Voltage meter

[mo2058130]

It’s been a few weeks now. Volt meter will read between ~11.5v and ~14.5v. The battery light is on but when I check the battery voltage after several days/ week or two if driving the battery reads 12.65(vehicle off). Not too concerned but don’t wanna be stranded either.

Wife’s daily, she’d be upset! [emoji51][emoji51][emoji51]
Any insight would be appreciated.



2005 GMC Yukon XL

 

[mo2058130]

It’s been a few weeks now. Volt meter will read between ~11.5v and ~14.5v. The battery light is on but when I check the battery voltage after several days/ week or two if driving the battery reads 12.65(vehicle off). Not too concerned but don’t wanna be stranded either.

Wife’s daily, she’d be upset! [emoji51][emoji51][emoji51]
Any insight would be appreciated.



2005 GMC Yukon XL

2005 GMC Yukon XL

 

[Fless]

What does the voltmeter read with the truck running? Should be high 13s, 13.8 or maybe more. Battery light is on for one reason or another....

 

[mo2058130]

What does the voltmeter read with the truck running? Should be high 13s, 13.8 or maybe more. Battery light is on for one reason or another....

I’ll definitely check with engine running. Accessories on or off don’t seem to affect it. Thx for the reply.


2005 GMC Yukon XL

 

[Larryjb]

Forget the dash voltmeter and get one of these:
https://www.amazon.com/gp/product/B000EVWDU0/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

So far, the plug in voltmeter seems accurate when I've checked it against my other voltmeters.

Charging voltage (engine running) should be over 14V, but not over 14.7V. Electrical loads like headlights, electrical heaters (seats, rear window) will cause the charging voltage to be lower.

Resting voltage should be 12.5 V, but other vehicle loads even with the engine off may drop this a little. Ideally, you should read the resting voltage after 24 hours. I don't think I've ever had a voltage this good though. Even new batteries can be sulfated on the shelf if they've sat too long in the store.

Voltage with the ignition on but engine off will likely be below 12V depending on what electrical loads are on (headlights, radio, etc).

 

[Larryjb]

Specifically when is the battery light on? Just when the ignition is on with the engine off?

 

[alaska_guy]

I don't know why they put a battery label on those clusters. The voltage being low is actually being read off the alternator not the battery.

Stop by an auto zone etc and have your alternator and battery tested. They do it for free.

 

[wjburken]

As @alaska_guy stated, the volt meter reads what is coming off the alternator. In addition to getting the alternator tested, I would also check the condition of all your power and ground cables and connections. Corrosion can sneak in and cause issues with voltage drop as well. While your getting your alternator tested, might as well have them test the battery.

 

[mikeyss]

The voltage regulator inside the alternator may be going bad. When my alternator started to go bad, I had the battery light come in, and I had a service charging system message. I also wonder if your sensor on the negative battery cable may be going bad.

 

[mo2058130]

Specifically when is the battery light on? Just when the ignition is on with the engine off?

Light is on all the time. Whether the voltage reads 11.5 or 14.5.


2005 GMC Yukon XL