engine gets plenty hot, about 200 deg. Blower motor works well. The heater hoses are very hot all the way up to the firewall. I assume this is the heater core? Is there anyway to flush this thing? I don't want to pull the dash, I did a few years ago, when the evaporator started to leak. Is there any flush chemicals, and compressed air would uncork this thing, if it is actually plugged up. I disconnected the A/C unit, to make sure it wasn't fighting each other.

Could be heater core or could be blend door. There have been a number of post recently about this. You might try a search to find them. I'd use a waterhose instead of compressed air. You won't risk blowing the core apart that way.

https://board.moparts.org/ubbthreads/show...rue#Post4854154 I have reveresed the hoses and flogged the throttle and unplugged one, I have also used compressed air regulated down to remove abstructions

Make sure the temp control knob is not broken,

I just switched the hoses on my 91 dak a couple weeks ago and it helped a ton.

I had problems with my minivan just like that. It turned out to be a small leak in the rad. tank and not enough water for the heater to work. Gauge was not hot either. Filled it up and heater worked. Changing the rad was not too bad but better than messing with the heater core for sure. Check to be sure.