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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: Cowman85 on February 19, 2009, 01:09:05 pm

Title: 86 c20 wiring up a dual battery
Post by: Cowman85 on February 19, 2009, 01:09:05 pm
the guy i bought the truck off of had removed the second battery for some reason. There is some kind of amp looking type box for "load sensing alternator" hook up (i hope i remembered right), everything was cut off of that and just one battery running on the front passengers side.
question is how do i hook up a second battery to this truck? the one i am using right now will be the lead, the secondary is older so i figured it better that way.
right now i think the only wire on the drivers side is the negetive battery terminal.
Title: Re: 86 c20 wiring up a dual battery
Post by: 808SS on February 19, 2009, 01:12:42 pm
Do you need the second battery?
Title: Re: 86 c20 wiring up a dual battery
Post by: Cowman85 on February 19, 2009, 01:26:17 pm
i am running a 450watt system right now and without that she could only crank over 4 times or so before the battery would start to slow, i am planning on installing more lights and accessories so it would be beneficial to the life of the first, not to mention the knowledge cant hurt.
i think i only need to know where to tie in a positive lead for the secondary battery, but i would like to know what the load sensing unit it that was hooked up before.
Title: Re: 86 c20 wiring up a dual battery
Post by: choptop on February 19, 2009, 03:33:14 pm
Ive got a 1000 watt system in the wifes 81 c20 and only one battery. Sounds like you need a newer, bigger battery. I have run a similar system in this truck with 8 KC Highlighters and never needed 2 batteries.
Title: Re: 86 c20 wiring up a dual battery
Post by: VileZambonie on February 19, 2009, 04:56:19 pm
If you are going to run dual batteries ideally they should both be in the same state of health. It's real simple to wire up. It needs to be in parallel. I'll post a pic in a minute
Title: Re: 86 c20 wiring up a dual battery
Post by: VileZambonie on February 19, 2009, 05:06:58 pm
(http://i6.photobucket.com/albums/y228/Sabaka454/dualbatteries.gif)
Title: Re: 86 c20 wiring up a dual battery
Post by: Cowman85 on February 19, 2009, 06:54:50 pm
thanks a million VileZambonie, thats exactly what i was looking for  :)
Title: Re: 86 c20 wiring up a dual battery
Post by: Combatmp29r on December 01, 2013, 09:20:51 pm
VileZambonie your a life saver. Ive been looking for the factory dual battery diagram for months. Even my my local dealership couldnt find it. I have a 85 K30 that came with dual batteries and has all the pieces still on the inner fenders but no wires. I will soon remedy that :)