98 windstar front wiper not stopping

[jensener]

Even if I turn the switch to the lowest position (supposed to be off), the front windshield wiper just keeps wiping. I have to pull out the fuse to stop it in sunny days. Any suggestions are appreciated.

[thscott]

Same thing happened on my 1999. I ended up having to have a new wiper motor installed. Check the relays and fuses first.

[jensener]

Originally Posted by thscott

Same thing happened on my 1999. I ended up having to have a new wiper motor installed. Check the relays and fuses first.

Thanks a lot for the info. The relays and fuses are all fine. Do you have a detailed info on how to change the wiper motor?

[Selectron]

I've sent you a PM with a link which should contain enough information to enable you to do the job.

I had a look at the wiring diagram and it isn't a nice circuit to be having to work on at all. The wiper switch doesn't pass current in the conventional sense of feeding current to the wiper motor, but instead the switch contains a bank of resistors, with a different value of resistance being switched into circuit depending on what function is required - high speed, low speed, any of the interval delay settings, or the washer function. Even the 'Off' function is determined by a resistance value. The Generic Electronic Module (GEM) senses the value of resistance in the loop through the switch and it then controls any of three relays via its output terminals - the Windshield Wiper Speed Relay, Windshield Wiper Dynamic Brake/Run Relay, and the Windshield Washer Pump Motor Relay. The relay coils are all fed with 12V when in ACC or RUN, and the GEM is responsible for switching the low end of the relay coils to ground, as required, to activate them.

Not a good circuit to work on with less-than-adequate documentation, and the diagram I'm looking at falls short because the GEM is just shown as a box with inputs and outputs but no indication of what's happening internally.

Given the time, inclination and the patience, it would be possible to unplug the multi-function switch and check that the resistances across the three terminals correspond with those indicated on the diagram when the switch is at its various settings. Unplugging the relays and checking for 12V at the high end of the coils and at the input to the switched contacts would be easy enough but I don't think it would achieve much. Of more interest would be what's happening at the low end of the relay coils, to see if the GEM is switching them to ground in the expected manner. However, if that produced any apparent anomalies then you wouldn't necessarily be any the wiser because no details are given on how exactly the GEM is supposed to function.

You might want to just go ahead and take a chance on replacing the wiper motor, but if you want to discuss the circuit some more before doing that then let me know, and the wiring diagram is in the link which I've sent.

[jensener]

Thank you so much for your kindness. I really appreciated it.