73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Electrical => Topic started by: Militiaman55 on October 31, 2016, 05:14:37 pm

Title: Wiper Electrical Question.
Post by: Militiaman55 on October 31, 2016, 05:14:37 pm

1974 K10 Cheyenne


Simple question, hopefully a simple solution!  What would cause the windshield washer pump to operate no matter the wiper switch position?  High, low, off/park all work as they should, except washer fluid is flying at all times.  If I push the switch to activate the washer pump nothing changes, meaning washer fluid still pumps out. It only stops if I turn the wipers off.

Rob

Title: Re: Wiper Electrical Question.
Post by: VileZambonie on October 31, 2016, 05:35:55 pm

Most likely need to replace the motor. Check all of your connections and the ground.

Title: Re: Wiper Electrical Question.
Post by: bd on October 31, 2016, 06:39:59 pm

There is a ratchet wheel and dog that are probably worn out or broken.  Unfortunately the service parts are no longer available, so to maintain the OEM design the wiper motor and washer have to be serviced as a complete assembly.  See the 1974 Service Manual (http://www.73-87chevytrucks.com/techinfo/7387CKMans//Service/ST_330_74_1974_Chevrolet_Light_Truck_Service_Manual.pdf#page=907) for the diagnostic procedure.  Some of the Forum members have converted to a Trico replacement pump (https://www.amazon.com/Trico-11-515-Windshield-Washer-Pump-Pack/dp/B000CB7AVE/ref=au_as_r?_encoding=UTF8&Make=Chevrolet%7C47&Model=C10%20Pickup%7C1998&Year=1974%7C1974&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive) with success.

Title: Re: Wiper Electrical Question.
Post by: Militiaman55 on October 31, 2016, 07:02:33 pm

Thank you gentleman. 

I will go through what I can and hope for the best, replacing the complete assembly if necessary.

Kind regards,

Rob

Title: Re: Wiper Electrical Question.
Post by: Militiaman55 on October 31, 2016, 07:08:54 pm

Well, looking at the Trico replacement pump it appears to operate with the OEM switch.  Given that and the price, I'm going to try it out. 

Thanks for the links bd!!

Rob