got a strange voltage problem. i think

[bmk6795 10+ year member]

if you disconnect the batt and you still have the problem then you have something regulating your voltage. my car has a eld, electronic load detector, and dows the exact same thing you are describing, runs at 14.4v for a few miles then drops to 12.5.

 

[black pearl]

if you disconnect the batt and you still have the problem then you have something regulating your voltage. my car has a eld, electronic load detector, and dows the exact same thing you are describing, runs at 14.4v for a few miles then drops to 12.5.

that's about what it seems to do, what kind of car is it. I have 2010 Tahoe

 

[bmk6795 10+ year member]

that's about what it seems to do, what kind of car is it. I have 2010 Tahoe

I've got a 2001 civic but i think it's more common on newer vehicles.

 

[winkychevelle 10+ year member]

Its the voltage regulator. My 07 silverado did the same thing. If you start the car with the system drawing a good bit of current it will keep the voltage up sometimes as high as 15.5v but it drops down once the batt has a good stable voltage.

 

[black pearl]

Its the voltage regulator. My 07 silverado did the same thing. If you start the car with the system drawing a good bit of current it will keep the voltage up sometimes as high as 15.5v but it drops down once the batt has a good stable voltage.

so maybe what was happening was with 2 batteries it had plenty of power and wasn't seeing a load so it was dropping the voltage because I wasn't being used?

 

[winkychevelle 10+ year member]

so maybe what was happening was with 2 batteries it had plenty of power and wasn't seeing a load so it was dropping the voltage because I wasn't being used?

Prolly the newer trucks shut the alts off when not needed to increase fuel milage by whatever little bit it does

 

[Full Tilt 10+ year member]

I was trying to decide between getting a Grand Prix or a foreign car when I turned 16...I ended up getting the Pontiac because I didn't want to fight the regulators and all of that crap that the imports were already coming with. Apparently GM picked up the idea...crap.

 

[winkychevelle 10+ year member]

I was trying to decide between getting a Grand Prix or a foreign car when I turned 16...I ended up getting the Pontiac because I didn't want to fight the regulators and all of that crap that the imports were already coming with. Apparently GM picked up the idea...crap.

Lol yea at least with the new cars during braking youll get a voltage boost to 15.5v

 

[Full Tilt 10+ year member]

Lol yea at least with the new cars during braking youll get a voltage boost to 15.5v

I guess guys are giving brake checks in the lanes then, huh? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[jrdnhsnbrg 10+ year member]

My 2001 Lincoln Continental's ECU has a huge role in voltage regulation, when I start the car it jumps to 14.2 then after idling for a bit usually sits around 13.4V. I want to upgrade the alternator but I don't want to mess up the ECU somehow or have the means to at this point, just started college //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[stephens30228 10+ year member]

I have a similar problem. My aftermarket alt doesn't start charging until 1k rpms. My truck idles at 500 rpms (2005 ford explorer) so at Red lights my voltage driops to 11.6v :/ can't fix it for anything.

 

[hispls 5,000+ posts]

A 12V battery is SUPPOSED to rest around there. God, people are soft here.

The issue is your regulator. Many vehicles will charge at much lower than 14.4 particularly after the car has been running for a few minutes. If this is a problem for you you should bypass the factory regulator and buy an outboard one.