I have just inherited a 1989 F-250 with a 5.8L engine. The body and interior are in like new condition but mechanically there are some problems. One is after the engine is shut down and the key removed, something electrical is running. This ends up draining the battery quickly. I'm not sure but I think it might be the fuel pump/s. Has anyone ever heard of this happening?

 

When you hear the noise, locate and thump you fuel pump relay(the green one) to verify its your problem. Noise should stop.Should be under the hood but I dont remember if at left or right Fender.

 

Thanks for the help dro man, that was indeed the problem.