Is Heater supply line reversed ? poor AC

[donr103]

You can switch them around if you want.. while you are doing that.. go on line at favorite store or go into auto parts store and grab a book on basic automotive a/c and they will lend you gauges for free.. but in 50yrs I never found it to make much difference.. think about it.. these light duty truck eng run at 195 degrees.. doesn't matter which heater line is where.. I know from factory they do go certain way.. and later service could mix them up.. by all means.. go ahead and try.. I would like to know what you find out.. it's easy enough.. and you will not hurt anything.. you asked for some opinions.. so ignore 50yrs and try it.. if I were you.. I would get some gauges on a/c and save you back.. it most likely just 4.00 low on Freon.. but if you feel like switching lines ok.. now if you were now getting enough heat.. maybe that would help.. but your 1st complaint is not getting cold enough.. so good luck and let us know what you did and maybe better members then me will help you

[donr103]

Oh one thing I found that helps.. is while you are switching lines.. try to just bypass heater core altogether.. just get a barb hose connector and put them together.. that helps a lot.. but just read a post.. not enough heat insulation in dog house and eng and hvav box.. yes I found that great help.. I added 20 boxes.. did everything.. tip.. use thicker stuff.. with aluminum coated.. I use 80mm 1st.. too little.. went over that with 350mm. Use 350mm when and where you can.. following instructions.. good luck and keep us posted..

[sevenmacs]

Yes, I read the bulletin, thats why I'm switching them. It should be the same on my fleetwood I assume.

[sevenmacs]

Originally Posted by mack73

I've got a '21 bounder with everything working well. Send me a PM with some pics of how your hoses are routed and I can compare them with mine tomorrow.

Thanks that would help greatly, photo attached

[mack73]

Just replied to your PM. Based on how mine are routed, yours are indeed backwards

The line with the valve is connected to manifold. The line without the valve goes to the water pump

[sevenmacs]

Originally Posted by mack73

Just replied to your PM. Based on how mine are routed, yours are indeed backwards

The line with the valve is connected to manifold. The line without the valve goes to the water pump

I replied with a PM, not sure it went. Wanted to thank you, that was above and beyond especially that quick and this late.

Like I said contrary to what some have said it does matter where supply comes from. This is per the heater manufacter, valve can't handle backward flow. Only problem is they said it can be damaged by reversed flow, I'll have to test it.

Thanks greatly !!!

[sevenmacs]

Swapped the lines and everything is working fine now. Also received a call from Ford technician for F53 chassis and he confirmed that the lines were backwards.

[THenne1713]

Some have water valve, some just move air flow doors? If hot both sides= water flowing, PINCH off heater hose and see if it helps the air temp?

[sportcoupe]

New here and a friend pointed me here for my hot AC driving. I have a 2022 Thor Vegas on Ford E350 chassis (7.3L). I swapped hoses at water valve and AC is cold driving now.

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[donr103]

Well I guess I was wrong on this one.. not the 1st time.. great job guys.. I would have never thought of it.. I stand corrected.. thank you.. for teaching old dog new tricks.. I remember just a few times in the past it made a difference.. but on these new coaches.. it does.. it is so easy to get them backwards.. and it used to make no difference.. so it was not me.. but who ever at the plant is installing them... must be my twin.. or older guy that just does not understand it makes a difference.. so I hope that where new members read this.. yes.. position on these heater hoses makes a difference according to members above.. so start there 1st.. sorry for any confusion.. and thank you to all that kept working on the problem.. good luck and keep us posted

[Xmcdog]

Hi Donr103.
You have a few more yrs in than I. Got into refrigeration in 74 and enjoyed a great career. One sees new problems on a regular basis it seems and I'm still learning. Lol.

Glad to see the OP and others have found the issue. It was an interesting one for sure.

[THenne1713]

My little D21 4-cyl Nissan truck RADIATOR HOSES always looked backwards to me, but could see no way to reverse them w/ the factory hoses; always a big, big, big pain to bleed air from system to get heat, too... guess pumping into the top of coil makes it rather hard to bleed air... (maybe) I shudda been concentrating on heater hoses vs radiator

[TFell]

My 2021 Fleetwood Flair 29M was exhibiting the same issues. AC works when the engine is cold, then starts blowing hot air as it warms up.

I first called the Ford dealer before reading on here that it is not a Ford issue. They told me it is a motorhome manufacturer issue and that they have had a few of the same complaints. General RV initially told me it was a Ford issue until I convinced them it is likely the hoses and got transferred to their Service Advisor Team Lead. Took it in today and they concluded that the lines are indeed reversed...being fixed now.

Thanks to the forum, I was educated on the likely cause.

[leroygfy]

Originally Posted by sevenmacs

Swapped the lines and everything is working fine now. Also received a call from Ford technician for F53 chassis and he confirmed that the lines were backwards.

Where did you swap lines, on the heater core?