Extremely loud air conditioner fan noise on Kountry Star

[KTYSTR]

I assume all owners with the gas 8.1L engine on a Workhorse chassis are used to hearing the two cooling fans come on at various times and make some, or very little and then decreasing noise as they cycle from on to off.
I have an additional, very loud noise that I only hear when driving in slow moving traffic with the air conditioner running.
The fan(s) comes on but is screamingly loud (very loud and high pitched, high speed sound). When I stop at a stop light or in stop and go traffic, the fans sound like they will rip themselves off the coach, and then will suddenly stop and all is quiet. As I move again, the cycle will repeat.
I can instantly stop the noise by cycling the air conditioner to off.
Is there another set of fans used by the air conditioner I cannot see? Or is there only the two fans that run to cool the transmission, engine coolant and air conditioning that are making the horribly loud sound when running my air conditioning in traffic?
Anybody else had this annoying and very lound fan noise with the air on and in stop and go traffic? By the way, the excessivlely lound fan noise is never heard while driving at highway speeds...only in stop and go traffic resulting in frequent stops. I worry about something starting to self-destruct. Any info appreciated.

[KTYSTR]

I assume all owners with the gas 8.1L engine on a Workhorse chassis are used to hearing the two cooling fans come on at various times and make some, or very little and then decreasing noise as they cycle from on to off.
I have an additional, very loud noise that I only hear when driving in slow moving traffic with the air conditioner running.
The fan(s) comes on but is screamingly loud (very loud and high pitched, high speed sound). When I stop at a stop light or in stop and go traffic, the fans sound like they will rip themselves off the coach, and then will suddenly stop and all is quiet. As I move again, the cycle will repeat.
I can instantly stop the noise by cycling the air conditioner to off.
Is there another set of fans used by the air conditioner I cannot see? Or is there only the two fans that run to cool the transmission, engine coolant and air conditioning that are making the horribly loud sound when running my air conditioning in traffic?
Anybody else had this annoying and very lound fan noise with the air on and in stop and go traffic? By the way, the excessivlely lound fan noise is never heard while driving at highway speeds...only in stop and go traffic resulting in frequent stops. I worry about something starting to self-destruct. Any info appreciated.

["007"]

Have you tried your "heater" which uses the same fan for cooling to see if its the same sound coming from the Evans air and heater unit.
Sounds like it might be a bearing going some place.