Hello all, I'm not 100% sure what this issue could be.

I have a 1989 Fleetwood 4500 Commercial (hearse) that has a hvac issue.
When I turn the heating on nothing happens and when switching it to AC nothing happens, but when I change temperature I can hear what sounds like the actuator open and close and when changing the areas such as front vents to floor vents I can hear it switch but its not blowing anything out.

I have read over a few places where other people had similar issues and some people say it's the blower motor others say its the blower control module/resistor, but no one followed up with what they did to repair it. I have also read that someone said it's the relay only then to read that this model doesn't have a relay.

I've checked over fuses and they are good..
can anyone advise where I should start to look to start the process of elimination.

So I changed the relay just to be sure and still the same thing...nothing happening.

Thanks in advance.