I have 79 truck finishing up a complete frame off, installed a new wire harness(factory) and testing all equipment in dash. all works but the wiper motor. new motor and switch. replaced twice. the washer pump works but the wiper motor will not turn.

 

Welcome to FTE. Do you have standard or delay wipers?

 

delay wipers

 

First, make sure the orange w/ white trace wire has 12v and make sure the switch itself is grounded. The original switch grounds through the metal dash. Replacement switches have a short ground pigtail because the same switch is also used on later models that had plastic dashes.

 

Did you put the ground strap back on the wiper motor? There should be a copper strip under one of the mounting screws that grounds to the body. If it ain't there, wiper motor won't work.

 

groud strap is in place, I have not tried to put a separate ground yet.

 

ok new 2 speed motor, new switch, with delay?? but it does not have a box??both motor and switch are grouded and 12 volts are coming to the switch. when I push in the switch the washer works!! could it be the missing box between the switch and motor???

 

Yes, you're missing the governor box.

 

where can I get one ???

 

Craigs List, E-bay, salvage yard.
As far as I know, no dealer has any left in stock.
I see them on e-bay quite often

 

If you don't have to have delay wipers, all you need to do is get the standard non-delay switch and plug it into the harness.

 

also I pluged into the original switch that does not have delay and the wiper motor still would not move

 

Check the orange w/ white trace wire for power. The fact that the washer pump works isn't a valid test. The windshield washer receives power from a separate source (white wire w/ black trace).

 

no blown fuses, where is the supply for it ???

 

According to the factory wiring diagrams, the windshield wipers receive their power through the ignition switch and that circuit is protected by a fusible link, not a fuse.
If there's no power at the wiper motor, check the fusible links at the starter solenoid. These are easy to check. The wires will have little flags on the that says FUSIBLE LINK then the size, something like 16 ga. take the wire and "tug" on it. If it feels soft or stretches then its bad and needs to be replaced.
Also, you can go here for copies of the FACTORY wiring diagrams. On the '79 copy, the windshield wiper circuit is on page 9.
1973-1979 Ford Truck Wiring Diagrams & Schematics - FORDification.net