a/c blows hard on cold, but barely blows on hot

[Zone_4_Lanlord]

My a/c blow hard with them temp selector on cold, but when i switch to heat it barely blows. Whats the cause of this? If its on heat, the more i move it to cold, the harder it blows. The heat is hot it just barely coming out of the vents. All vacuum lines are fixed, everything else works. it blows hard on cold, but not on heat. Any advice would be greatly appreciated.

 

[69hurstolds]

You cannot access the door itself, just the cable connection for the blend door rod sticking through the firewall.

If the blend door was disconnected and blocking off the heater core flow, then you would have the same amount of flow on heat as you would on cold, and no hot air flow because the door didn't move. From what you describe, you have good flow on cold, but poor flow on hot. Meaning it seems highly likely the door is moving to close off the heater bypass (COLD) plenum when taken to HOT. Nothing else changes, so it should be moving the door only. Unless something is wacked out with your 9 port selector valve somehow, but that shouldn't move just playing with the hot/cold lever. Did you try this in every mode to see if flows changed from hot/cold? Or got redirected?

SOMETHING is blocking your flow through the heater core. If it's new, I'm assuming you cleaned all that crap out of there, so it must be something past the heater core then. The hot/cold lever has nothing to do with the vent actuator pods, so I can't see how that could change anything. Air is always routed to go somewhere. But it won't when it's blocked.

I'm out of ideas. Next?

 

[Zone_4_Lanlord]

I tried it in every mode, and i have a brand new heater core installed. Could it be my vacuum lines out of wack someway?

 

[GP403]

Can i access blend door without pulling dash?

Yes, pull the glove box out to get access to it.

 

[69hurstolds]

Yes, pull the glove box out to get access to it.

I believe you're thinking of the cable end. Pulling the glovebox only gets you access to the cable side of the rod. The rod goes through the foam seal in the firewall (usually foam is toast) and the other end connects to the door. If there's a problem with the cable, pivot, or rod clip on the pivot, glovebox hole access works. But if the problem is the door itself, you have to take the top off the HVAC housing under the hood.

Pivot lever in pic below. This is the only thing you can actually access through the glovebox hole. The rod just snaps into that little white clip. If that clip breaks...HARD TO FIND. I don't know if they're repro-ing those or not.

Cable hooks to the bottom of that pivot lever. The tip of the lever that holds the blend door in the pic below has broken off.

 

[GP403]

I believe you're thinking of the cable end. Pulling the glovebox only gets you access to the cable side of the rod. The rod goes through the foam seal in the firewall (usually foam is toast) and the other end connects to the door. If there's a problem with the cable, pivot, or rod clip on the pivot, glovebox hole access works. But if the problem is the door itself, you have to take the top off the HVAC housing under the hood.

Pivot lever in pic below. This is the only thing you can actually access through the glovebox hole. The rod just snaps into that little white clip. If that clip breaks...HARD TO FIND. I don't know if they're repro-ing those or not.

Cable hooks to the bottom of that pivot lever. The tip of the lever that holds the blend door in the pic below has broken off.

all true. in my case it was that lever that was broken off of its mounting pivot, so it was just a matter of pushing the busted part down into the box and putting a new one in. ("just" he says)... So no matter what you did it was stuck in one position... But yeah if the problem is internal to the box then you won't get to it from the glove box.

I'd start with the lever though.

 

[fleming442]

Sounds to me like it's switching between recirc and fresh

 

[Zone_4_Lanlord]

I dont understand how when it only shuts of air flow when i switch to heat but airflow is great when it on cold. I dont think anybody has the true answer.

 

[fleming442]

If they did, you would have it by now. Start troubleshooting; we can't fix it for you over the freaking internet!

 

[86CUT]

My a/c blow hard with them temp selector on cold, but when i switch to heat it barely blows. Whats the cause of this? If its on heat, the more i move it to cold, the harder it blows. The heat is hot it just barely coming out of the vents. All vacuum lines are fixed, everything else works. it blows hard on cold, but not on heat. Any advice would be greatly appreciated.

Did you resolve this issue?

 

[Zone_4_Lanlord]

Did you resolve this issue?

Im working on it right now