I had this problem, and it was the **** bottoming out on the gauge cluster bezel. I think I adjusted my bezel fitment, but you could also stuff a tiny piece of wadded-up paper, or something like that, into the ****.

Another scenario is that someone retrofitted a later delay/interval wiper switch, and it lacks the washer function?

 

Oh wait, after reading your post again, I would try hooking some battery voltage straight to the new pump motor, and see if it spins over...

 

Use a volt meter to see if you are getting power to the pump motor. If not, and if the fuses are OK and the wiring looks good, you might need a new switch. Dennis Carpenter has them for $25.00 or so.

What year is your truck? My truck is a '74 year model, it has two different plugs on the back of the wiper switch, one is for the washer pump and the other is for the wiper motor. Later models went to a single plug I think. It is easy to test continuity with a volt meter or jump a wire from a hot source to the plug to see if the washer motor gets power. Remember to use a jumper wire to ground the other connector in that plug to complete the circuit.

 

D0OZ-17A553-A .. Wiper/Washer Switch-Use without Intermittent Wipers (Motorcraft SW-896) / Obsolete ~ Available NOS

1973/79 F100/350; 1978/79 Bronco; 1970 Fairlane/Torino.
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D1OZ-17A553-A .. Wiper/Washer Switch-Use with Intermittent Wipers (Motorcraft SW-1010) / Obsolete ~ Available NOS

1973/79 F100/350; 1978/79 Bronco; 1971 Fairlane/Torino.

 

Had this happen when I put in the intermittent wiper switch, just ran a seperate momentary push button for the washer. Works great.

 

I believe the pin-outs on the two switches are different and you need the correct switch for your system, or be prepared to switch wires. Not having a wiring diagram or switches in front of me I can't get more specific now. I have restored a switch to functioning by liberally hosing it down with spray contact cleaner (getting any decent amount down the shaft is a pain), I have swapped switches, tried the added-momentary switch from the wipers hot lead to the washer, rerun wiring to the washer motor, and replaced the washer motor - all are relatively painless and each fixed my particular situation at the time. Check to see if you are getting juice to the motor - if so your ground may be bad. With both juice and ground good does the motor work? If so, check whether when your switch is pushed you have juice through the harness - if not, start back at the switch. Using the wiring diagram determine which wire from the switch goes to the washer motor - see if your test light indicates juice is flowing through the switch to that wire when you push in on the washer button. Have intervals? Make sure you have continuity on that wire through the interval box harness. If you have juice through the switch out of the harness but not to the motor, prepare to track the break or run new wire. This is all a bit time-consuming but pretty painless.