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Discussion Starter · #1 ·
I bought a late 99 (04/99) f350 srw. When I bought the truck the windshield wipers did not work. I changed the windshield wiper motor and the wipers then worked well but Turned on with the ignition and would not turn off with the wiper switch. Also the wiper fluid pump turned on with random positions of the wiper switch. However the turn signals worked just fine. So I decided to replace the multifunction switch with A new one from autozone. The windshield wipers then worked just fine with the switch but the left turn signal came on when the truck was given power even though the switch was in the off position and would not turn off with the switch. the right turn signal would not come on at all although the hazards worked fine. So I decided to try to replace the multifunction switch with an OEM one off another 99. When I plug the new OEM multifunction switch in I get the same problem. The left blinker comes on and won’t turn off but the wiper controls work great. I don’t understand how the two switches are identical but one fails to control the windshield wipers properly and the other two (which I assume work properly) cause the left blinker to come on and can’t turn it off.

also I don’t know if this could be related but the windshield wipers will not turn on until the fuel pump is done priming.

Any suggestions would be greatly appreciated. Thank you!!!
 

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Electrical gremlins are so much fun to work with. If I remember right, there is a cam on the shaft that de-activates the blinker. Is yours intact?
 

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Discussion Starter · #3 ·
Electrical gremlins are so much fun to work with. If I remember right, there is a cam on the shaft that de-activates the blinker. Is yours intact?
Thank you for the reply!

the cam on the shaft looks fine. I have the steering column apart. All the wires appear to be in the proper positions in the plug that goes to the MPS according to some wiring diagrams I have found although there aren’t many online to reference that I can find. None of the wires are torn or backed out of the harness. Since I have tried two new MPS that have the same left blinker problem when I plug them in but the stock MPS has only the wiper problem, it makes me think the problem is differences in the switches themselves which I’m still baffled about since all three switches have identical part numbers. It’s almost like the new switches are completing a circuit they shouldn’t be but idk.

the only other thing I can think of is maybe the GEM module is doing some wierd things with the new MPS but that’s really low on my list.
 

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Discussion Starter · #4 ·
I have tried two new MPS that have the same left blinker problem when I plug them in but the stock MPS has only the wiper problem
wait grdutjyt so you have had the exact same problem? What was the year of your truck? And did you ever find a solution ? Maybe it’s a specific year issue?
 

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Can you see the pawl that is on the steering column that cancels the turn signal when you turn with the horn pad off?

I know on older vehicles you can.

If you can I'd get the front tires up off of the ground and with the turn signal on I would turn the wheel and see if you can see the problem.
 

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grdutjy is a spammer and his posts have been deleted. He's one of those guys who copy part of someone else's post and repost it. (n)
 
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