89 Chevy wiper nightmare

[buffip]

Guys,
89 Chevy 4WD auto 305 Intermittent wipers, "Control module" style rear anti-skid ONLY
Wipers went totally out (froze) during rain. Simultaneously, received a "BRAKE" warning light. Brake warning light went out, wipers started working. Cycle repeated 1 more time, then no wipers, and no brake light. Shot with meter at fuse, and showed 12 volt. Shot at wire harness at wiper motor, and showed good voltage. Replaced wiper motor, and everything ran great for 2 weeks. Last night, same scenario reoccurred. Brake light, wiper inop. This time however, BRAKE light on very dim, and wiper motor humming. Found by manually pulling on wiper, could make motor turn 1/2 a cycle electrically, but did not have enough torque to run wipers steady. Today in garage, wipers are back to normal. I suspect a bad control module or a bad ground. Any help out experience out there?
Thanks
LJ
Off to buy Rain X

[jkinney]

Ditto on the rain-x thing, I have a 93 Z-71 and the wipers did the same thing. I went to a junkyard to get a temporary fix, and they were sold out. Seems to be a common problem on these. I went to purchase a new one and the guy at the parts store "heard" that they had a bad ground in them, and were notorious for going out. I put a small ground strap on one of the bolts and attached to the firewall since it is mounted (and isolated) on rubber grommets. Havent had a problem since (over a year). Dont know if the brake light is involved but would be curious if they were adjoining circuits? When the brake light comes on again, pull off the connector on your proportioning valve and see if it dissappears. It might be supplying a ground to "whatever" (wiper motor -maybe) and could explain why it came on dim the last time. Let us know what you find out. Good luck.

[TEXAS-HOTROD]

I have replaced so many wiper modules, it's not even funny. I have also done the ground strap-to-the-bolt trick too.

[94 Z71 Blazer]

I had that problem....UNTIL...I started resoldering the boards. I guess I solder heavier than GM cause mine and my brothers are still working with NO PROBLEMS!! About 5 cents of solder and your good to go! Check out this link for a play by play....



http://james.jaguar.net/subtopics/WiperFix.htm


So far, works every time...about one year now....and by the way, I don't have any additional ground strap. First I've heard of that one. The official report is that the solders "crack" and cause intermitent contact. Thus, works one day, not the next.

[jkinney]

Great link 94 Z71 BLAZER.