Windshield Wipers Malfunctioning

[avid]

Hi everyone, the windshield wipers on my 98 Ranger are malfunctioning. They work only on the highest setting and they do not return to the parked position. Just started maybe a week ago and gave no prior indication of malfunction.

I tried a different multi-function switch and that didn't fix it. I tried swapping the horn relay (identical type) with the two different wiper relays in the power distribution box and that didn't fix it. I checked the fuse in the panel. What is likely happening here? Seems like a similar problem as I had with my ac/heat blower where that only worked on the "high" setting (and the solution there was to replace the blower motor resistor).

I have the shop manual but the pinpoint tests seem awfully complicated for what I suspect is a fairly typical issue.

 

[racsan]

well.... not sure if this is relevant, I had a wiper issue with my ‘94, they would only work on high and wouldnt “park”, I too replaced the multi-function switch and the wiper motor. My problem ended up being a bad solder joint in a relay box under the dash, I forget what it was called but it had to do with the varible speed of the wipers and also had something to do with the wipers stopping at the right spot. I couldnt find the part I needed so I ended up taking apart the “black box” and re-soldered the spot that had not been right. This all being said, the wiper motor and other related parts changed for the ‘95 model year, and may have changed again by ‘98 model year...... but theres got to be something, another module perhaps. at least with the new parts youve already put in you wont have to worry about them for awhile.

 

[1990RangerinSK]

There's another thread on here about wiper issues (recently) - something about the dreaded wipers starting randomly on their own.

That thread indicates that the switch doesn't actually control the wipers. It sends a signal to the GEM (?), that turns on the wipers, and adjusts the speed. On my (ex)wife's 1990 Taurus that had the same issue, the dealer said that there's a relay up under the dash somewhere that is most likely the problem.

 

[1990RangerinSK]

There's another thread on here about wiper issues (recently) - something about the dreaded wipers starting randomly on their own.

That thread indicates that the switch doesn't actually control the wipers. It sends a signal to the GEM (?), that turns on the wipers, and adjusts the speed. On my (ex)wife's 1990 Taurus that had the same issue, the dealer said that there's a relay up under the dash somewhere that is most likely the problem.

This thread: https://www.therangerstation.com/fo...-ford-wipers-spontaneously-turning-on.182748/

 

[RonD]

Yes, 1995 and up Ranger switches don't have direct control for the devices, GEM module and then SJB in 2004 are what runs everything in the cab, these are called body control computers

1998 wiper wiring diagram here

Not a whole lot to it, and not sure what relay under the dash would cause a problem, the Battery Saver Relay is under the dash but it would cause more than just a wiper issue

 

[avid]

Yes, 1995 and up Ranger switches don't have direct control for the devices, GEM module and then SJB in 2004 are what runs everything in the cab, these are called body control computers

1998 wiper wiring diagram here

Not a whole lot to it, and not sure what relay under the dash would cause a problem, the Battery Saver Relay is under the dash but it would cause more than just a wiper issue

Thanks, Ron. Are the GEM modules known to develop problems over time? I can't imagine anything external happened to affect it.

 

[RonD]

Yes, while not at all common, they can have problems, often its just a poor connection at one of the connectors

GEM is located behind the radio, so you need to pull radio out to see it, it will be on driver side and will have Four 18 to 26 pin connectors, so lots of wires, lol, not all pins are used
Unplug each connector and have a look at contacts
The simple act of unplugging and plugging back in a connector can clean it, any time you have any electrical issue do that, before replacing anything, sensor included

In 1998 GEM runs speedometer and 4WD along with cab electrics

 

[avid]

Yes, while not at all common, they can have problems, often its just a poor connection at one of the connectors

GEM is located behind the radio, so you need to pull radio out to see it, it will be on driver side and will have Four 18 to 26 pin connectors, so lots of wires, lol, not all pins are used
Unplug each connector and have a look at contacts
The simple act of unplugging and plugging back in a connector can clean it, any time you have any electrical issue do that, before replacing anything, sensor included

In 1998 GEM runs speedometer and 4WD along with cab electrics

Thanks. I'll try that and see if it corrects the problem.