I did it! I FINALLY did it!! Dual batteries
Posted: Thu Dec 05, 2024 7:11 pm
Coop
Coop
BAWC Forums
Let the shens continue...
https://bawcforums.org/phpbb/
I did it! I FINALLY did it!! Dual batteries
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Coop
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Thu Dec 05, 2024 7:25 pm
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Thu Dec 05, 2024 7:31 pm
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Thu Dec 05, 2024 11:53 pm
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 12:54 am
Exactly!!!!
Coop
Coop
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 1:05 am
Study hard. 
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 1:43 am
So is it like I read? Charges both but only starts and uses one?
Coop
Coop
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 2:11 am
Kinda looks that way. But only when the aux battery relay is closed. I think it's controlled by the PCM. I'll get the power distribution schematics next.
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 3:54 am
I’m guessing it only uses one unless lower voltage or high current draw is detected and it starts using both. Also looks like the second battery can be used to start it as well.
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:00 am
This is from the service manual.
Check your owners manual. I wonder if you can jump it off the secondary battery if the primary is dead.The auxiliary battery relay coil is energized with the engine running through the fuse block and wiring, thus closing the relay contacts which allow the battery to be charged from the vehicle's generator via the battery junction block. The auxiliary battery relay is permanently grounded so any time the ignition switch is in the run position the relay will be energized.
The auxiliary battery is only used for accessories and is not part of the vehicle starting system. However if the primary battery fails and in need of an jump start, follow the service information for Jump Starting In Case Of Emergency using appropriate battery jumper cables.
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:14 am
No can do….no manual to be found.
Coop
Coop
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:24 am
https://www.dezosmanuals.com/wp-content ... Sierra.pdf
There's nothing in there specific to jump starting a dual battery setup.
There's nothing in there specific to jump starting a dual battery setup.
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:31 am
Well that gave it away!
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:36 am
Oops
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:38 am
Bet that manual says something about that fuse link in there to connect the second battery to the starter.
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:42 am
It actually doesn’t say what to do in the manual you posted Jeff
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 5:16 am
Haha. It’s all good. It’s not at the house to post pics. It’s a long story. I will make its own thread when I get it here. But here is a pic from the Facebook ad. I can’t believe how clean it is under, I would put it up against new cars at the dealer. It’s impressively rust free.
8.1 Allison 4:10 gears……and factory dual battery set up on a gas engine!!! Pretty rare option, not sought after, just not needed as all I found is that the second batter goes to the trailer only. I know jeff will be able to tell me though.
Crew cab king bed. It’s 14” longer than the avalanche. I am worried about the driveway.
Coop
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 6:20 am
Crew cab 8ft bed!? Is one end in NC while the other is in AR?
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 10:54 am
It’s only 14” longer than the avalanche.
Coop
Coop
Re: I did it! I FINALLY did it!! Dual batteries
Posted: Fri Dec 06, 2024 4:39 pm
2001 Sierra brochure. Some nice diagrams and frame pictures in there.
https://www.auto-brochures.com/makes/GM ... a_2001.pdf
Page 3 pretty much sums up Coop. "You can never have too much truck"
Speaking of...
https://www.auto-brochures.com/makes/GM ... a_2001.pdf
Page 3 pretty much sums up Coop. "You can never have too much truck"
Speaking of...
That's the short bed. Crew cab long bed is 256". 34" (nearly 3 feet) longer than the Avalanche. It's on page 47 of that brochure.Coop wrote:It’s only 14” longer than the avalanche.