Wiring Diagram and Instructions for the Deka Battery Isolator

Updated 03/21/2024 | Published 03/15/2024

Question:

I installed a 120 into my 2001 silverado. I apparently need the 4th post and have tried several options with the plug provided. I must be doing something wrong. the batteries dont charge and my battery lite on the dash comes on. I have battery to one, side battery on the other, alternator in the middle nothing I tried on the little post works. Im out of ideas.

asked by: Dan

Expert Reply:

Hey Dan, so it looks like to wire up the Deka Battery Isolator # DW08771 you'd need to start by connecting terminal 1 to the positive battery terminal of the main battery. The original wire from the alternator to the main battery would be then be removed from the battery, and installed on terminal 1. Terminal E would need to be connected to the an ignition circuit that's hot only when the key is switched on via a 6 amp breaker. Terminal A would connect to the battery lead on the alternator and finally terminal 2 would connect to the positive terminal of the auxiliary battery.

expert reply by: Bryce D

DW08771 Diagram
(click to enlarge)

Dan

3/18/2024

forgive me but we have a "terminology" problem here. I have no idea what you mean by terminal E Then you use terminal 1 for the battery and terminal a to the alternator and terminal 2 to the positive. You gotta make up your mind man lol let me get this straight I need battery to left, battery to right, alt to middle and the little post goes where? the instructions say to change the plug wire to the alt and one side or the other should be what you say right? I tried both so I'm still confused. What goes on the little post??

Bryce D.

3/19/2024

@Dan That sounds correct to me, and It looks like the little post, "E" presumably from the diagram, would need to have a new wire ran to 12V ignition power source.

Dan

3/18/2024

ok I found that one of the wires to the alternator plug lites up with the key. I spliced into that before the plug connector and verified it is hot only when the key is on. Put that on the little post. Disconnected the extra wire added to the plug as per the instructions as well there is no power to either 1 or 4 on the 4 pin alternator plug. plugged the plug back in and I STILL get a battery lite on the dash. both batteries are fully charged with my charger.

Bryce D.

3/19/2024

@Dan That's weird, Dan. Let me reach out to Deka and see if they have anything on this.

Dan

3/20/2024

@BryceD thanks so much. there must be a way

Dan

3/21/2024

@BryceD I think I got it! I got a fusable link and added a hot wire and gave it one of it's very own. The light went out and it seems to be charging. Thanks for all your help. I think the problem was with the instructions I read. My alternator just wanted something different. Thanks again. You guys are the BEST!