Volt Gauge Bouncing

[drdave81]

I've had an intermittent issue recently with my volt gauge bouncing around/twitching. It seems to happen more under load, but will still move a bit at idle/light throttle at times. I replaced the belt tensioner since it was sticking a bit, and had the 1 year old alternator tested a couple times, no issues there. It will read normal but occasional twitch or bounce low, dipping under 12V a bit as I drive. I know it's actually the charging system since my headlights will dim as it happens. The blower motor for the heat will bog down a bit too. So it's not just a gauge issue. Battery is only a couple months old, and the cables from the battery to alternator, as well as battery to chassis and battery to engine are all new (Big 3 upgrade). Connections there are all tight. My next step is to chase down every ground, but I was wondering if anyone else has run into this and what they found with it.

 

[OR VietVet]

What brand/make is the alternator? Genuine GM or aftermarket and what brand name? Sounds like a voltage regulator problem or possible diode trio problem but lean toward the regulator. How long is the warranty on the alternator? If was a reman alternator, some companies will start their rebuild with testing different components, replace on suspect or bad components and send it out with still old components in it.

 

[drdave81]

AC Delco alternator, if I remember right it was a reman. It was tested twice and both times passed on their bench tester. I thought it would be that too since it seems to be more load dependent.

 

[drdave81]

Just checked, yes it is an AC Delco gold reman alternator.

 

[corvette744]

Just checked, yes it is an AC Delco gold reman alternator.

Replace the alternator tell them your having issues with it.But question how long ago did you do the big 3 upgrade.Did this start right after you did that?

 

[drdave81]

Replace the alternator tell them your having issues with it.But question how long ago did you do the big 3 upgrade.Did this start right after you did that?

I just ordered the replacement one (Rockauto). I did the upgrade months ago, this issue just started a couple weeks ago (I was gone all last week, didn't drive it). I double checked every wire I replaced to make sure none of the connections were coming loose, all are tight and crimped on the wires properly yet. Wiggle test showed nothing either.

 

[OR VietVet]

I have seen, many times, where a bench tested alternator will test and act different than when mounted to vehicle and tested.

 

[drdave81]

I wondered that too. I ordered one, just wondered if anyone else had come across something similar, in case there was something else to look at.
I'd like to limit my time working outside since it's winter and my Camaro is taking up the garage lol.

 

[OR VietVet]

The info I said had to do with your description, what I have seen in my shops, my experience and that you had not done any recent work before the problem started and the
*rechecks you did*. I do hope the new alternator will fix.

 

[Fless]

What year is your truck? Didn't RVC start in 2005?