short in wiring

[trm3650]

hello, newbie here. say i am working on my jayco, i keep blowing a 15 amp fuse at the convertor, it goes to the A/C unit and the furnace, and of course the wall thermostat.as soon as i put in a new fuse it pops real fast, sometimes it will work for a bit when we put a fuse in it. would anyone have any ideas on where to start

[rockylarson]

My converter only charges my batteries. From there the 12 volts are sent wherever it is needed. The fuses on my converter protect it from miswiring and/or reverse polarity from the incoming 120.volt system.
Good Luck and stay safe.

[Old-Biscuit]

Hello trm3650 and Welcome!

Post Brand/Model of A/C Unit and Furnace and type of thermostat

15A is MAIN DC for controls
Typically that FUSE would feed DC directly to furnace and it then gets triggered by DC back from thermostat to start furnace FAN
Some designs have the DC going to a control module in A/C Unit

SO Bran/Models will be helpful


** I grew up in Casper
Went to East Jr High, Dean Morgan Jr High, Natrona County High and then Kelly Walsh where I graduated (Dad was oilfield and we moved to/from/back to Casper a LOT!)