Hotwire for wiper/washer pump
 

I got an external washer pump I need to hook up. According to the truck's wiring diagram there are 3 wires going to the wiper switch. Lt. Blue, Dark Blue and Blue. Am I right in thinking the Lt. Blue wire is the hot wire for the washer pump?

Re: Hotwire for wiper/washer pump
 

The three wires hooked to the wiper button are all used for grounding. The wiper and washer pump are powered off of an ignition source so when the key is on the power is on.

To use the switch with your pump it would be a simple matter of running a hot wire off of the fuse panel. You can plug it into the "Unfused Ignition"
section and set up an inline fuse if you want to fuse it.

Then you could extend the wire for the washer pump switch to the new pump so that when you pushed the button the pump would work.

There are two wires on your original pump, 1 is power, (yellow, I believe ) and the other is the wire that you want to extend to your new pump.

Jim

Re: Hotwire for wiper/washer pump
 

I found that out by accident. With no switch and the pump tapped into the light blue wire both the wipers and pump were going with the key on. If the switch controls the ground, should I hook up the ground wire of the pump to the switch and run a hotwire to the pump? It seems to be doing something, but I won't know for sure cause I had to order a new switch because the made in Taiwan switch self destructed when I pulled the connector off the back.
Edit: Reread your post. So is the other wire on the original pump hot or a ground?

Re: Hotwire for wiper/washer pump
 

Found another thread. Jeez I even posted on it. :crazy: It seems I should splice into the hotwire going to the old pump. Other wiper/washer thread

Re: Hotwire for wiper/washer pump
 

At least you are doing it the smart way by going with an external washer pump. Not me!!! I had to replace the old pump with a new replacement. I would rather pull and rebuild the motor than do this again! I couldn't reach the pump mounting screws. I dropped the steering column, removed the dash panel, radio, a/c and defroster ducts and glove compartment. Reaching the screws on the pump was almost impossible. Finally got it and then had to remove the cowling between the hood and windshield to replace the hoses and clean the nozzles. I love to work on my truck but this was no fun. NEVER AGAIN!

Re: Hotwire for wiper/washer pump
 

I hear you, that's why I'm doing it this way. Just waiting on my wiper switch to come in.

Re: Hotwire for wiper/washer pump
 

Success. After a couple of hours of trial and error I got it to work.
Power wire from external pump to yellow wire on front of factory wiper motor. Ground wire from external pump to middle blue wire on wiper switch. I was losing it for a while trying to wire it to the factory washer wiring. Tight access up there. External pump works off of the factory switch.