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Pknappe · 10-25-2020, 01:52 PM

Traveling to Moab and the unit was working fine on the generator. Hooked up to 30 amp and 50 amp service and nothing on the display. Also not working now on the generator. I have 120 v to microwave and refer, but AC does not work. I checked the 3 amp fuse and it does not seem like there is power to the fuse. Rest of 12 v fuse panel seems to have power. This is based on pulling the fuse out and the little red led light comes on. I have. 2006 Coachman Cross Country.

jacwjames · 10-25-2020, 03:50 PM

On my EMS760 I have to have the washer/dryer breaker on for the display to work, not sure if impacts the operation of the EMS though.

You can try to do a complete reset by shutting off all AC & DC power, pulling the fuse, wait ~10 minutes.

If that doesn't work you may have a bigger problem. Contact M&M Electronics in Ohio https://www.mmrvelectronics.com/ They can walk you through more trouble shooting. I had to do this and found my board was bad and had to upgrade/replace with a new board and load monitor. They overnighted me the parts to the destination I was traveling to, good group to work with & support.

If you are electrically inclined you may be able to bypass the EMS board by simply taking the 2 wires out of each realy and wiring nutting them together. I did this to get one AC unit working until I got my new board. You can bypass all the relays but then will have to control power to below 30 amp if plugged into that size hookup. Take pictures, make a wiring diagram, and put labels on the wires before you start.

Pknappe · 10-26-2020, 07:30 AM

All the breakers are on. I did try the reset and no luck. What is strange is there is no power on the 3 amp fuse. I will take apart today and see what I see. Thanks jacwjames for the input. I think I’ll be calling them for help. Luckily it is 26 degrees outside so I don’t need AC

jacwjames · 10-26-2020, 04:52 PM

Do you have the manual for this, https://www.intellitec.com/wp-conten...-00894-600.pdf

it does have some trouble shooting steps. 12 volt power for the board comes in from one of the two wiring harnesses, it shows it in the manual.

Do you have the a wiring diagram for your rig, it may show where the 12 volt power comes from.

On my coach it shows there is a 15 amp fuse in the house fuse panel that provides power to the EMS system & tank monitors, not sure how it is labeled. Did you check all the 12 volt fuses in your house circuits?? Yours will be different.

My guess is that if there is no 12 volt power the system won't work.

You can completely bypass the system or portions of it until you figure it out.