86 F150 5.0L EFI. 4 speed manual transmission.
I just put a long block into this truck and cannot get it to turn over. After the reinstall, I tried to start it up. I heard the fuel pump pressurize and the instruments seemed normal. It cranked over for a second and when it didn't catch right away I tried again. All I get now is a "click" or no sound at all. The instruments all seemed to die (key on). If I walk away and come back, they will revive but die again when I try to start.
Dead short with key on. Right? I checked all the connections and grounds. All good. I got the same action when i just jumper across the starter solenoid. 12.2 volts on the battery and had it tested at the parts store. Bought a new starter. Took out all the spark plugs. Cranked the engine one several revolutions with a socket on the flywheel. Still nothing. Disconnected ALL of the wiring except the positive to the starter. Jumpered across the starter relay and still nothing!
Oh, tested the starter on the ground and spun like a champ.
I'm no automotive electrician, but I am definitely stumped. Any advice would be greatly appreciated.

 

I know you said you tested them, but it still sounds like a ground issue to me. Starter spins, engine turns by hand, battery is good, solenoid got jumped and behaves the same either way. Only thing left in my mind is ground issues.

I've heard many stories of people getting the wrong starter for their engine/transmission combo and I wouldn't rule that out here, but in those instances I think it usually still spins, it just breaks the bendix in the starter.

 

When I say I checked all the connections and grounds, that means I went to each of the connections, pulled them apart again, looked at the spades and sockets and made sure that nothing was bent or touching anything "extra". I also checked around the connections for missing insulation or twisted wires. I did n't ohm anything out.
As far as a grounding issue, the battery is connected to the block and then to the frame. Another block connection goes to the body (shared with the hood light ground). Those are are all 4 or 6 ga. wires. Another 18 ga. wire comes off the fuel injector harness to the block.
No other wires are in the circuit that I know of. I disconnected all of them.
I even disconnected the wire from the starter relay and ran it straight to the battery. It just crackles when it touches...
By the way, I took the starter back and had it bench tested. It's still good. I also tried a PMGR starter. Same effect.

How else do I check for a "grounding issue"?

 

I read everything you said. You have a dirty or loose connection OR a battery cable that is shorting internally, most likely near the end connection.

I have personally experienced this scenario a few times myself and read about it many times on forums like this.

You just have to keep at it until you find the culprit.

What is wrong in the majority of these cases is the connection between the battery POSTS and the inside of the battery cables that hook onto the posts are dirty. Clean the outside of the battery posts and the insides of the post connection shiny clean. I would check those first thing even if you had them removed to have the battery tested. Also make sure the cables tighten up properly on the battery posts.

 

I don't know if you hit all your connections with sand paper or just looked at them, but that would be my suggestion. If that doesn't fix it and the ignition is good there are a few circuits that could prevent starting. It's possible that when pulling the engine out and putting it back in, you may have accidentally damaged the dual brake warning sensor. Look down on your drivers side frame rail where the brake lines come from the master cylinder into a splitter. You should see a plug there with two purple/black wires. If that pigtail is not making good contact, your truck will not start. The other circuit would be the starter relay circiut, that pesky red/blue wire that comes from your ignition switch to the starter solenoid, but it also runs to whatever distributor controller you have. Ignition module on older trucks, and the Emissions Control "brain box" on a truck like yours. If you have swapped to a vacuum advance distributor it would be going to the ignition module. Did you make any type of wiring changes to your ignition when you swapped the motor?

 

Ground connections need to be clean, bare metal. No paint, rust, or corrosion allowed. A good way to clean them up is to remove the wire, wire brush or sand paper the connector and then the grounding point, and then put the connection back together. You should do this at every single grounding point you can find.

Another possibility is an internally failing wire. What I mean by that is this truck was built in 1986, meaning those wires are 31 years old. Sometimes the wires become brittle and break internally. One of the first things I did when I bought my truck was clean all the grounding points and cut new power and ground wires for all major connections (battery, starter, solenoid, alternator). Long term plans for mine include a full re-wire.

 

Thanks for all of the suggestions guys. I work long shifts and haven't been able to get back on to it since my last post, but I will wire brush, scrape, sand and spray with cleaner every wire in that circuit as soon as I get back out there. I'll also check the ends to see if they have corroded or frayed under the insulation. I can heat shrink anything I cut open. I'll also check the brake sensor and starter relay circuit too Yardogg77.
I'll post again when I find the thing that makes it work!

 

I agree. Anytime you have a vehicle with 30 y old wiring, even 15 year old wiring, it's best to give it all a good once over. I have a 1986 also, and I pulled my wiring harness and checked everything before I even started it. I'm not done yet. Now that I know what's in there I plan to find a wiring harness in a wrecking yard from a vehicle that had all the options, then I'm rewiring it using the two harnesses from bumper to bumper. I hate the routing of the wires under the dash, the location of the fuse block, and of course I need to add some modern features too. Crappy wiring pisses me off....

 

SUCCESS! I think this forum is great for troubleshooting. The thing said about cutting new power and ground wires sent me back around the circle again. I bought a new positive cable and one of those battery post/connector cleaners and started back at the battery terminals. Apparently, my old battery post cleaner was worn out, at least, the male part of the brush was worn out. I cleaned the negative terminal and reattached to the post, jumped across the starter relay again, and it spun the engine! I feel kind of foolish, but would not have found it if I had not followed y'alls advice. Thanks for all the help! I put everything else back together and cranked it up. I only had to move the distributor one tooth to get it timed right. Sweet!

 

Oh, and kudos to 88xlt for hitting the nail on the head!