Why is the charge gauge on my 1985 ford f150 reading very high?
After I installed a new alternator in my 1985 Ford F150 about a month & half ago the
charge gauge started to fluctuate, a mechanic friend checked the voltage & said it was
fine. Last weekend my daughter stopped & put gas in,truck would not start. She
thought she had flooded it, did what she was suppose to do when you flood your vehicle
truck still would not start. About a half hour later I went to start truck & it did not start
up right away like it normally did, when it did start a very loud squeal was coming from
under hood & the charge gauge was all the way to the right (past the c). I ended up
having to replace starter. The charge gauge is still all the way to the right, I also put in a
new voltage regulator thinking thats what the problem was. Old voltage regulator was
fine. What is causing charge gauge to read so high?
Some times rebuilt alts and starters aren't working correctly
when charging, the alt. works hard and takes a lot of power to turn ,resisting against the belts, slipping a little to squeal. once battery gains full charge the regulator senses this and backs off the heavy current . you may have a bad battery sending the wrong signal to regulator calling for more amps. volts are one thing amps are another you can have 12 to 14 volts as normal but amps will vary to the needs, lets say 30 to 90 the amps give it a workout. you may have an amp gauge instead of a voltage gauge like most later models have
It's best to recharge a battery (with a battery charger) after a large drain like that. A full day at 6 or so Amps will bring it back up to snuff. If you rely on the Alternator to do the job, you will be replacing it sooner than you had planned. In other words: charging a dead battery with the alternator alone is a great way to bear out a new alternator.