So first of id like to say im new to this forum but i am in need of help really bad. I was cleaning my 1981 ford f250 and had the radio on i went to move it to the other side of my yard and battery died. i grabed on out of my dad truck but as i put it in i put it in backwards and saw sparks on the battery itself i quickly yanked it off. I know be patient but i was in a hurry. So bassically now the dash has no power to it. the only way it does is when i start it by the solinoid and then once started everything works of the motor. i checked all fuses and fusable links. what else could it be??? pls help this is what i take to school.

 

I did this on my 82 and it burned up a fusible link by the solenoid. How did you check the fusible links? My didn't look burned up when it fried.

Sorry if I'm not reading this correctly, but can you only start the truck via bypassing the solenoid?

 

If there's no power to the cab there will be no ignition.
If there's no power to trigger the fender mounted starter relay my first bet would be a fuse.
(But I only have a fusebox diagram for my '87 truck)

 

The fusible links look like tootsie rolls...there are three or four.
One is tucked under the wiring tape farther out than the rest.

 

I've been creating documentation for this kind of issue. Here's the appropriate section from the Electrical and Vacuum Troubleshooting Manual: Charge & Power Distribution - Gary's Garagemahal

 

Thinlizzy13 i tugged a bit on each fusable link found one that was stretchy and took it apart and it was toast. i replaced it i know have power to the cab but it just cranks over in the on position and doesnt disengage. i replaced solinoid, key tumbler, ignition switch, and none of them fixed it so there has to be a ground somewhere and i have no clue where to even start to look to find the grounded out wire.

 

What solenoid did you replace it with? I have gone through 3 advance auto solenoids in a row. Each one fried as soon as I put it in. I splurged for the expensive one from NAPA and haven't had an issue with it yet.
I'm kinda stumped as to what else could cause the starter to not engage besides the solenoid...

 

Most often a bad cable or corroded connection.
(we've all stripped a cable and seen "the black death")
This causes a low voltage situation,, and since the starter is going to draw xxx watts, it pulls excessive amperage through the relay contacts.