What causes the furnace and the ac to come on at the same time

Wire touching either at the furnace or the t-stat

Reply I could not find any touching wires I looked for that too

Thought maybe the relay has gone bad

Could be the control board, or the t-stat. take the stat off the wall and jumper r to y and see if just the ac comes on or both

Is this a electric furnace?

This is a gas furnace and I disconnected the white wire from the control board and had friend turn unit back on and no heat just ac

OK, but you need to do this at the t-stat to see if the stat has gone bad.

I could do a continuity test on the wires though if I unhook from both control board and t-stat

Yes you can also do that as well

I will unhook from t-stat and see if that is not the problem do you think that the wires could have chaffed together

Maybe, or the subbase on the stat just went bad. Is it a digital one or a old mercery one?

I did have that problem once before on a unit I was working on at work where the wire had chaffed togetherI also have another a/c doing the same thing where both come on at the same time

Well it's a new mercury one but yeah same difference