Windshield wipers acting up

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Barb

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2003 Expy EB 2WD front and rear wipers suddenly not working as should. Intermittent works all right front wipers. 2nd speed rear acts, slowly, like on 1st speed. If use 2nd one-time option, works as should. On front, 4th and 5th options funtion as though still intermittent. Everything else seems to be working as should -- power windows, etc. Taking to shop Monday but before go, would like to hear what y'all think might be the problem. Thanks!
 

GAINMOB

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i think mine is going bad...can switch to hi beams now
 

MesaGuy

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From your description ( a little vague) it could be any of these things:

1. Multifunction switch in the steering column (e.g. the left stalk). [But probably is NOT the switch.]
2. The GEM (General Purpose Electronics Module) that takes input from the Multi-function Switch.
3. The rear wiper motor aging and not working well anymore.
4. One or more Wiper Motor relays are dirty or partially failed.
5. The multifunction switch wire harness connectors may have failed, and the female receiptical metal contact could be backing out of good contact with the multi-function switch. This was very common on 1st Generation Expeditions.

The rear wiper motor is a common failure, but would not effect your front wipers in any way.

The multifunction switches do fail, but not really all that often. (Usually when they fail, its the high/lo beams and turn signals that break, the wiper controls in the switch rarely break.

Most of the time, the types of symptoms you are describing are unfortunately that the GEM unit in your vehicle is failing. There is a voltage divider tree circuit inside the GEM that can fail, or the output power delivered into the multi-function switch by a GEM power transistor can fail. The Wiper Control design in my opinion is a bad one. In order to keep the signals count (wire count) low(er) inside the multifunction switch to GEM, the multifunction switch and GEM use a complex "encoding scheme" to tell the GEM what positions the switch is in. That is conveyed in an old-fashioned analog way in these trucks. They use three sets of wires, and convey the position by changing the voltage on the line depending on the switch settings. In the GEM, the a voltage level detection circuit (called a voltage divider tree) is used to "recognize" the voltage setting (e.g the switch setting), and then the GEM commands the front or rear wiper motors to act appropriately, by controlling different signals to the wiper motor relays, and by determing when to "pulse" open those controls for intermittent control.

The GEM is expensive to buy new now (and hard to fine for an '04). You can get them from junkyards for about $50 in CA, but they are time consuming to remove from the junker, and time consuming to swap out in your venicle due to the crowded location in the vehicle (behind the under-dash fuse panel, literally screwed into the back of it.) This also makes it basically impossible to try and diagnose the unit to be "sure" its the problem, before attempting to fail.

As a result, mechanics (good ones) try to first eliminate all other possibilities first, and only replace the GEM after none of the other stuff works to fix the problem.

Order or repair attempts should be:
0. Use a towel, and buy a can of Electronics Contact cleaner at the Autoparts, and spray it into the cracks of the washer button, the rear wiper control ring, and the crack between the stalk at the front wiper twist stem.) Sometimes works and helps, but usually not. But easy to do, costs $5, and you can do it yourself.
1. Replace all the wiper motor control relays. (Easy and inexpensive.)
2. Replace the multi-function switch. (Experience mechanic can do it in 30 minutes, part is about $50 after-market, $150 Ford OEM). Less experience on Fords will require 1 hour, and they may possibly break the wiring harness connectors that attach to the multi-function switch, as the Ford design for the capture/release mechanism on this connector to the switch is hideous, non-intuitive, and a lot of connectors get broken (leading to problems later of the same type you are having).
3. Replace the multi-function switch wire harness plastic connector enclosure (the connector), and transplant all of the connector "pins" (really female contact points) into the new plastic housing. (The plastic connector has small plastic "lock-in" fingers (almost like plastic spring clips) that break when the plastic gets 18 years (or 20+) old. The mechanic has to buy a new connector with contact points, remove all the included contact points carefully using an Exacto Knife (takes time), then do the same for your existing (possibly broken) unit, and then put all the wires back into the new plastic, without breaking any of the plastic lock-in fingers. Can take 2 hours, at shop rates.]
4. Replace the GEM. (Largest cost in labor, and largest cost in part appropriation, and largest cost in part.) If your car is factory and has NO aftermarket alarm installed (they tend to be installed exactly in the way of this repair), then the job can be done in 2 hours. [Remove old one, put in new one. But getting a new one (hard), or obtaining from junk yard (used) is also costly. The GEM lists for $250, and junk yards sell them for $50 (self-pick) to $75, pre-picked parts.

Do in the order above (for ease and cost), but my money is on either the CONNECTOR to the multi-function switch, or on the GEM unit itself. At near 20 years, the GEM units seem to just fail a lot.

I had to replace mine (I did it myself, took me forever, e.g. all day, see y o u t u b e) to fix an issue with my front wiper sprayer. I would press and release the spray button, and the wipers and sprayer would go on, and then stay on for 30 seconds to 45 seconds, instead of 1-2 seconds. Then the problem got worse, and the use of the right turn signals would turn on the wiper (connector problem it turned out, not the switch itself). Had to replace the GEM to fix the long-spray time problem, and the connector and switch to fix the wiper on turn signal issue. (But the switch was fine, it was really the connector).

Good luck.
 
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