A/C pump engaging with cabin heat on?

[BadaBingM3]

So after I’ve dropped a new engine in my 99 explorer sport (4.0 OHV), new A/C lines and seals, etc. A/C works great. But now that it’s a lot cooler out, as I use the cabin heater (all settings), I’ve noticed the A/C clutch kicks on and off while Ive got the heater on. Never noticed this before with the old engine and not sure how that could be related but the rpm increases with clutch engagement while using the cabin heat settings is more pronounced. At idle, I’ve noticed it kicks on and off a lot. Say about every 5 seconds it engages for about a second then disengages over and over. Is this normal?

Thanks!

 

[C420sailor]

The AC is commanded on for dehumidification in the following positions:

MAX A/C
A/C
Panel and floor
Defrost and floor
Defrost

Mixer position (hot/cold) doesn’t matter.

If you don’t want the AC to kick on, select panel only or floor only.

Cycling every five seconds sounds excessive. Hook up a set of gauges and check your pressures. Mine was cycling like that when it was low on refrigerant.