Alternator and/or Voltage Regulator Issue? - TerrainForum.net: GMC Terrain Forum
 4Likes
Reply
 
LinkBack Thread Tools
post #1 of 24 (permalink) Old 05-24-2019, 08:26 PM Thread Starter
Hero Member
 
Join Date: Jan 2015
Posts: 891
Alternator and/or Voltage Regulator Issue?

I leave my Escort radar detector on the voltage display setting since my '15 V6 Equinox doesn't have a volt gauge. Noticed something odd this evening and need to figure it out before it gets worse or leaves me stranded...


At start up, it's usually showing high 13's / low 14's volts on the radar detector meter and then usually tapers off to the mid 12's while driving. It's still doing that, but now when I'm cruising on the interstate, I noticed the volts are now dropping to around 11.6 and actually dipped to 11.2 at times while cruising at 70ish and the RPM's are just a tick below 2K. When I got in my driveway just now, to just let it sit an idle, it jumped back up to the mid to high 12 volt range. I pulled my volt meter out to verify what I'm reading at my radar detector is accurate, and it seems my radar detector is reading almost exactly 1 volt lower than my digital volt meter, but it's still mirroring how my electrical system is behaving. So that may mean than when I'm cruising and my radar detector is showing 11.2 volts, I'm actually at 12.2, which may also explain why my battery light hasn't come on yet, but that still seems low for cruising down the interstate...



I've already stopped by the auto parts store and had the battery load tested to eliminate it as the culprit and it tested just fine. It's a Duracell battery from Sams Club with free replacement until March of next year. With the way my electrical system is acting, I'm leaning towards the voltage regulator, which still means I need to replace the whole alternator.


One other thing I want to mention is it's now gotten HOT in GA already. It was 93 degrees when all this was going on and we're due to be up to 100 at times this weekend already! My volt meter has always read lower in the summer months than winter.


My '15 Equinox has 107.5K miles on it. It's looking like my next step is to just remove the alternator and have it tested, but that's not really how I wanted to spend my weekend!


Anyone have anything else to suggest? Anyone already done the alternator on your 3.6 V6? It doesn't look to be too bad of a job since it's at the front, not firewall side at least. Any tips if you have replaced yours already? Any thoughts and/or suggestions are welcome! Thanks!

-2015 Chevrolet Equinox SS 301HP V6
-1998 Chevrolet Camaro Z28 400.1 RWHP 6 Speed
BandDirector is offline  
Sponsored Links
Advertisement
 
post #2 of 24 (permalink) Old 05-24-2019, 09:34 PM
Theta GOD!
 
Join Date: Jan 2010
Posts: 9,555
Before replacing the alternator, do some searches on the forum. As I recall, the alternator operation is run to optimize had mileage. This may only be on the 18+, but I think the 10-17also did that.

2018 Equinox LT1 1.5 L 4 cyl, AWD, S/R Cajun Red Tintcoat/Black

2010 Equinox LTZ 2.4 L 4 cyl, FWD, S/R Cardinal Red/Black
RIT333 is offline  
post #3 of 24 (permalink) Old 05-24-2019, 10:49 PM Thread Starter
Hero Member
 
Join Date: Jan 2015
Posts: 891
Thanks! I just did that search and often wondered if my computer did something like that because Iíve seen low 12ís at times I thought I shouldíve been seeing high 13ís or even 14ís when driving. However, the threads I found mention that it happens in the Eco mode on the I4ís, but the V6 doesnít have an Eco mode, so not sure if that applies to the V6.

I found a used alternator on eBay from a wrecked Ď15 V6 with 63K mikes on it and I only paid $45 shipped. Since Iím not getting a battery light at the moment, Iíll wait until the used one arrives, have it tested, and then remove mine to have it tested. If mine is no good, then Iíll only be out $45 to fix it. If mine is still good, then Iíve got a spare I only spent $45 on.
BandDirector is offline  
Sponsored Links
Advertisement
 
post #4 of 24 (permalink) Old 05-24-2019, 11:43 PM
Sr. Member
 
Join Date: Aug 2011
Posts: 489
Yeah, google Reduced Voltage Control and a lot of interesting info pops up.

I, for one, was totally unaware of the lengths GM has gone to eke out every MPG. An added advantage to reducing the voltage is to not overcharge the battery.

Here is a link to an article titled Not Your Father's Charging System. It is very informative
https://www.searchautoparts.com/moto...ystem?page=0,0

Here is another. The interesting part here is that it looks like as you are driving (and monitoring the voltage) you can mash the throttle and the voltage should (fairly quickly)increase as the system enters charging mode.
http://ricksfreeautorepairadvice.com...stem-problems/

I don't really know, but my guess is that you don't really have a problem.
spook is offline  
post #5 of 24 (permalink) Old 05-25-2019, 07:17 AM
Sr. Member
 
rjayl's Avatar
 
Join Date: Oct 2017
Location: Michigan
Posts: 263
Garage
Quote:
I'm actually at 12.2, which may also explain why my battery light hasn't come on yet, but that still seems low for cruising down the interstate...
That sounds like normal operation. Here are the charging cycles per the manual:


2011 GMC Terrain 3.0L AWD
2008 Chevy Impala SS
rjayl is offline  
post #6 of 24 (permalink) Old 05-25-2019, 07:35 AM Thread Starter
Hero Member
 
Join Date: Jan 2015
Posts: 891
Thanks guys...so basically, in a nutshell, if I were having a problem, the computer is smarter than I am, and it would tell me by turning on my battery warning light. Maybe thatís why GM didnít include a volt meter in my car so as not to alarm folks like me who like to monitor what the car is actually doing.

