5thGenRams Forums

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Charging issues

Jermo760

Member
Joined
Jul 30, 2022
Messages
7
Reaction score
0
I have a 2021 1500 with the pentastar 3.6 v6 and I have 73k on my truck. I do drive alot for work.i have already had to replace my battery and alternator/generator which has me concerned. The new alternator is doing the exact same thing and when driving at interstate speeds I'm only at 13.1 to 13.3 volts on my gauge cluster. I disconnected electrical components that I had hooked up Ie my light bar and subwoofer. It has not brought the voltage up at all. In fact it keeps dropping under driving load at any speed. I do not understand what the problem is. I have had subs and external lights on all my vehicles and NEVER have had this issue. I am also a 12v telematics professional installer. These issues are seriously making me consider going away from this RAM 1500 all together. Can anybody help me out? 13.3 volts driving on the interstate doesn't seem correct at all. I should be at at least 14
 

Rick3478

Ram Guru
Joined
Mar 3, 2022
Messages
1,409
Reaction score
1,711
Location
NW OH
This isn't your daddy's old float charge truck. These have a sensing element attached to the battery and the system monitors voltage and current in and out of the battery and controls charging accordingly under software control.

Being a "telematics professional installer", you should already know that. But I didn't hear even a hint of it in your post and you only mention voltage, which is only part of the picture, so it makes me wonder...

This is, then, a guess based on little hard evidence:

If you hook extra stuff up to the wrong "ground" point, you may be draining current from the battery that the system doesn't "see". And if you keep doing it, you will eventually have a dead battery that the system thinks is fully charged, and it will not try to add more charge.
You may think the battery has died, or the alternator, but it may be your faulty add-on wiring causing the problem.
 

Jermo760

Member
Joined
Jul 30, 2022
Messages
7
Reaction score
0
This isn't your daddy's old float charge truck. These have a sensing element attached to the battery and the system monitors voltage and current in and out of the battery and controls charging accordingly under software control.

Being a "telematics professional installer", you should already know that. But I didn't hear even a hint of it in your post and you only mention voltage, which is only part of the picture, so it makes me wonder...

This is, then, a guess based on little hard evidence:

If you hook extra stuff up to the wrong "ground" point, you may be draining current from the battery that the system doesn't "see". And if you keep doing it, you will eventually have a dead battery that the system thinks is fully charged, and it will not try to add more charge.
You may think the battery has died, or the alternator, but it may be your faulty add-on wiring causing the problem.
My wiring isn't faulty. Everything is installed correctly and proper. Ground has been tested before using as my ground point. And no being a telematics professional installer does not mean I should understand fully how the charging system works from a completely different source. If it was an classic alternator I wouldn't be posting on this forum. I didn't understand how the charging system worked but now I do and have a full understanding. It was a bad battery and I also had unfortunately a faulty PCM. All is good now.
 

Buzz62

New Member
Joined
Sep 7, 2021
Messages
1
Reaction score
0
As Rick3478 indicated the voltage and current draw is monitored by the ECM and it regulates the output current
for the MGU. It your battery is charged, and does not need current then it will limit the amount. (similar to an old fashion voltage regulator)

If your MGU always put out full current then your battery would be fried. Your system is working properly, just drive the truck and stop worrying about it. If there is a charging issue your battery would be going dead and the truck would set a code telling you there is an issue.
 

Users who are viewing this thread

Top