Hello. I've got a 1984 F150. Recently, I've noticed some strange electrical problems:

Most of the time, the truck starts up fine, and all systems (ights, wipers, radio, gauges, heater) work fine. Lately, this has degraded. Last week, I'd start her up, and the only electrical thing that works is the emergency brake light above the gauge cluster. Everything else is dead.

This week, I drove the truck around the neighborhood, and after 3-4 minutes, all the electrical systems popped on and worked fine.

This morning, I started up the truck several times. Various electrical items would or would not work each start - for instance, the wipers and headlights would work, but not the radio, heater fan or turn signals. When I turn the key to start, I can hear the fan starting, but as the engine starts, it cuts out.

The battery is charged. All the fuses are fine. Do I have a wiring short somewhere? Is this an alternator problem?

Also, don't know if this is related, but 90% of the time, she starts up fine. The other 10%, I turn the key, and get a sort of whining sound. After a couple of tries, it usually starts right up without a problem.

Any input would be much appreciated!

 

i'd say ignition switch bad, prob wore out. my 2ct.

 

I'm a neophyte here, and am just getting into do-it-yourself-work. Would a bad ignition switch account for all the other electrical oddities too, or just the intermittant starting problems?

 

what the switch does is connect constant power from battery
to accesories and also crank.
i mean all your acc, ie,heater blower, turn sigs and such must go thru the ing switch.
i wonder if ya jiggle it some when its running if some stuff works or not.
the only other thing i can think of would be a fuse link- underhood
around starter selonid i think-.
if that was the case 1 of the 2 main constant wires that run to ing switch may not be feeding the accesories.
some fords had recalls on the switch but i don't know if this applys
to you.

i would get underdash to switch harness and check wires when running with test light, a burnt fuse link is usally easy to spot underhood.
good luck

 

An early truck like yours is famous for the detents not working correctly in the switch mechanism. I had this problem with my 1980, and I got in the habit of wiggling the key a little bit after starting, to make sure it was in the center of the run position.

I am going to guess your starting whine is because of the colder weather. If you have an oil leak down around the starter area, oil and crud get on the shaft of the starter. When a sudden cold spell hits, the oil and crud gets stiff, and won't let the gear slide out all the way to contact the flywheel. This is just a theory, but if it clears up during warm weather, and happens again when its' cold, I would say that 's what it is.

 

One thing to check when you are getting "wierd" problems is grounding. If the ground from the dash to the cab or the cab to the engine block is nor 100% then when you incease load the ground floats above 0 volts and the current starts looking for a place to return to ground. If there is corrosin on the ground strap then it may get better and worse randomly. It WILL find a way to get back to the battery but you may not like the path it takes.