monback

After work one day truck was dead- not even a click when key turned, got a jump and started home and the battery light comes on and truck volt meter shows high charge, truck misses out and bucks relative to the battery light coming on. Battery light did not stay on but got brighter with higher RPM and faded to off with low/steady RPM.
Got home and... Battery voltage tests good (Battery tested little over 12v w/vehicle off & just over 14 w/vehicle running), suspected VR was faulty, so had alternator tested and (per the tech) "rebuilt" (assume by $80 price tag that VR was replaced.
Re-installed alt. and checked tightness of belt, and it ran fine and so next day I drive to work all is OK. BUT- Leave my 2nd job later in the evening and when I turn on the lights the engine revs up, the dash battery light comes on, and repeat of same pattern of missing out/bucking with gauges going haywire. As long as I don't rev the engine the battery light is off and it runs OK, but the voltmeter still reads high & a flip from dims to brights and the meter bumps and I get a surge in the headlights.
Where do I start to determine where my problem is?

monback

Nobody?

monback

Glad I figured it out with the help of the tech from XXXX Service. When I called about the repair made to the alternator, they asked me to bring it by anytime and they would check it out. Said leave it on the truck bring the truck by and we'll see it in operation. We won't charge any more for issues related to the alternator. Tech asked did you check the battery ground terminal for corrosion etc? hmmm I did look at it and the negative looked good to me. Feeling stupid for not knowing the corrosion on the terminals could be a cause for SPIKING VOLTAGE- corrosion usually caused me to have low or no charge to the battery and not starting problems - Instead of taking the truck in I decided to check the terminals, I asked my Dad to come over and clean the terminals for me while I was at work. He did so and said the POSITIVE terminal was really corroded underneath the clamp. Since the cleaning of the terminals, I've driven it 2 days with NO issues regarding the voltage spiking. A few more days and I'll be sure that my Dad's handy work did the trick. Turns out the techs clue may have been the solution. IF the problem STAYS gone -I'll call him in a few days and report that the battery posts were cleaned and that fixed it and thank him for that tip. ( and ask if I really needed a voltage regulator replaced or did they assume that it was bad) Out $80 for not knowing battery post corrosion would have the unexpected (by me anyway) affect of causing voltage to spike and embarrassed to not KNOW that would be a possibility. Never imagined I'd stump the panel. Lessons learned- battery posts corrosion causes more than one adverse affect and patience is rewarded. Hope someone else gains from this experience! Will reply to my own post again if the issue returns.

memoniz

I never heard of anything like that, but I do have issues with my electrical system. I think my alternator is fried now. Any problems since?
Thanks

monback

[QUOTE=memoniz;3083931]I never heard of anything like that, but I do have issues with my electrical system. I think my alternator is fried now. Any problems since?
Thanks[/QUOTE
No problems since. Yes I was surprised that I got zero response, but as I said I stumped the panel. One of those moments where you assume the problem is more complex than it really is. Discovered an affect I had never seen related to batt terminals. Assuming the corrosion made the regulator think it needed to produce a greater charge. Not smart enough to know the how or why of that theory, but my logic figured it that way. The only disappointment was in spending $80 on a voltage reg repair I probly didn't need. Just one of those hindsight 20/20 things. All is well and thanks for responding.