Lets just hope that HC2400 hasn't been murdered.
Like i said on the phone.
Now that you may have brought it back up to slight normal rest still doesn't mean it's good.
There are still a few things that concern me.
1. When your vehicle is running you still are getting a pretty good gap in voltage from the front reading and the rear.
2. Make sure you check all the setscrew connections on all your fuse blocks between the front and rear battery. Fuses DO add resistance on the run.
3. You need to double check your ground points for both the rear location, amp, and front location sense you stated you upgraded the front ground.
4. IMO and i will live by this and always have. You need to add a Run of 1/0 from the "Positive" on the Alternator to the "Positive" on your front battery. MAKE SURE THE CONNECTION IS TIGHT and that the ring terminal DOES NOT and WILL NOT come into contact with the Alternator Casing. AT ALL PERIOD!!
You may want to fuse this lead if you are not comfortable running straight wire. Fuse it as close to the alternator as possible if you are able to.
5. Add a run of 1/0 from the Alternator Bracket that is in direct contact with the casing to the "NEG" Post on your front battery. Make sure its TIGHT, SECURE and there is no need to FUSE this Run.
Finally I would suggest you run a NEG run of 1/0 to the back battery from the NEG Post on your front battery. I say this because from the Voltage differences i am see when your vehicle is running. Secondly its more of a direct pathway for the parallel. connection of your front and back batteries.
