Ok this is the deal, I just finished rebuilding my engine about a week ago and it has been running fine. 2 days ago i was driving my truck all day and it had no problems. I parked it and came back about an hour later and it wouldnt start (like it had a dead btry), i messed with the wires and I got it to start but as soon as i turned the headlights on it died. After that it wouldnt do anything, i cleaned the btry posts and cables, cleaned the ground wire on the block and still nothing. I went and bought a new start solenoid,voltage regulator and still nothing. The starter is brand new and so is the btry I had the btry tested so i know its not that. All the wires are connected and look good. What gets me is that nothing comes on, no lights, cap light radio, horn, nothing! Does anyone have any suggestions? Please help! And its a 78 ford F150, 351M, 2wd.

 

New motor.... hmmm maybe you painted it real thick, and the ground cable at the engine isnt clean and tight? About all I can think of if everything is clean and tight at the battery and no fusable links are fried. Ive seen some aftermarket cable ends that were so corroded or heavily painted the juice would not flow thru where the wires connect. If you have a multimeter do a continuity check of the cables.

BTW it helps to post model and year.

 

Here's the basic set-up. What I would do is go buy a meter or a test light.

Turn the headlight switch on to create a load.

Put the negative of the tester on the bat negative, and the positive of the tester on the battery positive. You should have 12 volts.

Leave the tester negative on the battery, and put the positive tester lead on point #3 in the diagram. You should have 12 volts.

At point #3 in the diagram you should have one or more smaller wires hooked to the terminal, and then going to some fusible links. These wires are what feed the truck's electrical system. Try to pierce the insulation after the fusible links. You should have 12 volts on each.

Anytime in the above tests you don't get 12 volts, then that is where your problem is. If it all tests good then:

Put the tester positive on the positive of the battery.

Put the tester negative on something metal on the engine. You should have 12 volts.

Leave the tester positive on the battery, and put the tester negative on the metal of the firewall and then the frontend sheetmetal. You should read 12 volts with each ground.

If you are getting 12 volts in all the above tests, it's time to pull the ignition switch and check for voltage there.