1972 F250 wont crank when atempting to start
 

bench test starter with jumper cables , you could have a bad battery cable check all connections and clean them .

You may have multiple problems, but you can get through them. I hope you have a voltmeter and know how to use it. It will save you TONS of $$ better spent on BEER when you get it running right!

LOL!

Ok, Before you start throwing parts at it, try this:

You say you replaced ignition switch, so I assume it it good. Do you have ~12VDC at the Ignition switch? How about the coil? If so good. (It's OK if it's a little less or more than 12VDC...) If not, possible wiring harness, or a fuse. (Randomly, and just for fun, check the connections including ground to your alternator... Clean them, if nothing else, it'll help you charge the battery when you get it running.)

If you don't have ~12VDC at the Ignition switch, then the connection from the battery to the solenoid, or the wiring to the Ignition switch from the solenoid battery connection is bad. Clean all connections at those terminals first, before suspecting the harness. Got ~12VDC yet?

If you have ~12VDC at the switch, and still nothing in the cab works, look to fuses or other wiring issues. Address it later once you get it running.

Continuing on, do you have ~12 VDC at the Solenoid connection from the key switch when you turn your key all the way to start? (This would be one of the little wires on the solenoid, not the big power wires coming from the battery on one side, and going to the starter on the other.) If not, and with a recently replaced key switch, I'd say problem with the wiring harness coming from your key switch to your solenoid, or solenoid ground. The solenoid grounds through the 2 bolts to the fender well. Clean those connections to bare metal first and try again. Still No crank or start?

If you got ~12VDC at the solenoid from the key switch, then disassemble the high power connections on both sides of the solenoid and at the starter, and wire brush them, re assemble and try again. If still no crank, replace solenoid. Try again. If crank but no start, measure for ~12vdc at your coil while cranking. If ~12VDC is there, clean/check - (Negative) side that goes to distributor for problem. While cranking, with High tension wire from coil removed AT THE DISTRIBUTOR and placed in close proximity to ground, you should get hot blue spark. If not, or spark is weak, could be your coil or improperly set points, or bad condenser. Check points adjustment first, replace condenser second, then coil. You should be checking to see if it will run in between each thing you do. (Gotta save that BEER $$)

Before you got through all this, you should have fixed your problem. I would suggest even after the problem is fixed that you clean connections as that seems to be a big cause of allot of headaches. Think of it as future piece of mind.

Enjoy your BEER!

Good Luck!

re
 

Ya i do have a multimeter i will go thru it thanks i will let you know after tonight when i work on it.