I only spent $45 on a used alternator, and Iím ok with spending that for a little peace of mind that Iíve got a spare. Iíll keep an eye on it of course, but it seems this may even be normal.
BandDirector is offline  
post #7 of 24 (permalink) Old 05-25-2019, 12:26 PM
Full Member
 
Join Date: Nov 2018
Posts: 132
Quote:
Originally Posted by BandDirector View Post
Thanks guys...so basically, in a nutshell, if I were having a problem, the computer is smarter than I am, and it would tell me by turning on my battery warning light. Maybe thatís why GM didnít include a volt meter in my car so as not to alarm folks like me who like to monitor what the car is actually doing.

I only spent $45 on a used alternator, and Iím ok with spending that for a little peace of mind that Iíve got a spare. Iíll keep an eye on it of course, but it seems this may even be normal.
Your voltage readings are normal for a fully charged battery. The charging system has a current/temp sensor on the negative side of the battery cables. The Body Control Module monitors open voltage of the battery, as well as how much current is added and subtracted from the battery. In Economy Mode, it will settle down to 12.5 - 12.6v. You can force it into charge mode by turning your lights on, or wipers on, or AC on, or rear defrost. My manual says if the fan is set to high with no AC, it should enter charge mode but have not found that to be true. It will drop to 12.3v instead of boosting the voltage. So far it does not seem to drain the battery. I check in the morning while the car is still locked, and battery is 12.65 - 12.7v.

You can test the internal regulator by disconnecting ECM connector on the altenator. It will set a DTC, and regulate voltage at a constant 13.8v.

I purchased an online service manual through Mitchell!, for about $30 a year, it really helps explain things. The charging system is one example.
sydnesb is offline  
post #8 of 24 (permalink) Old 05-26-2019, 12:05 PM
Theta Freak
 
rednox301's Avatar
 
Join Date: Nov 2014
Posts: 1,671
Quote:
Originally Posted by BandDirector View Post

I only spent $45 on a used alternator, and Iím ok with spending that for a little peace of mind that Iíve got a spare. Iíll keep an eye on it of course, but it seems this may even be normal.
I agree that your alt is probably working as intended.
Always nice to have an extra starter and alt on the shelf if you need it.

I would take this one step further and have your alt tested at your local rebuild shop.
The one I use will spin it up to test it, and give you a print out for free.
That way you can box it up for later with confidence.

2014 Equinox LTZ FWD 3.6L. V-6 (LFX)
GM6T70 Transmission-Gen II(M7W)
Crystal Red Tintcoat-Brownstone Leather-(FE2) Suspension-18" Wheels
Build Date: Nov. 04, 2013-Delivery Date: Nov. 25, 2013
rednox301 is offline  
post #9 of 24 (permalink) Old 05-26-2019, 01:39 PM
Theta Guru
 
Join Date: Feb 2011
Posts: 3,135
Quote:
Originally Posted by rednox301 View Post
I agree that your alt is probably working as intended.
Always nice to have an extra starter and alt on the shelf if you need it.

I would take this one step further and have your alt tested at your local rebuild shop.
The one I use will spin it up to test it, and give you a print out for free.
That way you can box it up for later with confidence.
Check out this guy's "home test" !


2011 Equinox 1LT (new Jan 2011): Summit White / 3.0 L V6 / FWD / Pioneer Stereo / 18" Wheels / 131.6k miles [14-JUN-2019]

2002 Impala 1LT (new Jun 2002): Summit White / 3.4 L V6 / FWD / Cassette-CD Combo /222.5k miles [13-JUN-2019]
Colt Hero is offline  
post #10 of 24 (permalink) Old 05-26-2019, 04:19 PM Thread Starter
Hero Member
 
Join Date: Jan 2015
Posts: 891
Quote:
Originally Posted by Colt Hero View Post
Check out this guy's "home test" !

https://www.youtube.com/watch?v=RQxkAEirtV0
Quote:
Originally Posted by rednox301 View Post
I agree that your alt is probably working as intended.
Always nice to have an extra starter and alt on the shelf if you need it.

I would take this one step further and have your alt tested at your local rebuild shop.
The one I use will spin it up to test it, and give you a print out for free.
That way you can box it up for later with confidence.

That's the plan, but I'll take it one step further and probably store the spare alternator in the spare tire well...I learned that trick the hard way. I had a spare on the shelf for my last car, but it went out on a trip to Savannah and ended up paying a shop to install a new one since it died completely 3 hours from the house


...and Colt Hero, I have no doubt that guy won his school's science fair in the 5th grade!

-2015 Chevrolet Equinox SS 301HP V6
-1998 Chevrolet Camaro Z28 400.1 RWHP 6 Speed
BandDirector is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TerrainForum.net: GMC Terrain Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome