Plunger won't stick
 

I bought a 1989 Ford Diesel F850 Dump truck, after my 1985 got stolen. Truck has 38000 actual miles, clean, 6.6 diesel. We test drove, runs great, shifts good, tight truck. The man owned a construction company, business slow, was selling some assets let it go for 4grand. This truck has cost me five hundred dollars, and we still can't find the problem. I've changed fuel filters, oil filters, bought two new batteries, a new alternator, fuel solenoid. I can't find a wiring schematic on the engine. The fuel solenoid engages, but when the key is in run, it drops.
I can wire to a twelve volt supply, it does fine, but I can't turn it off, and it runs down the battery. I know the black is ground, White is crank, but the red has zero voltage. I can tell they had problems with electrical system, wires are spliced and jumped. Real mess. Does anybody know how much voltage should be on the red wire coming off the solenoid? Where does this wire get it's power supply? It appears to be going to the ignition, but someone told me, this wire should not have 12 volts. I'm a new man on board, sorry if this was discussed previously.

moved for better exposure

why moved here? it is a 6.6 ford straight six diesel. not a 6.9.

you cummins guys should be able to answer that question, his FSS is a three wire, just like on the p pumped cummins.

Im guilty of reading it too fast since it was in the into section... :ouch: but all its doing is pulling up the fuel shut off lever? If thats the case you can run the 12v power to a toggle or just buy a choke cable and make a mechanical shutoff.