1998 F150 4X4 4.6 purchased used 1 mo ago.

I've searched the messages till my eyes crossed. I dont think this is the phantom wiper problem. (I wish it was) Intermittent/ interval wipers work fine when the key is in either accessory or run (engine not running) position. As soon as I start the motor the wipers only will work when in the two continous running speed settings. Driving speed or RPM has no effect. If the engine is running the wipers refuse to work on any of the interval positions. I've checked the connections of the relays, cleaned the switch, and even cursed at it a bit. Is there something else I can check?

Cnynctry

 

the gem module is what controls that. have you changed or added anything lately. or before you used the wiper last. it wouldnt take much to wig out the gem. check all the grounds. mostly the small ones little black wire with green bolt. they are everywhere. behind rh kick panel. under hood. i dont think there is anything to just go and check. just mostly grounds and if you have addded anything at all. or change. good luck.

 

Thanks for at least giving me some direction. No I haven't added anything. Since it's a used truck there is no telling what might have been done to it. But there doesn't seem to be any added acc. Where is the GEM located? Is that the same modual that controls the door locks? Are the locks supposed to lock all doors when you put it in gear?

In search of grounds.

 

Update

I got tired of trying to trace down the gremlins in the wiper system. I took it to the dealer to let them try. So far they have found one bad ground and replaced the multi function switch. They called and said it was ready. As they were bringing the truck around to me they discovered that it still has the problem. It's now at least intermittent with the engine running. It goes back in Monday morning to let them try again. They insist it's not the GEM. Time will tell. At least, the most it will cost me is the $100 deductible on my warrantee.

 

Well the wipers work just fine now. The dealer has traced the problem down to a wire loom problem that went to the speed sensor. They replaced the multifunction switch, speed sensor and 2 wire assemblies. Sometimes it’s worth the cost of letting someone track down the elusive intermittent problem.