2008 Ford F-350 6.4 diesel rough idle in gear at a stop light only does it when the ac is on?

2008 Ford F-350 6.4 diesel rough idle in gear at a stop light only does it when the ac is on?

Idle is usually raised aoutomatically wehen AC on. This isn't working by the soound of it.

That's nice. Did you want to ask a question while you're here?

Lots of vehicles will have a lower idle when at a stop and the AC is on… If you are concerned, then look in the owners manual

See a (diesel) mechanic with a scanner.