My truck sits for 3+ months at a time frequently. Fuel tank is full and battery tender hooked to truck. Just connect the tender to one battery or the other. The crossover cable will keep both batteries charged.
Do not start it and let it idle frequently. It will never reach operating temperature. Not saying you can't start it to move it or unhitch or whatever, but don't make a habit of idling for 15-30 minutes weekly/monthly/whatever then shutting it down in an effort to 'maintain' the truck.
Mine has been sitting since Thanksgiving. I will use it in 2 weeks to go pick up a trailer 300mi away and bring back to the house. I will just get it out from under the shed, check the tire pressure, load my junk and leave. When I return I will fill with fuel and pull back in to shed, connect tender and walk away.
2005 2500 Cummins/48RE/3.73, QCLB, 4wd, BigHorn, Edge Juice w/ CTS + Turbo Timer,Transgo Shift Kit ISSPro Oil and LP pressure gauges, GDP 20/2 filters, Custom Diesel Steering Box Brace
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