[dugslug]

It gets kind of annoying up here in the Northwest that I need to use the A/C on a 70 degree day. If I roll down my window the air feels cool enough (especially in the evening), but using the vent feels like about 10 to 15 degree warmer air is coming out.

Any ideas of how this air is getting heated? Seems like a waste to have A/C on all the time.

Thanks for the replies.

 

[CPSS]

Not sure about your 2004, but on my 01, the hot coolant flowed thru the heater core all the time. The only thing keeping the air cooler was the "blend" door. I installed a ball valve in line with the heater hose to positively shut off the heater in the summer. Made a big difference. Now the vent position brings in cool outside air without adding any heat. /ubbthreads/images/graemlins/cool.gif

 

[Ford_Forgotton]

www.forgotton.net/diesel/heaterbypass/index.htm

click that. kill the hot water to your heater core.

 

[SmokeyWren]

[ QUOTE ]
... kill the hot water to your heater core.

[/ QUOTE ]

Been there. Done that. It helped the AC a lot. Click here. But the "fresh air" from the vents was still noticeably warmer than outside air. Caused by the hot ducts in the hot engine compartment, I guess.

I lost my AC back in east Texas on Memorial Day weekend. It was a long, hot 400-mile trip home. /ubbthreads/images/graemlins/frown.gif With outside air in the 90s and cruising with the windows partly down, we finally turned the HVAC controls to "OFF".

So in addition to the heater flow mod, if you want to use the "vent" mode of the HVAC you probably also need to add insulation to the HVAC ducts on the firewall.

 

[wingnut60]

In my '04, if I want to use the vent, I first have to turn the ac on til it cools the air coming out, then I can switch to vent and it runs cool outside air.?????? Too lazy to add the heater cutoff switch.

 

[dugslug]

I agree. The problem is with the vent, not the A/C for me since it stays below 100 degrees here. The vent air doesn't go through the box that has the hot air door does it? I guess maybe it does since you can heat up the vent air simply by turning up the heat.

SmokeyWren: Which ducts are the ones that pull in the vent air? Are they all the way across the hood at the bottom of the windshield? Or are they concentrated in one area?

 

[SmokeyWren]

[ QUOTE ]
SmokeyWren: Which ducts are the ones that pull in the vent air? Are they all the way across the hood at the bottom of the windshield? Or are they concentrated in one area?

[/ QUOTE ]

I don't know.