Ok, I've got a really interesting one here.


I thought my washer pump was out on my 09 Silverado 1500. So I got a new one, at 20 bucks, it was no big deal. However, after installing it, it still won't work. The wipers work fine, and when I hit the mist, the wipers move as they should, but no fluid. All wiper settings work, as well as all other functions of that lever (turn signal, brights, etc).

So, I did some quick diagnostics, and now I'm lost

Ran a line from the battery to the fuse for the washer fluid pump. Works!

Pulled the wire connector for the wipers/washer from the steering column, and did some jumping, same problem as when I use the actual switch, the wipers make 4 passes, but no fluid.

My concern is where to look next. I've now eliminated the switch in the cabin, and the pump, as well as wiring from the fuse box to the pump. Somewhere, along the way, the single wire that carries the signal from the switch on the column, it must branch off and send a signal to the pump, but I have no idea where, and cannot find anything that shows me where it is.

The BCM(Body control module) activates the washer pump via a signal circuit that activates the washer pump relay which is located in the UBEC(underhood bussed electrical center). Check for a ground output from the BCM on circuit 2268(orange wire) at the UBEC, terminal location for this circuit is at the UBEC connector X4 terminal A3. If the ground is there when the washer is activated the most likely cause is the washer relay. If there is no ground at the UBEC then check for ground output at the BCM connector X4 terminal 15. Bad this is if it is the relay the relay is a PCB(printed circuit board) relay and cannot be replaced by conventional means. The UBEC would need to be replaced.