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Installing Battery Isolator in 2007 Silverado 2500HD

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Hi all, I'm planning on installing a smart battery isolator and upgrade the trailer battery charging line in my 2007.5 LMM Silverado 2500HD, similar to  this.  The 12V power line was hooked up to the fuse box when I bought my first rig, but by default my RV batteries will drain the truck batteries if I don't disconnect the 7 Pin.  I figured I would disconnect the existing 12V power line, connect the isolator to the post, and run the heavier gauge wire all the way to the truck's 7 pin connector from the isolator.  However, in thinking further about this, would the battery isolator also cut off power to the trailer brakes?  Or do the trailer brakes not utilize the 12V aux power line?   Thanks! 

Edited by dartmouth01
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It appears ??????? the isolator is designed to be used  ONLY  for remote charge control FROM the tow vehicle back TO the trailer battery and connects the two or disconnects them based on the truck battery voltage.........That should NOT interfere with the electric brake function as it (should at least and if I wired it) gets its power DIRECT from the truck battery independent of the isolators TO TRAILER line regardless if the truck and trailer batteries are tied via the isolator. Just insure the 12 volt feed wire to the electric brake controller voltage input is fed direct off the truck battery NOT dependent on the isolator. IE NOT fed via the TO TRAILER side of the isolator. DO NOT wire the brake controllers voltage input line off the isolators "trailer battery" circuit, get it ?????

The trailer brakes use a separate pin in the 7 pole connector (2 Blue Brake, see picture) its NOT the same as the auxiliary voltage feed pin (4 Black see picture) that can be used to provide some charge to the trailer battery 

The charge line (truck to trailer) is susceptible to line voltage drop and the integrity and resistance of the 7 pin plug and receptacle. Line voltage drop is reduced if you run bigger wire from the isolator back to the 7 pin receptacle and that connection IS NOT any high current rated device. Sure it can provide some degree of charging from the truck to trailer battery even with smaller wire and less then perfect connections, but I consider it as maintenance and trickle charge NOT any super high capacity high current let alone SMART multi stage charging for deep cycle trailer batteries. IT IS POSSIBLE to better protect the trucks alternator and provide a better more regulated multi stage quality charge FROM the truck TO the trailer using a DC to DC Charger. Renogy and others make them in 20 and 40 amp models  with settings for Lead Acid or even Lithium trailer batteries.

 Bigger wire is better to reduce line voltage drop from truck to trailer and I like the idea of the isolator being voltage dependent

John T


John T


Edited by oldjohnt
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