98' Chevy K2500 AC Issues

This one is fooling me around here is the details;

will blow air just fine out the windshield vent on hot or cold settings. Switch it to front dash will blow air on cold until I press the AC button. Seems to work with AC on hot. Will guess with my air not blowing to hard before my blower motor probably needs pulled and cleaned (just now found out about the famousness of this issue; I plan on pulling it sometime this week).

All known fuses and relays have been checked.

Any advice?

The blend door motor may be bad. If the fan blows good in defrost I would start looking at door motors.

Little update to this its stopped blowing out front vents on hot or cold unless the AC option is off. What would be the best way to start testing motors and do you have a diagram of were they are at?