I'm trying to wire a round Honeywell thermostat to an Electric A/C Heat pump. No Idea wha twires go where. It is a 4 wire system. Wire colors are Brown, Orange, Blue, White. Can Anyone help me?

There is a standard color code for thermostat wirng, and your colors are certainly not it. All I can suggest is to trace all the wiring and determine where each wire goes and get back with more detail.

Standard color code at a stat is:
Red feed to stat
White return to heat system
Yellow retrun to AC system
Green to fan relay

Sorry not to be more help, your colors can be for any of the systems I listed..

I agree with tkrussel... much more information needed. And tkrussel how in the world do people come up with all of these odd combinations of how their wiring is done. I have been doing this for over forty years and I have never wired a system with these odd ball colors. And another things,, how are we suppose to give any help from this kind of information when it would be hard enough looking at the wiring diagram...