Recently purchased this 1995 f150 xl, 4.9 6cyl Had 65000 miles on it. Previous owner said he had swapped alternator out about two years ago and just recently had issues with the computer so had that swapped.

Woke up the other morning and had to jump it off so started digging. Battery voltage was 20v with vehicle off, alternator sending line was reading battery, alternator looks to be sending out 20v when running. Brought battery and alternator to have bench tested and both were good at two different locations. Still bought new battery since the existing one was 3 years old.

The small stator pin connector seemed loose, so ordered the new pig tail and installed, much tighter connection but same results. Decided to just purchase a new alternator and still getting same high volts. Not sure where to go from here. My gauge cluster is not showing high nor is the battery light on, other when is turns on for a second upon start up. only other thing I can think of is it seems like there is some slop in the ignition cylinder and the buzzer sometimes stays going even with key out and lights off

Any help would be great. Thanks.

 

Tried another DVOM?

What does the current DVOM show if the voltage regulator is disconnected?

 

I haven’t tried a diff. Meter.

are you saying disconnect the voltage regulator while vehicle is running and check volts from alternator?

 

Before you buy a new meter, change the meter batteries out. I know for a fact that older Fluke meters did not show a low battery indicator but when the battery is low, it will read incorrectly. As a Shop Foreman, I had a mechanic waste several hours believing his Fluke was good.

 

+ 1 for trying a different meter or changing the battery on the one you have
Turn headlights on for 2 minutes
Then disconnect the battery and retest the voltage
Generally, a bad connection will make the alternator overcharge or not charge at all
Check the negative battery cable ground at the block or starter
Have AutoZone or someone check the alternator output and make sure it is not "full fielding"
If it was truly overcharging, you would possibly be asking, "why there is acid all over my battery" and "what's that smell?"

 

Well, sometimes it’s the thing you least expected. Borrowed my buddy’s Fluke and all readings are perfect. I suppose if anything it was a good exercises in troubleshooting. Thanks for all the suggestions.

 

You are in a fairly large group that have been screwed by a bad reading from a volt meter. It does hone your electrical diagnostic skills and makes you think more than you normally would [about a problem you don't have].

Hopefully, someone else will read this and save a few hours.