Dometic CoolAir RTX1000/RTX2000 12V Power Wiring Kit, 26 ft

The Dometic CoolAir RTX1000 and RTX2000 are 12-volt rooftop parking coolers built to keep a truck cab, camper van, or RV comfortable without idling the engine. This is the power wiring kit Dometic specifies to connect one of those units to your house battery. It isn't the air conditioner and it isn't the roof mounting hardware. It's the harness that carries current from the battery up to the unit on the roof, and it's the piece a lot of installers forget to order until the AC is already sitting on the bench.

Inside you get a 26-foot, or 8 meter, power cable run in heavy 4 AWG wire, an Anderson-style connector that mates to the plug on the RTX unit, ring terminals for the battery end, and the fuse that protects the circuit. The 4 AWG gauge isn't overkill. An RTX2000 pulls real amperage on startup and on a hot afternoon, and thin wire over a long run drops voltage fast. Four-gauge copper keeps the unit seeing the voltage it needs so the compressor cycles the way it should.

The 26-foot length is there for a reason. On most builds the AC sits on the roof while the battery lives under a bench, in a rear garage, or up near the cab, so the cable has to travel most of the length of the vehicle and still leave slack for a clean, strain-free connection. Cutting a shorter aftermarket cable to save a few dollars is where a lot of installs go wrong. Give yourself the full run, route it away from sharp edges and heat, and you won't be chasing voltage-drop problems later.

The Anderson-style connector is the part that makes this a real kit rather than a spool of wire. It gives you a keyed, high-current disconnect, so you can pull the roof unit for service or winter storage without cutting anything. The included 80-amp fuse sits on the positive leg close to the battery, which is exactly where it belongs. If the harness ever shorts against the frame or a screw finds the cable during a later project, the fuse opens before the wire becomes a problem.

If you're installing an RTX1000 or RTX2000 for the first time, you need this kit. Dometic builds the roof unit and the wiring as a matched system, and the connector on the AC is made to meet this harness. Van builders wiring a fresh electrical system, RV owners adding rooftop cooling, and fleet shops outfitting sleeper cabs all reach for the same part number. Pair it with a 12-volt battery bank sized for air conditioning and you've got the backbone of a system that runs without the engine.

A couple of things to know before you order. This is the electrical connection only, so you'll still need Dometic's mounting and installation hardware to seal the unit to the roof opening. And while the supplied 26 feet covers the factory-specified run, if your battery is mounted unusually far from the roof, plan your routing so the cable reaches without splicing. For the vast majority of truck, van, and RV installs, this kit drops in and does exactly what the RTX manual asks of it.

One habit that pays off: make sure the Anderson-style connector is fully seated and latched before you power up, and give the battery terminals a proper crimp with a real tool. High-current DC connections don't tolerate a loose fit. A connector that's only half-mated, or a terminal squeezed with pliers, will heat up over a season of use. Ten minutes of care at install time is what separates a harness that lasts the life of the AC from one you're redoing next summer.