older a/c smelly issue

My truck does that sometimes.
Condensation grows mold and such.
Try leaving just fan on for a few minutes with A/C off.
Cleaning coils will probably clear it for awhile but will come back.

I'll try that, thx

x-2 on coil cleaning. This stuff worked well for me
Lowes

Recently cleaned the cooling coil on roof. Have to take it apart to the point you can see inside camper from roof. Used a foaming cleaner and rinse with water from spray bottle. Used towels to keep water from entering camper. Smells lemony fresh now!

Are you sure the condensation lines are flowing? If not that is the cause.