I went to start my 1989 F150 inline 6 today and when I tried to start no power was coming to the cab. I mean no headlights, dome light, dash lights, radio, etc. My first thought was the battery cable but upon inspection it was tight on the battery post. When to check the ignition again, I noticed the dome light was back on... truck started and has run the rest of the day okay. Lights and everything seem bright as usual.

Anyone have any idea what this could be???

 

The cables and battery connections are known to give problems. Both my 95 and 94 required an annual cleaning of all of the ground connections and especially the batt terminals. My 94 had a bad cable going to the starter. Check the terminals on the starter relay located on the pass fender too. If that relay needs replacing get a good one.
regards
rikard

 

Thanks, they relay on the fender looks clean. The batt. terminal post may need some cleaning but I've seen far worse. I'll check the starter.

Thanks for your help.

 

Even if they look good they can corrode on the inside. I've had it happen to my truck twice already, once terminals and the the cables themselves.