GT350 Voltage

fastd

Member
Joined
Sep 5, 2017
Messages
21
Reaction score
0
Location
WAKE FOREST, NC
Vehicle(s)
Looking at a gt350
I have a 2017 GT350...noticing that the voltmeter often reads in the 12's. At a stop light was just 12.2; sometimes gets up to 14 but most often 12.7-13.1.

I called Ford service and the tech was trying to make it sound like this is OK but doesn't seem right...anyone have similar voltmeter readings?
Advertisement

 

Tomster

Beware of idiots
Joined
Feb 20, 2016
Messages
12,706
Reaction score
11,448
Location
FL
First Name
Tom
Vehicle(s)
'20 RR GT500R(CFTP), 18 OW GT350R Base, '17 AG GT350R Electronics Pack, '97 PG Cobra Convertible
Its fine. The system voltage is regulated to only charge the battery when it is low. Let it sit for a couple weeks and then see what the system voltage is then.....
 

iamevan

Active Member
Joined
Aug 27, 2017
Messages
37
Reaction score
6
Location
Sacramento, CA
Vehicle(s)
'17 GT350
I have a 2017 GT350...noticing that the voltmeter often reads in the 12's. At a stop light was just 12.2; sometimes gets up to 14 but most often 12.7-13.1.

I called Ford service and the tech was trying to make it sound like this is OK but doesn't seem right...anyone have similar voltmeter readings?
I’ve noticed the same thing. I don’t think it was acting this way before. Did you ever find out if it’s normal?
 

Demonic

Well-Known Member
Joined
Feb 21, 2017
Messages
987
Reaction score
995
Location
Boston
First Name
Austin
Vehicle(s)
GT350R
Admittedly I can’t speak specifically to the Shelby, but this is often just a function of how alternators are set up in general. As the alternator spins faster the output will be higher but is going through a voltage regulator that limits the voltage to say 14 V for example. When the battery is pretty much topped off, the voltage reading will effectively be reading the output of the alternator.
 

JAJ

Well-Known Member
Joined
Apr 9, 2016
Messages
1,573
Reaction score
1,220
Location
Vancouver BC
Vehicle(s)
2016 GT350 Track Pack
Your 2017 GT350 has a "smart" alternator and a "smart" battery. Normal voltage is 12.9 V and it scales up and down between 12.8 at 150F and 14.2 at 20F based on temperature.

This is from the alternator calibration for a 2016 GT350.
 

iamevan

Active Member
Joined
Aug 27, 2017
Messages
37
Reaction score
6
Location
Sacramento, CA
Vehicle(s)
'17 GT350
Your 2017 GT350 has a "smart" alternator and a "smart" battery. Normal voltage is 12.9 V and it scales up and down between 12.8 at 150F and 14.2 at 20F based on temperature.

This is from the alternator calibration for a 2016 GT350.
Where did you find this information? Temperature of the battery?

In the morning before a cold start my gauge cluster voltage reading sometimes reads as low as 11.3v. I use a multimeter on the battery and it reads 12.4-12.6v.
 
OP
OP

fastd

Member
Joined
Sep 5, 2017
Messages
21
Reaction score
0
Location
WAKE FOREST, NC
Vehicle(s)
Looking at a gt350
I’ve noticed the same thing. I don’t think it was acting this way before. Did you ever find out if it’s normal?
not sure if its normal but hasnt been an issue so im goong with it.
 

JAJ

Well-Known Member
Joined
Apr 9, 2016
Messages
1,573
Reaction score
1,220
Location
Vancouver BC
Vehicle(s)
2016 GT350 Track Pack
Where did you find this information? Temperature of the battery?

In the morning before a cold start my gauge cluster voltage reading sometimes reads as low as 11.3v. I use a multimeter on the battery and it reads 12.4-12.6v.
I have SCT's pro tuning software for the GT350 and it has the calibration tables for the alternator in it. The values I quoted were "nominal". The main purpose of this part of the alternator calibration is to adjust idle speed to compensate if the voltage gets too low. The table I looked at isn't clear on whether the temperature is the battery temperature or not.
 
Advertisement

 
MBGRAM-1
Advertisement
Top