Another front wipers/GEM/MFS question
 

My 2002 Explorer XLT recently experienced a front wiper failure. Initial indications started a few months ago. When trying to turn the wipers on to the intermittent position, nothing would happen. Turning the switch to low or hi then back to intermittent would allow the intermittent to work OK. Issue seemed to be occasional (trying not to overuse intermittent).

A couple days ago, daughter takes off to meet pals, comes back saying wipers died completely, won't move, won't park, no response to any switch position.

I checked it out and researched some of the relevant threads here. My findings thus far:

Front wiper int/lo/hi positions do not work
Front washer pump works fine
Rear wiper switch positions all work fine
High beam, low beam and flash-to-pass work fine
Left and right turn signals work fine.

I am figuring the MFS is probably not the problem.

Looking in the owners manual it seems that fuse #8 protects front and rear wash pump relays and front wiper motor relay. Since front and rear wash pumps actuate fine, I figure fuse #8 is OK and the pump relays (#4 & #6) are OK.

Fuse #20 protects the GEM and Memory Module. Since I am not experiencing any issues with dash lights, idiot lights, chimes, locks or other GEM associated items, I am guessing fuse #20 is OK and the GEM is OK.

This leads me to relays 54 (run/park) and 59 (hi/lo). Since the wipers will not run or park, I am guessing that the run/park relay is having an issue. I presume that the intermittent function is cotrolled by the GEM based on the Intermittent switch position

Am I missing anything or overlooking some complexity that should change my logic? Is it likely for the MFS to fail only the front wiper portion of the controls?

Any thoughts or comments from more experienced contributors would be most welcome.

An update.

The A/C clutch relay is the same part number as the run/park and the hi/lo relays for the wipers. I switched the A/C clutch relay in for the run/park relay and tested the wipers

No change in problem

I put the run/park relay back in and switched the A/C clutch relay in for the hi/lo relay and tested the wipers.

No change in problem.

I guess I am back to the MFS or the GEM at this point. I will start removing the switch assembly and see if I can confirm a failure there.

My suspect would actually be the wiper control/turn signal stalk. I had issues with the intermittent wipers on a prior 1993 Taurus SHO. On that car I was able to pop the end cap off the stalk, remove the phillips head screw holding the wiper knob, then carefully remove the piece (there's a spring behind it, as well as a brass pin with a spring for the position detent). Once that was off, I was able to clean the contacts for the wiper speed settings and inspect the spring finger contacts. I repositioned the spring fingers slightly so they were rubbing on the circuit board in a slightly different location, put some switch lubricant in there, reassembled, and the wipers were still working great 2 years later when I traded the car in.

-Rod