CaptainSquirts

iTrader: (3)

When I start my car, the voltage sits around 13.5-14. When I have my lights, ac, and dashcams all on it drops to like low 12's. I noticed when my AC is on, my voltage will drop slowly. It will always be at low 12's and it will slowly drop e.g 12.1, to 12, to 11.9, to 11.8 and so on. This only happens when the AC is on. Having everything else on won't cause the volts to drop slowly. I was having issues with my hard wired dashcam and it would always shut off when I had everything turned on. If I turn my AC off, or headlights off, the dashcam will turn back on. So I might think the low voltage when everything is on is causing the dashcam to turn off.

Any thoughts? Is this normal voltage behavior? Is my AC for some reason draining the voltage?

Biggiesacks

No thats not normal, you probably need a new alternator.

4b11slayer

Anything under 13.4 volts engine on is considered low voltage in my book. You need a alternator

CaptainSquirts

iTrader: (3)

I replaced my alternator with an oem one about 5 months ago... Replacing the alternator sucks very hard.

Biggiesacks

Make sure the connection on the alternator isnt loose

barneyb

It you mean this happens during idle it could be battery. How old is your battery?

CaptainSquirts

iTrader: (3)

I will check the alternator connection and tighten harder.

The voltage drops the most when the car is standing still at idle. When driving today with just AC, dashcams and gauges. The voltage while driving was low 13's. 13-13.4. At idle I want to say high 12's. With everything on and headlights it dropped to very very low 12's or high 11's. At idle, it's 11.5 give or take a couple.

The battery is almost 2 years old, an optima red top.

CaptainSquirts

iTrader: (3)

Ok so the voltage I was noting above is voltage through the cigarette lighter. I put a tester on the battery and with everything on it stays at 13.4 volts when at idle. 14 volts with nothing except the engine and a couple dash cams on. Now from testing from the battery it seems to be pretty decent? Now from the cig lighter, is that norm or not? I do have multiple gauges but I didn't wire the original and piggy backed onto the original plus two dash cams plugged into the cigarette lighter with an adapter. If the gauges are spliced with the cigarette lighter could that be why the voltages are low there?

RightSaid fred

It depends on the idle speed.
You forgot to mention it.

If it's got a slow idle, then it's normal.


If you bring up the revs for a minute or so, the volts should come up.
Volts WILL come up otherwise your battery would have gone flat ages ago.


Alternator output is proportional to RPM and no alternator gives full output at idle.

CaptainSquirts

iTrader: (3)

Idle is about 800 rpms. When driving with headlights and AC, the volts seem to drop slowly(from the cigarette lighter). When car sits over night the voltage from the cigarette lighter seems to be in the 13.8/13.9 range fresh in the morning. Probably was at like 13.8 volts with headlights on and drove to work(maybe like 5 miles) and by the time I got to work it shows 13.5. So confused.

RightSaid fred

Its normal.


The battery hasn't got flat yet.




Main problem is clueless noobs giving out "fake noos".

barneyb

13.6 at the battery usually means 12.5 inside a car due to tiny wiring. Electronics made to work in automobiles should be engineered to work down to 9 volts. Some do, some don't. Maybe look for another power source for your cameras.

CaptainSquirts

iTrader: (3)

Is there a way to wire the cigarette lighter to get more power?

CaptainSquirts

iTrader: (3)

Also I used a fuse tap onto the Gauge fuse under the steering wheel since it isn't a constant(don't want the dashcam running nonstop) and it did the same thing. Nothing else is hooked up to the gauge fuse and had same symptoms with hard wire dashcam shutting off. The hardwire kit has a low voltage shut off when it reaches around 11.8 volts so being tapped into the gauge fuse is going below 11.9 also. Do all the electrical components fuses under the steering wheel all get the same amount of voltage? Is there a powered on fuse that would get more voltage I could tap into?

CaptainSquirts

iTrader: (3)

Welp had the new alternator for about a year and a half and the battery and brake light is starting to show. Still have same voltage issues where the car starts with 14ish volts and slowly goes down to like 13's and 12's with no lights/ac on and with ac/lights on to low 11's to high 10's. After the car is off over night the voltage starts back up at 14 and its rinse and repeat.

So at this point I think it's the alternator (oem) but since I have my original I think I'll just have a place rebuild it, unless someone has an idea on what to try. Replacing the alternator sucks really bad...