Wipers won't stay down

[chengny]

I should add that the wipers stroke perfectly, they just park in the middle when I turn off the switch... so it can't be a linkage issue.

Read this, I wrote it awhile ago when I was more focused - it might be of help to you:

When you go to reassemble the crank on the motor shaft be SURE that they are indexed to each other correctly. By that I mean, it is important that both the motor and wiper arms are in the fully parked position.

The crank arm can go on the shaft in 2 different positions. If the arm is 180 degrees off from the normal angle, it will suck.

The first time you operate the wipers, the blades/wiper arms they will work beautifully - except for the fact that when the power is turned off, they will park at the top of the windshield. You will have to do the job again.

The wiper arms are easy - just push them down to a point where the blades are almost touching the windshield gasket.

To preset the motor to park position, just plug in the wiring harness connections, turn the switch on and run it for a couple of revolutions. Turn the wiper motor off at the switch and then mate the motor shaft to the crank arm.

It might sound wicked involved, but everything will become obvious as you do the replacement.

Link to the OP:

http://www.gmsquarebody.com/threads/wiper-issues.9566/

 

[RustyPile]

At least yours would stop when they were down if you turned the switch in the right place. If I turn my switch off when they are in the down position, as soon as I turn the truck back on they go right back to the middle

I read this post correctly but interpreted it wrong.. I thought the switch you're referring to is the wiper switch but you're referring actually to the ignition switch.. The problem is not in the delay circuitry as I originally stated.. Here's your problem.. You have the wiper motor arm "clocked" wrong on the motor shaft. Turn the wipers off at the wiper switch. Allow them to park wherever and then turn off the ignition switch. Remove the nut and arm from the motor shaft, them move the wipers to the park position.. Then re-attach the arm to the shaft..

Thanks to chengny for slapping me back to awareness..

 

[Gray87GMC]

Thanks for all the help guys. I'll tinker tomorrow and see if I can get things all fixed. Hopefully I report back with a happy story lol

 

[Gray87GMC]

Alright guys... I flipped the linkage where it connects to the motor 180 degrees and tried it out. The wipers tried to go down further than than the arms would allow. So it seems someone has messed with the arms also. I took them off and put them back on where the motor showed them in the parked position. Now they work and park, but they only go up about 75% of the way on the stroke. I greased the linkage and made sure nothing was binding up but no go. So at least they're functional now... but still not 100% right. So frustrated with this. I've already spent 150 dollars on parts. Any more ideas?

 

[RustyPile]

Alright guys... I flipped the linkage where it connects to the motor 180 degrees and tried it out. The wipers tried to go down further than than the arms would allow. So it seems someone has messed with the arms also. I took them off and put them back on where the motor showed them in the parked position. Now they work and park, but they only go up about 75% of the way on the stroke. I greased the linkage and made sure nothing was binding up but no go. So at least they're functional now... but still not 100% right. So frustrated with this. I've already spent 150 dollars on parts. Any more ideas?

With a mis-match of parts, trouble shooting will be difficult.. this is just a WAG on my part, but I suspect the arm on the motor is wrong.. It could be the wrong length ( too short) and with the resultant shorter stroke, it can't push the wipers all the way across the windshield..

 

[Gray87GMC]

With a mis-match of parts, trouble shooting will be difficult.. this is just a WAG on my part, but I suspect the arm on the motor is wrong.. It could be the wrong length ( too short) and with the resultant shorter stroke, it can't push the wipers all the way across the windshield..

I suspected something similar. Thanks for the extra input. Guess I'm going on the hunt for new linkage! Who knew something as simple as wipers could be so much fun lol

 

[RustyPile]

I suspected something similar. Thanks for the extra input. Guess I'm going on the hunt for new linkage! Who knew something as simple as wipers could be so much fun lol

Part of the joy of owning an old vehicle.. You'll always run across situations like this when dealing with old cars/trucks.. Comes from previous owners not knowing what they're doing, can't locate the proper parts to repair, and just plain old redneck engineering.. You should have seen what I went through just to make the fuel gauge, temp gauge, and oil pressure gauge work on my recently acquired GMC Classic...

Back to your problem at hand.. Some of the parts reproducers might have the linkage available but It'll probably cost an arm and a leg.. Nothing wrong with used parts of this type.. No sense in replacing all the linkage.. Probably all you need is the arm..

There's a pick & pull in my area, and it's full of old square bodies. I might be able to help you locate what you need.. Do this.. Park the wipers in the normal way by turning off the wiper switch -- makes no difference if the wipers are way up on the windshield.. Remove the wiper arm at the motor.. Push the wipers down to the park position.. Measure the distance between the center of the motor shaft where the arm attaches and the point where the other end of the arm attaches to the linkage.. That's pretty much the length arm you need.. If you can't locate an arm, let me know and I'll see what I can find..

 

[rpcraft]

Not sure if you answered earlier or not but if you responded I am sorry. Does the blinker stalk on your truck have the wiper delay on it? If so then you mentioned you did not see a module and that the wires were just plugged into each other originally on your post (I think). There should be a large module on the bottom of the steering column that has silver heat sinks on it and if you look closely it should have a number on it (15598495 7313 is what mine was). That is the delay module and I'm just wondering out loud but if it is missing (or bad) would it cause an issue with your wipers not parking where they are supposed to? The linkage was a good thought but he had already mentioned that the motion was correct on the windshield so either its a park switch as you guys suspect, or some kind of interruption, which is what the intermittent wiper module controls, so if he has it missing then it might be the issue....

Fwiw my Jimmy is a 1985, has the intermittent wiper, and has a motor that does not include the pump (from what I recall).