I recently picked up a 76 F-150 with a 360 and I’ve been trying to get it running. I threw a battery in it and if you turn the key to the ON position, after about 6 to 7 seconds it will start cranking on its own. Something else it does is if you turn the key to START, it only starts cranking as soon as it returns to ON. It usually stops when you turn it to OFF but it has stuck a couple of times. I have no clue what would cause this so if anyone has an idea, please let me know.

 

Here’s a clip of what it’s doing

https://drive.google.com/file/d/13KP...w?usp=drivesdk

 

Look closely at your ignition switch.

 

Solenoid as well

 

X2 on possible problem with the ignition switch and the starter solenoid on the passenger side inner fenderwell.

 

As a follow up to what it was doing, now the key does nothing to the starter solenoid but still sends power to the accessories on the ACC and ON positions. Could just be a bad connection where it plugs into the solenoid, I’ll check to make sure. Also when you turn it from OFF to any position, the voltage regulator makes a springy click noise. The wires coming out of the ignition switch also get very hot after a minute or so of it being in the ON position. This whole scenario has me puzzled, if anybody can help for a second time I’d really appreciate it.

 

There is only one wire that legitimately gets hot after you turn the key to ON (but not in ACC) and that's the Red w/green ignition coil's resistor wire. It gets hot by it's design, and is usually packaged separately from the rest of the wires, at least for part of it's run, for this reason.
If any other wires get hot, there is potential for a MUCH BIGGER PROBLEM LOOMING!!!! So don't ignore that hot-wire part of your project.

The heat may also be messing with the switch connections even more, which could explain the reason the starter cranks from just leaving the key switch ON for a few moments.
You can determine (or might have determined before the final failure) just where the problem is coming from by disconnecting first the Red w/blue wire from the S post of the starter relay/solenoid. If the problem goes away then the errant voltage is coming through that wire from the switch, or a possible short circuit in the wire, and is not the fault of the starter relay.
If it still cranks with the S wire removed, then it's likely coming through the Brown wire on the "I" circuit (which is normal by the way) but means that the starter relay is defective.

If your starter relay turns out to be ok, DO NOT CHANGE IT! And yes, I meant to shout that. You do not want to put a potentially problematic new part in place of a known good older one. The new stuff is absolute crap!
Sure, you can buy a new one and get a good one, but the percentage of faulty ones is so high that you almost stand a better chance of getting a bad starter relay (or two, or three, etc) than you do of getting a new one. Does not pay to replace parts as a method of tracking down a problem anymore.

Aside from all that, like was mentioned already, consider a new ignition switch as high on your list. We can't know the condition of your wiring from here of course, so we have to presume that it's good and that you've checked connections and wires for loose, or frayed ends, or possible shorts elsewhere. If that's the case, then it's sure looking like a failed ignition switch.
Wasn't '76 the last year for the problematic ignition switch that we used to see discussed here a lot in years past? Or was it the earlier switches?

Paul

 

This is working as intended. The ACC and ON both send power out almost the same way.



THIS!!!!

 

Make sure the wires are correctly connected at the solenoid...
The brown goes to the "I" terminal, the red w/ blue trace goes to the "S" terminal.

 

Absolutely! Do that first in fact GasGuzler. Easy to make that mistake and easy to check and correct if necessary.
I did not think of it because you mentioned a delay between turning the key and it cranking. But even with the delay, meaning there might still be something wrong with the ignition switch, it would be a good idea to check the wire colors on the two small posts on the starter relay/solenoid.

Oh, and speaking of wire colors... I mentioned the resistor wire being Green w/red. Well that's true enough for some years over a short distance of it's run, but for the most part that resistor wire is a puke-pink-brown color. But no matter what color, it usually has "Resistor Wire. Do not cut or splice" printed fairly clearly over it's length.

Paul

 

I had found some wiring diagrams before I even saw your reply, that was my problem. My stupidity is unbelievable, can’t believe that this was the cause of my problems the entire time. Thanks to everyone for the help though, I really appreciate it. Everything works properly now, very close to getting the truck running for the first time in 22 years.

 

That's still an interesting dilemma though. The fact that it was delayed between turning the key to ON and having the engine crank is an oddity. It should have cranked instantly as soon as you turned the key, with no delay.
When the ignition switch is doing it's thing and all the wiring good, it's a pretty instantaneous sequence of events.

No matter though, as long as it's fixed! Glad you found the issue and it was minor. You're not the first, nor likely to be the last, to reverse those two small wires.
Can't wait to hear the report that it's up and driving!

paul

 

the voltage on the brown wire is dropped because of the resistor wire...so with the wires switched, the S terminal of the solenoid wasn't getting full B+

 

Small update on the project, I’ve been doing a lot of work to it, the last piece I need to get it running is a new carb, the throttle shaft is completely seized in the body and it snapped off the end where the throttle cable attaches. I threw some fuel down the intake without it and I’m happy to say I heard it run for a second or two, hopefully soon I can find what I need.

 

Thanks for the update. Keep the success stories coming.

The frozen up carburetors seems to be a common theme lately. Yours is the third or fourth I’ve heard just in the last month and a half or so between a couple of forums.