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Parts Needed to Allow Tow Vehicle Battery to Charge Trailer Battery While Driving


Two questions 1. I have an old VRBCS300W backup camera system. The power adapter for the monitor has died. Can you help me find a part number or replacement part? 2. I am wiring up a trailer and want to prevent battery drain from my truck when it is not running. Is there a way to do that? If so what pieces parts do I need? Thank you!


Expert Reply:

I can't help you with the power adapter for your older backup camera since we never carried that part, but I can help you make it so the tow vehicle you have won't continue to charge a trailer's battery when the vehicle is turned off to prevent battery drain.

You can use part # TR118665 from TowReady. This isolation solenoid provides for an ignition controlled flow of current from your tow vehicle battery to the trailer battery. The solenoid will allow the 12V feed to remain active only when the vehicle is running; when the truck is turned off the 12V feed will also shut off. This will prevent battery drain in the truck but still allow charging of the trailer battery when the truck is running. The photo provided shows how this device connects. You will need ring terminals to connect, such as # DW05705-1.

You will need to use an ignition-controlled circuit in your truck to activate the solenoid. The radio circuit is often used for such purposes. You will need a fuse tap to access the switching function on this circuit; you can use part # F2526 from Firestone. This plugs into the fuse socket for your radio and connects to the center post on the solenoid. 12V power from the tow vehicle battery connects to the left terminal and the power output from the right terminal connects to the hot side of your 2-wire charging line.

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expert reply by:
Jameson C

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