Sorry none of the suggestions have helped. The problem 'started' (no pun intended) when the starter was replaced. The best guess I have left is the cable going from the relay to the starter is shorted to ground. Maybe got pinched when replacing starter or wound up too close to exhaust, etc. I would not put the new starter in until you make sure the starter is the problem. My first suggestion would be to install a master switch in-line on a battery cable so you can quickly take it out of the system without "arc-welding" over the battery trying to get a cable off. Next remove the starter and fasten it to a bench, vise etc. to bench test. Run a set of jumper cables----one cable from big start post on relay to starter hot post; other one from your engine ground connection to a mounting ear on starter. Use your truck's switch and battery to engage starter. If it stops spinning when you release key then you know the starter, the switch, the relay are not a problem.

 

Sorry you have had such a problem with the 462.... I

Maybe you should get a solenoid for the 426, it may be a heavier duty solenoid and have a stronger return spring to overcome the higher current draw the starter pulls which seems to keep the solenoid energized.

I have a final question before I give up on this one.... does the starter itself have a solenoid on top of it?

 

UPDATE

I removed the starter and had it checked out-perfect. I then discovered something which is really weird. I have the negative battery cable unhooked from the battery. The starter cable is unhooked from the starter solenoid. I can take a test light, hook it to the neg battery terminal and touch the side of the engine block and I get a short dim light in the test light and then it fades away. I then take it off the block and then touch the block again-dim light that fades away. Somehow I have a short somewhere touching the block or body or something that is residual voltage. Somehow that residual voltage must be holding the starter solenoid engaged even with the key off.
Needle in the haystack anyone? anyone seen this problem before and have an idea where this might be occurring? I do not have any wires that are hot or melted that I have found.

BTW,no solenoid on top off starter. only the single cable going to it.

 

I started removing fuses, ect to find out which circuit is shorting out and I found 2 wires hooked together (they are original wires)(black with green stripe) going to main post of ignition switch is what is feeding voltage to the block, ect. Now I need to find out where these wires go.

 

You have electron gremlins running amoke.

The indication of power that fades when you use the trouble light is indication a capacator charging up and is not unusual nor is it a bad thing. Ther are several caps in the circuits and the system itself can act a a capacitor. One is on the alternator system, one is on the ignition system, there may be several in the dash wiring and turn signals. Caps are sometimes used to take a system to ground and if they fail, you can have problems.

After you clean up the extra wires on the electrical system, clean the grounds.

This has gone on too long... time to get systematic in the trouble shooting.

If I was having this problem, I would do this:

First, find the junction blocks on the inner fenders. There may be 2 of them left. They are in the alternator circuits if my memory is correct. Remove them, clean the connectors really well, bolt the connectors together and use the thick insulatin tape and then some friction tape to tape them up neatly. This does away with the nasty junction blocks which is a gremlin home. They are notorious for shorts.

Second. If the capacator is still in the ground of the alternator wiring, disconnect it, clean the connectors at the ground and at the connection to the cap, test the cap. Most of these old trucks already have the alternator cap disconnected or removed. it should be located near the alternator regulator and goes to ground, maybe on the inner fender or the radiator mount. To test it, ground the base and use a jumper from the positive side of the battery to the inlet wire and charge it. Toss it to you wife or a teenage kid, if they touch the wire and base they should get a shock. A safer way is to take it into a dark closet and touch the wire to the base and look for a spark. A spark is good.

Third, get your alternator tested to verify the diodes are not fried. Fried diodes can send electrons everywhere and freak you out, for example, I had an oil light come on and off, then the brake light. Bad diode equal bad bad electron gremlins.

Forth. Turn off the switch key. Isolate the problem by disconnecting everything from the solenoid except the battery. Use a jumper from the battery to the hot side of the coil. This will be your on- off switch.

Take a jumper cable as a hot jumper from the hot side of the battery to the starter cable where it goes to the starter near the solenoid. Start the engine. Kill the engine by pulling the jumper to the coil. Repeat as many times as you want to but remember, you can burn out a starter if you do not let it cool down. But... you also want to test it after it heats up from the engine being run.

This will be testing the starter alone. If you are happy with it, reconnect to the solenoid but leave everything else disconnected from the solenoid.

Fifth. Test the solenoid by taking a jumper from the small connector on the solenoid ground side to ground and take a jumper from the battery to the hot side of the solenoid to kick the solenoid in.

The hot side of the solenoid will be the side where the ignition wire is hot when the key is in start.

Sixth. If you are convinced the starter and solenoid is good, then start connecting the wires back up one at a time to find the circuit that is the home of the big ugle red horned gremlin with green buggers on his chin snd repair the circuit.

Finally, hire a Native American Medicine Man to bless the electrical system and truck.

Good luck,

 

SUCCESS!!!

We changed the starter, went to a flat solenoid (HD), Changed the battery cable to a fine strand cables (less resistance), checked the harness for shorts, ect-found a couple possibles and repaired them. Not really sure as of yet what was actually the problem but will update after I go through all we did and figure out the bottom line.
Thanks to all who made suggestions and gave advice-much appreciated! Jim

 

JX, I'm having the same issue, although it didn't start happening until I replaced the solenoid and the ignition switch.

When it all began, I had a good alternator, but no charge and went to the solenoid first.

Do you have any updates on what exactly caused the issue?

Thank you!

 

Sadly, I had this same problem when putting a "new" starter in. Confident nothing else was the cause, as I recently put all new electronics in... I took the reman starter back to NAPA where they confirmed it was bad; I waited as they trucked another reman starter from a local store and it too tested bad. Yes, 2 reman starters were bad from the store. My theory is the garbage starters draw far more current and temporarily weld the solenoid in "start"; I too had to pry negative cable off to get er to stop engaging (w/ key out of ignition).

With a new starter from China, sold at Autozone, and a new Chinese solenoid, I'm confident my truck will drive for a few weeks (keeping a backup solenoid around for the inevitable).

Sadly, with the only available 80s Ford auto electric parts in Eugene/Springfield area being Chinese garbage, I forsee someone else unexpectedly turning their ol Ford into a hybrid too... wanted to share my experience.

 

Maybe try a boat shop. They have Ford marine starter relays that, while the same design, have to pass more rigorous standards and the one I got from Volvo/Penta is made in the USA.
Haven't used it yet, but I'm guessing it will be a good one.

The more common suggestion for starter relays lately has been to find one in a junkyard. Bound to still be a good one there, and by the time it makes it to the junkyard it's been pretty well proven to work. Usually.
Better yet, get one out of a newer Ford and you're likely getting an OE model that has quite a few more good years left in it.

Paul