2001 Expedition degrading wiper speed control

[Mizagorn]

Hi all. I have an Eddie Bauer that has been experiencing degrading wiper speed control over the last few months.

Initially the wipers simply wouldn't turn off without some fiddling of the steering column switch. Then it became harder to turn them off, and now the intermittent speed does not work. The wipers are low speed always on, and the high speed works but I can't get them to turn off.

I've been pulling the lower left green fuse from the fuse block inside when I don't need the wipers. Today I pulled both relays that I could find in the owner's manual from the power distribution block (numbers 203 and 303 or something similar if I remember correctly).

Obviously the wipers have no power without those relays, but it at least tells me power is getting through them. I don't know if thay means one could still be bad or not.

The steering column switch has full functionality on all other operations, including signaling, head lamps and rear wiper control.

Is this problem more likely to be one of the relays (or another one I missed) or the steering column control switch?

Thanks for any advice. Glad to be here, first time caller.

 

[JamaicaJoe]

If it is designed like Chrysler, and the symptoms are indeed similar, the motor gets braking action by shorting the motor winding to ground through the normally closed contacts of one of the relays. The problem is that relay contacts get cleaned from the arcing action of the load current. Using the relay contacts to shunt the back EMF of a motor is not enough arc to keep the metal shiny. Try switching the relays if they are identical. That is what I did and it fixed my Dodge Caravan that had flaky intermittent wiper action. Then I replaced the relay with new. This after spending $185 non refundable for a multi-function switch because the Haynes manual had incorrect ohms readings for the various switch positions.

 

[Mizagorn]

Try switching the relays if they are identical.

It's been a long time since I was that deep into mechanical electronics, but what you said makes sense. Your detailed comments and enlightenment are very much appreciated! I'll give the relay(s) a swap and see what happens first. Perhaps my 01 F150 will have the same since the window relay in the fuse block is the same. I'll let you know, and thanks again.

 

[JamaicaJoe]

It's been a long time since I was that deep into mechanical electronics, but what you said makes sense. Your detailed comments and enlightenment are very much appreciated! I'll give the relay(s) a swap and see what happens first. Perhaps my 01 F150 will have the same since the window relay in the fuse block is the same. I'll let you know, and thanks again.

You may have to replace at least one, perhaps both relays to fully determine if this is the problem. It has made me consider taking a second look at my 1st gen's rear wiper system. I pulled the relays because it wasn't parking at all and was draining the battery.

 

[Mizagorn]

You may have to replace at least one, perhaps both relays to fully determine if this is the problem.

Just had a chance to get back to addressing this. Two new relays, no change in operation - low or high with nothing in between. I'll take a look at the switch area next. Maybe a loose connection, worth at least looking at before trying to get a new one.

Also pretty sure I need to replace the security module. I can hear it clicking behind the gas gauge and the power locks operation is intermittent. Unlike the wipers haha

 

[JamaicaJoe]

The GEM/ Body control module sometimes gets rained upon due to poorly sealed windshield at driver A pillar. I did not realize that that mine was totally separated until the windshield cracked. The Safelite tech showed me that the paint had failed and so he had to clean it up (surface rust) and use plenty of primer and sealer. I had in past heard clicking from behind the dash and my drivers window motor would start and stop on the highway. It was kind of weird. Never had any water dripping down that I noticed. That problem has fixed itself.