Like a lot of late model F150 owners... I have never been pleased with the A/C in my 2004 F150 Scab... at best on a cool day it would blow only 49 degress with MAX A/C in Recirc mode... on FAN 4
Meanwhile my 2000 F150 will blow 37 degrees when its 110 out...

Ive done tons of research on this problem ... being that I live in Phoenix.. and it was 115 out today... and as Im driving around in my $30,000 truck beads of sweat are dripping out....

anyways what Ive noticed for a while now.... is that the heater core is always hot... there is no shutoff valve's on the heater hose inlet to disable the heater when you run the A/C..... so even though the airflow is bypassing the heater core... the heater core itself it still hot as hell inside your cab and radiating heat into cab....

so I went to home depot... bought a 1/2 ball valve... and a 1/2 x 6in long brass nipple..

I then cut the nipple right in half... making two pieces... ( one side without threads which I used as the hose side.. after rounding sharp edges off)


now thread your two halfs into the ball valve... and cut heater hose (inlet side) in a nice straight area out of the way .. and insert ball valve inline of heater hose.. add a couple hose clamps...


anyways .. I just did a road test

with a thermometer in one of the middle vents... the lowest temp it would read today was 50 degrees driving down freeway.. ( temp gauge on dash read 115 ).. and it would go up to as high as 60 in town.. stop and go...



now an hour later with shut off valve inline of heater hose... it is reading 39 degrees... dash temp still said 115 while driving down freeway... and in town it didnt go above 45...


That is much more like it!.... Why would ford design such a stupid system is beyond me... my ole 80 toyota pickup had an inline heater control valve... that is where I got the Idea... just baffled on why I didnt do this 3 years ago...

 

How about some pics of your hard work?

 

interesting! good detective work finding that :-)

 

Do you think there will be any negative side affects?

 

Just that you have to remember to turn on the valve when you want heat.

 

Ok here is a quick pic... I removed handle from valve though it looks much better without it...

also there are many Heater control valves on the market for other vehicles that could be used.. most run off vacumn
but I didnt want to mess with my vacumn lines... I only use the heater like 3 times a year... and its just a quick 1/2 turn and heater is back on...


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Keep us updated on how it works...

 

Standard stuff in the Super Duty/Excursions since 04 I think. Odd that they didn't add it to the F-150's.

My 05 Excursion's valve.

 

Nice post, good info.

 

That is a great idea, I intend to try it this weekend to see the difference for myself.

 

Ummm...isn't that hose hooked directly to the top of your t-stat???!? Doesn't look like there's a bypass there either....Can you say S-T-E-A-M??? Or BLOWN as in radiator, since it's the weakest link next to a hose?

 

The t.-stat is at the intake manifold end of the upper rad. hose.

 

Ha...you're right, and I'm WRONG. I'll pull that and take a look at what's under there tonight. It doesn't look like something you want shut off.

 

Yep, I added a heater shut-off valve...but it's vacuum operated and draws vacuum when I put the AC on MAX/Recycle .

 

Cool, how about some instructions and pics of what you did?

Also, doesn't interrupting that inlet tube stop the circulation of the coolant to the whole system? I'm guess no because the OP's car hasn't overheated. I can't seem to locate a coolant flow diagram in the service manual.