Windshield wiper mechanism help needed.

[Bob S.]

2006 BRM 180K miles; Windshield wiper assembly help needed.

Problem/Complaint: The windshield wipers are not making normal full sweep. With the wiper arms & blades off, the mechanism makes full movement. With either arm/blade on, the mechanism makes full movement. When the glass is sprayed with fluid, the movement is better. But, when both arms & blades are on, or, both arm & no blades are on (paper towels there to protect glass) the assembly will sometimes move only about 10 degrees sweep. Other times, it almost is ratcheting. Moves, pauses, moves again. Same situation with stalk switch in all positions.

Back Ground: The car is new to me. Purchased w/ no start/no run condition. Returned to running via through cleaning of all grounds, fusible links, starter & J460 modules. Was able to VCDX clear all codes (except aux. heater module communication & after market radio no comms). approx. 200 miles put on the car. runs fine, no return codes. Finished putting it back together put the cowl back & wipers back on. Only about 10 deg. I figured it was a corrosion issue, pulled an assembly off of a buddy’s parts car, cleaned & lubed & installed. The problem remains. The hood is down & latched. It does not appear to be related to the hood open switch. I tried searching to no success.


Is this a lingering ground issue? Coding issue? Faulty motor? Any & all suggestions appreciated. Thanks in advance.

 

[Bob S.]

Someone responded to my post on Vortex that got me back to the basics. in summary, I got it resolved. I went back out to the shop, removed the original assembly that was currently in the car, disconnected the linkage from the motor. Turns out that motor & module short cycled by themselves. Either the seller was wrong about them working, or the mechanics that were working on it before did something to damage the attached J400 module. So, I did the same with the assembly off the buddy's parts car. It worked fine without the linkage attached. So, I reindexed, tested, worked fine & reinstalled & is working. Interesting that both had the same symptoms with different causes. I was definitely overthinking it. I wish I could have those few hours back.

 

[Bob S.]

On addendum & update for those who may be reading in future diagnostic searches. Turns out it was not quite that simple.

The problem came back a day later. In a bit more diagnostic time:
- The wiper signal from module J519 to J400 wiper module cycles high/ow approx. 10.2 & 9.5 VDC as pilot signal for wiper direction.
- Only the violet/white signal wire comes from J519. The wiper 12+VDC comes directly from SB fuse box top in the engine space.
- The ground is internally connected within the main harness.

What I realized way too late was that someone had been into the main harness before me making repairs (unknown reasons). I found a poor/loose crimp connection in the bin ground wire, established the connection w/ new heat shrink butt connector. All returned to normal.