I had a mechanic replace a leaky Heater core in my Honda.
After his repair, when I start the AC and fan, I get cold air on the right side and hot air from left side and middle vents. Mechanic couldn't diagnose the problem.

Thanks in advance for help,

Beagle
Honda accord 1996, 4cyl; LX

 

Most likely explanation is the heater door that directs the air either over the heater core or to bypass the heater core is not working or jammed.

If the vent selection switches work OK to direct air to upper /lower vents, then heater door problem is likely.

The heater door is positioned by the "heat control ****" on the heater control panel. Turning to right should open the door to deliver heated air, and turning to the left (cold) should allow cold air from evaporator cooling to be delivered.

The heater door is very close to the heater core that was replaced.

Suspect your mechanic is playing dumb and hoping you'll go away as he should know this problem is related to heater core replacement.

good luck

 

How about low charge of AC refrigerant? I think that can cause uneven cooling across the face of the evaporator.

 

Jim's point is a good one. I have read of uneven cool air distribution when charge is low.

Was the AC system discharged to perform the heater core work? Was it working good before the heater core work?

good luck

 

Mechanic said that he didn't have to discharge refrigerant.
I have checked the refrigerant level after the work; it was good.

I passed on both of your suggestions to my mechanic. The problem turned out to be a faulty heater core door assembly. Some of its doors weren't closing properly. Now he has replaced the assembly and every thing works.

I knew, this mechanic might be lacking experience; but I wanted to help him by giving some work.

I really appreciate valuable inputs from TexasHonda and JimBlake.

Beagle

 

Curious... how did you check refrigerant level?

Thanks for coming back & letting us know how it turned out.

 

Mechanic checked high and low pressure lines.

Beagle

 

Good. I was just trying not to take anything for granted.