Hello,
I have a 1987 F150 inline 6 4.9 and I'm having a slight problem.
First off, my starter was acting up. It wouldn't release so it would just sit and turn the engine over but would not stop. I eventually had to disconnect the battery for it to stop. I took it over to the garage and they told me it was the solenoid so I had it replaced. It was working fine for about 2 days and then the accessories stopped working properly, the fan was brutally slow, very dim interior lights and such.

There is a drain somewhere and even when the truck is turned off, the battery drains. I had a new battery installed because my other one was under warranty. I put it in and the truck started fine; the next day the battery is completely dead.

Anyone have any ideas?

Thanks.

 

Well, first I would trace the wires coming off the battery to see if they are grounded out anywhere cuasing a short. Then, if you don't find any supicious wiring, I would charge the battery, start up the truck for just a minute then turn it off. Listen to see if there is anything running with the key off/engine off (maybe a fuel pump, cooling fan running to long, ect.). If you come up with nothing here, I would have your alternator tested. How often was the truck driven before the battery would fail? Kinda early in the morning for me to be thinking lol, or I would have a better answer
Good luck.

 

The new solenoid is either bad, or wired wrong. Take it back to the guys that did it and tell them as much. If you are getting nowhere after that, I would try the 87 forum. You will get electrical input that is more correct for your year vehicle, as opposed to ideas from 32 years of inline sixes in 8 different body styles!

good luck!!