On a 1984 f350 with a 6.9 idi which wire powers the glow plug solenoid and which one sends power to the fss. Im having a really hard time figuring it out. i thought the purple wire powered the glow plug solenoid but when i put power to the fss the solenoid clicked. So now im really lost i have no idea what powers either one.

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Heres what i got

 

The purple wire is the right wire to trip the glowplug solenoid. It is powered by the controller (long thing standing up behind your driverside cylinder head) you can apply power to that terminal for 5-10 seconds depending on the temp and if the plugs are good and the fss is getting power it should crank.

Not sure what your problem is here. Guessing it won't start so you may have to make your you have over 1/4 tank of fuel and push the valve on the fuel filter housing to make sure you don't have air in the system. You'll have to push it down while someone else cranks it.

 

You can vent trapped air from the fuel filter head yourself if you use a screwdriver; or better yet jumper cables, shorted across the terminals of the starter solenoid. The screwdriver trick won't work though if you have a new style starter solenoid.

 

the truck will start and run fine. but only when i put 12v to the fss. the truck wont send power to the fss. im trying to fix a mess of wires

 

Check the fuseable links on the passenger side fender. If they check out good I would remove the ignition switch next and check that