went to start my grandpaws farm truck the other day (84 f250, 460, auto, 2wd). and it turn over and wouldnt start, pulled key out continued to turn over, until it died. i think dead battery. swap solenoid in case i burned it up, battery in case of dead, and ignition switch under the dash. still nothing any ideas? i get lights and a click. and if i jump the solenoid it will turn over just fine.

 

You have put some of the wiring on the solenoid in the wrong place. Your symptoms are different than they were before. That's a sign that something you did is not right. Check your wiring, you missed a small wire somewhere or put it on the wrong post on the solenoid.

 

Besides the fact cheap aftermarket solenoids are crap and can't handle the juice needed to turn over a big block, I have a theory about why starter solenoids fail:

Bad battery terminals / cables. If the terminal or cable from the battery to the solenoid is bad, corroded internally, old, REPLACE IT with new terminals and a heavy gauge cable. A bad cable or terminal will cause extra draw across the solenoid terminals and fry them.

1) Get a quality solenoid.
2) Check all your battery connections, terminals and grounds. Replace anything suspect.
3) As Dave said, double check your wiring. There are two small terminals on the solenoid:

One (I think it's the "S" terminal) is the starter signal wire from your key switch that tells the solenoid to engage the starter.

The other (The "I" terminal I think) goes directly to the fuel pump to prime the fuel system while cranking.

Anyway, you don't want to get them mixed up...

Good luck and let us know how it goes.

 

Everything except the starter cable goes to the battery + terminal post of the solenoid.
The small red/blue wire goes to the push on 'S' terminal.

 

"S" terminal for "start"...thanks Ard. I assumed he has an electric fuel pump and therefore the fuel pump wire, but it's entirely possible he's got a mechanical pump and no "I" wire...

YMMV.

 

The 'I' wire was a blue fusible link and found in early vehicles.

Most of this generation incorporate the pink and black wire in the harness.
Not sure exactly when that change was made.
I haven't found it in '85-'86 460 trucks.

But Rep's to you for pointing it out!

 

Thanks for the Reps Ard!

FWIW My 86 / 87 carbed 460 has the 20 gauge blue-gray colored fusible link fuel pump bypass wire attached to the I terminal of the starter relay.

 

That's good to know!

I need to change my thinking on what exists vs what i've seen.

 

Yea starter was bad.. Didn't think so since it would turn over with solenoid. . But it was and I don't have a blue wire just green and black.. so they both go on positive and just one on the other post.. oh and black goes on I and red on s... but just my truck I guess thanks guys..