I have an older mobile hm with a coleman/intertherm heat/a/c it's a 2 wire system, I have a brand new hunter 42999B thermostat which is either a 4 or 5 wire should this work, attatching black wire to RH and white wire to W ? Thanks

Wires to rh and w will/should make the furnace/heat work,, you need 2 more wires to make an ac work