This is my first project in about 20 years, I was too busy raising kids to play with a truck. Anyway, I have a 1993 F150 XLT, full power, air , cruise, etc. Today, I noticed that the alternator gauge was showing that it was overcharging. It was fine the last time I remember looking at it. The only problems I noticed was a skip when idling and when I unplug the IAC, the idle remains the same. I'm not sure, but I believe all the problems occurred at, or about, the same time. Could this be the voltage regulator? Would it cause any/all of these problems?
Has anyone had a similar problem, or heard of one similar? If so, what do you think is going on?
I'm not great with electronics, because they weren't as popular when I had a vehicle that I played with (meaning the 70's and early 80's), so I need a little advice on this one. Actually any advice would be great.
TIA!

 

Sounds like 2 problems to me. Check the voltage with a meter adn make sure its overcharging, if it is, Its probally the voltage regulator.

As for the skip, how long since its had a tune up? How many miles on it?

 

This is a project truck that I picked up from a friend. He neglected it until it would barely run, then he let it sit until his wife made him sell it. I picked it up for a song. On the way home the timing chain went out and I was able to limp home. I replaced the timing chain, gears, thermostat, wires, plugs, dist. cap, rotor, oil change and new air filter.
It runs great, or did, now it runs great until it gets warm. Then I have a skip. Tracing the skip led to the IAC, which does not affect the idle, either cold or warm, regardless of the rpms.
The truck has 294k miles, but the motor was rebuilt about 75k miles ago, because of a hole in #8 piston. Yes, I repositioned the PCV valve hose to the vacuum tree on the plenum.
I'm great with the really old vehicles, before electronics, but the electronics aren't my long suit. I was just wondering if the alternator could affect the IAC and cause a skip?
I'll check the output on the alternator tomorrow. It was getting dark so I had to quit for the day, today.

 

Checked the alternator this morning and, yes it was overcharging. Went to Autozone and picked up a NEW alternator. It's no longer overcharging, but the IAC still doesn't affect the idling. I unplugged the IAC when cold and started the engine. It ran fine. When it warmed up, it started skipping. Plugged the IAC in and the idle and skip remained the same.
Back to the original question:
Can an overcharging alternator cause an IAC to go bad or stop working? Or, does the IAC really matter, since the truck drives fine on the road. It only skips when idling, regardless of RPMs or whether or not it is in gear.
I would simply love to find out the answers. I don't care what the problem is, I just want it to idle smoothly.