Gentlemen,

You might remember me from my last post, Gremlins, and I come to you now with another request for assistance.

Upon purchasing my truck I noted that the wipers did not function as they should. The action of the wipers themselves was slow, and there was a grinding noise coming from the motor itself. The functionality was as it should have been (high, low, park-etc).

Foolishly, I purchased a new motor without checking the plug and lo received a new WAI WPM2002 with a single six-pin terminal. The original harness has two three-pin terminals. So instead of returning the single plug and purchasing one I could plug and play, I went in for a duralast 6 pin plug adaptor.

Here begins the problem, none of the combinations I've attempted have worked and there is a distinct lack of information available for the new motor. The literature I have come across notes that the red wire is constant power (indeed it does get 12V on ACC), the blue/orange wire is high (12V on high), black/pink is park (0V), and white is low (0V on low). The other two I presume are both grounds as they are both black and neither demonstrate voltage but do ground the red wire.

I turned to AI (withhold judgement, I was desperate) and made little progress.

The pin diagram it provided got me as far as some motion from the wipers, but sporadic, short, erratic bursts that did not correlate to any position of the wiper switch.

As I stated earlier, the original motor retained appropriate functionality but lacked performance and sounded like a dice game in alaska.

My question to you fine people is:

Has anyone come across a definitive diagram for this specific connection? I can't imagine I'm the first person to make this swap.

Is this vehicle (90 XLT Lariat) equipped with a wiper control module and is it likely that this is where my problem lies?

I'll provide any test results that are requested and as per my last post I'll try to write up a specific solution for others once this is solved.

Thanks in advance!

 

Maybe these will help?!

fyi, Gremlins 2 was my favorite. The professor was hilarious!

 

Does your truck have intermittent, low and high?
or does your truck have delay, low and high?

you have the wrong wiper motor, and you are missing the control module and switch.

Just like pretty much ANY electrical or electronics part, you need the same replacement, not something different.

Your well on you way with graduating gremlin101 .

 

wwhite,

Interesting suggestion...I don't recall seeing a governor underneath the dash when I had it apart yesterday...I'll take a look tomorrow. Why would it matter whether the trim has interval or delay, to my rudimentary understanding the motor itself is simply a recipient of signals and actuates appropriately. Whether there is a governor or variable speed resistor shouldn't impact the park switch or low speed setting...would love an explanation. I may go ahead and order another with the OEM two plug orientation but it feels like accepting defeat and I'm not keen to dismantle the whole area to swap the motors again.

thanks for the input!

 

could come in handy! What service manual is that? My Haynes doesn't have much information aside from replacing the wiper motor and descriptions of the wiper switch positions.

 

1990 Ford F150 EVTM

https://www.themotorbookstore.com/1990-ford-f150-f350-truck-bronco-electrical-vacuum-troubleshooting-manual.html?gad_source=1&gad_campaignid=2356102596 7&gbraid=0AAAAAD_v1K_KZtsWCKi1rGk26HYh3KZd_&gclid= EAIaIQobChMIsLj3_Jr5lAMV0ifUAR0XTi-LEAQYASABEgId2vD_BwE

 

if you have intermittent wipers and the module is bad, the new motor will still not work. the module is rite near the wiper switch. about 4-6 inches away. the wires from the switch plug into the module plug, the output of the module plugs into the harness going to the motor.