I don't know quite what's going on, but maybe I've got something backwards. This is a new engine swap, 460 into a 1985 F250, originally had 351w. The first starter I purchased would bind against the flywheel, so I took it back and got a 70's era (78 starter with the starter mounted solenoid. It doesn't bind on the flywheel. The original (351) wiring required the use of the firewall mounted solenoid. Apparently, this one does not need the firewall mounted solenoid, although I've attempted to wire it through that solenoid.
The problem I have, is that it is turning the engine over SO slow, and using so much juice, that nothing good is happening.
What do I need to do to get this starter to work? I'm at a loss right now, and I've tried several different configurations on the wires. Do I ditch the firewall solenoid, and try to wire straight to the starter mounted one, or do I need to rethink my wiring altogether?

On a brighter note, the engine did spin, at least a little.

This is the diagram I followed, since I have the starter mounted solenoid, and the firewall solenoid. I actually copied this from another forum, but I have the same setup, minus the mini starter.

 

I will try to explain this using your diagram. Don't run the wire from terminal B on the firewall solenoid, just run the wire from the firewall mounted unit down like you were using the old style starter, then run a small jumper wire from that main terminal on the start over to the S terminal, this will actuate it when you apply power through the main solenoid. This removes one wire from the mess and actually works fine.

Next thing make REAL sure you have a good ground from the battery to the engine, and then from the engine to the frame.

If that isn't clear let me know

 

It makes perfect sense! Thanks a million, I'm going to give that a shot first thing in the morning. Thank you.

 

And, following your instructions, I eliminated one wire. I'm still having the same symptoms, struggling to turn the engine over, starter getting very hot. The converter is installed correctly, I can spin the engine by the crank snout bolt with relative ease (not easy, but it goes with barely more effort than with the transmission off), but trying to get it going via the starter is not happening. I'm starting to get very frustrated, this truck has been down for over 2 weeks now, and I can't make any money without it.

 

Have you tried cranking it over without the ignition powered up? Your timing might be too far advanced. I know that my engine will barely spin over even cold if I have a bit too much base timing in.

 

LIke I said before double check all your grounds, as well as the suggestion by 82F100SWB to check the timing. But honestly hard cranking and getting hot is often caused by poor or insufficient grounds.

 

I'm going to recheck the grounds here in a few minutes, as well as making an attempt at timing, etc. We'll see what happens.

 

I don't mean any disrespect, but I have the exact same starter as pictured in the diagram, and that exact same instruction booklet, and if you flip a page over in this booklet it tells you exactly not to do the above mentioned circuit because of back-EMF that can hold the starter actuated after you release the key. Because of the inductance in the starter motor windings, wiring it this way will try to hold the solenoid shut after you let off the key and the starter drive will grind into the flywheel.

The Ford Racing mini-starter takes constant 12V to the starter, so the heavy-gauge starter cable that used to go from the hot-in-start post of the fender-mounted solenoid gets flipped to the other side, so that it's hot at all times. Then a smaller gauge wire goes from the hot-in-start post of the fender-mounted solenoid down to the stud on the starter-mounted solenoid. Just like the diagram says. In the end you have two wires goes down to your mini-starter (heavy-gauge hot-at-all-times and smaller-gauge hot-in-start). That is why these mini-starters are risky because you have to run a heavy-gauge unfused hot-at-all times cable down to your frame. I set my battery cables on fire because of this when my starter cable melted to my headers. Be careful. And always have the negative battery cable disconnected when you're working on starters, especially when you're underneath the vehicle.

 

For reference, I'm not actually using a mini starter; I'm using a regular, full sized starter mounted solenoid starter.
I'm still at a loss, however, as I've added extra grounds from the engine to the frame and body, and I'm still having the same issues. The battery hasn't ever dropped below 12 volts while doing this, but this thing won't crank at 12 volts.

 

just as a check, take that starter off and up to your autoparts store and have them test it to make sure IT isn't the issue. I realize it is new but that doesn't preclude it being bad.

fmc400 no disrespect taken, but the way I said to wire it was the way that 2 different mine starters I have run were all wired by the manufacture (they both had the jumper wire already done from the factory and the directions cam saying to do it that way, in fact the first time I have ever seen anyone instruct to wire it the way in the above diagram was in this thread) and another racing I run with that has the late model gear drive ford starter used on 92 and later trucks has his wired the way I described (because I wired it I will admit) for the past 4 yrs with no issues. I know the Tilton and the powermaster HP starters use the wiring I mentioned.

 

That's interesting. Thank you for the information. If anyone is curious about the Ford instructions, here is the link to Ford Racing's instructions for mini starters. The warning I'm talking about is on the first page.

http://store.summitracing.com/instru...00%2Da50%2Epdf