ground for Terminal #2 for the LO speed ground. And that ground keeps grounding the low speed wipers till they do in fact park.

I see that 91-Gray is also a jumper from Terminal #2 to Terminal #3 where the ground signal passes through the park switch and out on 97-Black/Light Blue on Terminal #4 back to the switch where it grounds.

I see that the motor constantly has positive power and the switch rotates the ground signal from HI, to LO, to Off. So when the switch is turned to the Off position it should ground out the Black and Light blue wire from Terminal #4 causing the cam in the park switch to engage and park the blades.

I am going to put the wipers in the LO position on the switch and splice in a jumper from the black and light blue wire (circuit 97) from terminal #4 to a known ground. The wipers should park themselves if the park switch is good right?

If not, on to more troubleshooting.

 

[chengny]

I am going to put the wipers in the LO position on the switch and splice in a jumper from the black and light blue wire (circuit 97) from terminal #4 to a known ground. The wipers should park themselves if the park switch is good right?

If not, on to more troubleshooting.

Yes, but before doing that test, I would first try removing the pulse module from the circuit. Run the wipers normally and see if they will go to park with the module out of the equation. That way you won't have to cut into your wiring.

If they still won't park (with no module installed) then try jumping the BLK/LT BLU straight to ground - with the module still out.

 

[echo7bravo]

I'm definitely going to bypass the pulse module first thing. Just one less item in the equation.

 

[echo7bravo]

The results are in. Unplugged and bypassed pulse module for intermittent wiper mode and wipers now park as normal. Looks like I will be purchasing a new pulse module.

Wipers still seems unusually slow (like everything else on the truck). Will be double checking all the grounds over the next couple days.

Thanks again to Jerry.

 

[Big Chip]

So I took the burb out the other night in the snow to see what the Cooper ST Maxx's, my brakes, and the 4wd system can do. They all passed with flying colors and I've confident in the Mrs vehicle now.

I did find out that the wipers, when set on to delay just kind jerk an inch or so into motion. If I turn them up to Low from the delay position they work fine. If i turn the wipers to low from the off position they work fine as well. Same for high.

It seems like there is an issue with the delay. Is there something I can do to trouble shoot or fix this?

Were you able to get yours fixed?


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[Crispy]

Were you able to get yours fixed?


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No, I have the trouble shooting PDF printed out and hope to tackle it this weekend. I'll post my results. It rained last night and I was reminded I had a wiper issue lol.

@echo7bravo Mine seem a little slow and clunky as well, when they work correctly. Maybe try greasing the pivot points on the wiper transmission. I had a similar issue with my gmt400 and some grease smoothed out and quieted the operation.

 

[echo7bravo]

I'm a little A.D.D. when it comes to working on this truck. I have so many things that I am working on simultaneously that I bounce back and forth. The pulse module was definitely the culprit on the wipers not parking. I need to buy a new module and want to change out my turn signal stalk since I no longer have any kind of cruise control.

Once I get done working on the interior moldings, I plan to go back to the slow, clunky wiper symptoms. I will check lubrication and ground contacts and even running motor without blades attached to check torque of the motor.

 

[Crispy]

I tried the above trick in bypassing the pulse board and now low and high work great on the first switch of the stalk instead of randomly. The wipers also return to park everytime which they werent doing before.

Ordered a new AC Delco pulse board. Will report back in a couple days when I get it.