1979 F100 won't start after overheating
 

I have a 1979 F100 Ranger Lariat with a 351M engine and automatic trans. I am going to lay out the story that led to the truck not starting. I hope it is not too long. While towing a friend's chevy truck about 40 miles to his house my truck overheated. My pressure radiator cap failed. After the truck cooled back down and added coolant I tried to start the truck. The alt, brake and seatbelt lights came on but the starter didn't hit at all. I tried moving the shifter to neutral no luck. After going back forth another couple of times I tried in park again nothing. We jumped it past the starter solenoid and it started right up all lights normal. I towed the truck the last 5 miles to his house. No trouble during those last miles. When we got his truck spotted where he wanted it I turned the truck off and let it cool back down. I checked the coolant and oil both were fine. Tried to start it with the key and nothing. We jumped the solenoid and it started right up. Drove the truck home nothing unusual in the 40 miles home. Thinking the solenoid was the problem I replaced it the next day. Tried to start the truck and nothing same as the day before. I replaced the ground and hot wire last year they are still in good shape. I wondered if the overheating would have damaged something else that is not obvious. I am not a mechanic mainly a part replacer so if there is a troubleshooting guide that tell me the parts to test and how that would be a big help. Thanks for reading this long drawn out story.

Mike

At the firewall, check the connector above the trans filler; it's a 4prong plug that goes to the neutral safety switch. Then check the switch itself
located on the drivers side of the trans behind the shift selector arm.

I'm thinking either the connector got wet or your switch went out, as per normal, at the same time.... Just to make life easier!

.

You called it
 

Thanks OldStyle. I looked up the neutral safety switch to get an idea what it looked like. I found the connector right where you said. I jumpered the two red/blue wires in the male plug and the engine turned over. Looks like we found the problem. It may take care of the back-up lights I haven't had for years. I priced a switch at Advance Auto for $76, AutoZone has them for $40+ and Ebay has them for around $30+. Does anybody have any experience with the neutral safety switch? Thanks again for the good information.