Having problems starting my truck
 

Hey, I have a 1978 f150. I was having trouble starting it a little bit ago. I'm pretty sure it's bad wires somewhere. Just wanting to know if I can get the parts while I'm in town today.
I finished putting in a gas tank and swapping out the fuel pump. It started up. Then the headlights died. Side markers had weak lights and brake lights wouldn't work. I killed the truck and ever since then, no response when turning the key.
starter doesn't engage. Receiver doesn't turn on. Lights don't work.
If I turn the key backwards though, the receiver will turn on.
Battery charge is good. And I would think the problem was the wiring behind the ignition cylinder, but the lights aren't working either. I thought the fuse link burnt out on the battery cable, but I replaced the cable and no change. Anyone have any idea what the problem would be?

Take your battery cables off of the battery posts, clean the outside of the battery posts and the inside of the battery cables(clean everything well) and attach the cables securely to the battery posts. May well solve all your problems.

I just went through this myself. Look at the larger yellow wire by the battery that is part of a 4 wire connector. Notorious for corroding, and eventually overheating. Change the headlight switch, and brake light switch. Check your alternator because it also may have quit from the bad wire connection. My symptoms were I would turn the key, and the interior light and radio came on. If I put my foot on the brake, all electricity cut completely out. Sometimes, I could put my foot on the brake and it wouldn't, but the turning the key to start position would cut it. Then sometimes but rarely it would start. Then I would turn it off and try to restart it and it wouldn't. Funny thing is after the electricity would go out, it would come back about 5 minutes later, and then do the same thing. Whenever you have a weak or shorting connection somewhere, the alternator, and battery will not be able to put all 12, or 14 volts through. This is why the switches are mentioned. All electricity that originates from the battery and alternator, are directed to the light switch, and then back to the engine compartment, to feed everything else. Don't bother looking for shorts, it probably won't work because some of the connection in the engine compartment have 4 to 6 wires soldered together underneath a cylindrical hard rubber sheathing. Also one other very rare area for these problems are the inline fuses most of which are running from the firewall passenger side. Hope this helps, and you can fix this. Took me 3 months. Also as a side note. If you can get it started, unhook the negative battery cable while the truck is running. If it stalls then the alternator went bad. DO NOT BUY A REBUILD! I went through three of them which all were D.O.A. Finally I bought a really awesome one from rock auto that was not rebuild and it was spectacular. It has built in circuit protection so that even if you screw up somehow with connections, it won't blow out on you. It was a power select! Great alternators.