Voltage meter

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

mo2058130

Member
Joined
Nov 11, 2019
Posts
48
Reaction score
18
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.
77998c2a4861bce0d6b22050990a46f1.jpg


2005 GMC Yukon XL
 
OP
OP
M

mo2058130

Member
Joined
Nov 11, 2019
Posts
48
Reaction score
18
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.
77998c2a4861bce0d6b22050990a46f1.jpg


2005 GMC Yukon XL
1a1af8ea199f02c0ae4d41c49cb8ea3b.jpg



2005 GMC Yukon XL
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
10,255
Reaction score
20,314
Location
Elev 5,280
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....
 
OP
OP
M

mo2058130

Member
Joined
Nov 11, 2019
Posts
48
Reaction score
18
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

Full Access Member
Joined
Jul 21, 2016
Posts
1,140
Reaction score
1,045
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

Full Access Member
Joined
Jul 21, 2016
Posts
1,140
Reaction score
1,045
Specifically when is the battery light on? Just when the ignition is on with the engine off?
 

alaska_guy

Full Access Member
Joined
Dec 29, 2015
Posts
121
Reaction score
102
Location
Alaska
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

Supporting Member
Joined
Dec 26, 2017
Posts
9,709
Reaction score
26,313
Location
Eastern Iowa
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

Full Access Member
Joined
Nov 11, 2011
Posts
1,612
Reaction score
3,002
Location
Longmont, Colorado.
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.
 
Top