Installed new rm2620 fridge no power to 12v

Test light or volt meter reading will tell you use ur tools for it to help you

Is this a new fridge or the one that came in a trailer? If it is installed it should be wired, have you checked fuses? If it's not installed there should be instructions with the frig or check the Dometic web site.

4 batteries in parallel equal 480 a/h so if you pull 10 amps as an example it would last 48 hours. To measure current the amp meter would have to be in series with the total output of the four batteries. If you go between the batteries current is divided due to being in parallel Divide the total a/h by the current being drawn to work out the time frame .

If the RV is level and the rear coils of the cooling unit are warm, then you will require a replacement cooling unit. Changing the cooling unit is something that can be done by the end user such as yourself. Check out Arcticold Cooling Units.here ArctiCold Refrigeration We keep it cold or give them a call toll free 1-888-782-6665
By replacing the cooling unit with an aftermarket one, it will save you you money (vs buying a new fridge) and increase the performance and durability of your fridge. Arcticold cooling units can be purchased on ebay Dometic RM2611 Brand New Manufactured Cooling Units LIFETIME WARRANTY... The RM 2611 cooling unit is the same as the RM2620

If you have a volt meter, switch the volt meter to 12v, locate the motor in the back wheels and if you can see where the wires connect to the motor touch the terminals of the volt meter to the two connections and turn on the power wheels press the power pedal and see if you get a reading of 12v. If you can't touch the wire or where the wire connects try disconnecting the wires and testing it that way. If you have 12v at the motor then it seems the motor is shot. There should be two motors one fit each wheel and its unlikely that they would both go. If you don't have power at the motor try following the wires to the pedal and also the forward reverse switch. Test these in a similar fashion. Hope that helps

On the back side of the unit there will be a small thermostat switch mounted on the heat column. It will be round with two wires attached to it. In the center is a reset button. If this button does not restore power then the next step is to replace the wire coming from 12v supply to the thremostat switch. The wire will be red and will have a black sleeve on it. Under the sleeve is a safety diode (to prevent overheating and fire), it will be held in place with three bendable metal fingers. If the diode is bad it will not allow 12v power to pass through to the circuit board. Even though the refrigerator is running on 110v power the circuit board still requires 12v power to operate. The diode is a part of a FREE recall kit offered by Dometic so your local RV repair center should be able to help you out.

The yellow wire does not get used unless you have a power antenna to hook it to. The red wire is suppose to be hooked to the wire that was used as power for the stock stereo, so it turns on and off with the key. If you have it hooked to constant power, it has power coming to it even when it's turned off. That and the fact that you may need a better ground is most likely the reason you're getting the moise even when turned off. You may also want to check your speaker connections.

did you use an installation harness? you should have the following when you test-
red wire-12v only with key on
yellow wire-12v at all times
reverse your test light to check the ground wire should be 12v with test light hooked to pos