Wiper blades causing dip in power


#1

1987 Ford F150 302 automatic transmission 5 l 120000 miles.

I replaced my ignition switch on the steering column and mistakenly screwed up the intermittent wiper motor trying to take the knob off of it so I replaced it with a non intermittent wiper motor. I reconnected and grounded it correctly but now I tried to use it and every time the blade goes back and forth it dips the RPMs while idling by about 200 and makes it sound like it is trying to stall. The headlights radio heater or air conditioning do not cause any type of power surge like this. It’s almost as if it is reverse revving the engine. I only got the non intermittent motor because I didn’t have the money to get the intermittent one. I don’t know if replacing it with the OEM motor will fix it or if there’s a way to troubleshoot it. This sort of thing is beyond my knowledge if it is due to faulty wiring.


#2

Sounds like this motor is drawing way too much power. Does it have the correct fuse?


#3

A new one will set you back about $50-$60 plus core charge if you don’t send back an old one.
https://www.rockauto.com/en/catalog/ford,1987,f-150,5.0l+302cid+v8,1121724,wiper+&+washer,wiper+motor,8824

I’m not totally convinced that that the motor is the culprit though.


#4

The fuse is correct. It’s not the wiper motor on the windshield, but it’s the motor that controls the wiper (the one one the dash that you turn it on and adjust speeds with).


#5

It’s actually called the “wiper switch”…


#6

Seeing the 2 different switches require different electrical plugs, I’m going to guess you didn’t wire it correctly.


#7

Intermittant vs standard, the wiring harness is configured quite differently. For standard there’s no interval timer module wired between the switch and the wiper motor. You probably still got that hooked up in between your switch and the wiper motor. For the standard configuration, the switch and wiper seem to be connected like this from what I can tell.

switch — wiper motor
B – run (red)
D – park (black/pink)
C – Low (white)
E – High (dark brown/orange)

My advice is to disconnect everything until you can obtain the correct switch for the intermittent function. Otherwise you stand to cause expensive damage to other parts of the electronics, including possibly starting a fire.


#8

Ah gotcha. Thank you, I will certainly be getting a new one that is OEM. I appreciate everyone’s help