Need advice asap please

Reply Subscribe

Thread Tools

Search this Thread

Jun 30, 2022 | 03:12 AM

JohnnyGaloshes

Thread Starter

Cross-Country

Joined: Sep 2015

Posts: 52

Likes: 2

From: Perth Andover

Need advice asap please

2018 f350 xlt 6.7

Ok so i am a Hotshot driver and i have developed a problem with my air circulation today. When i switch from dash to vent to floor, that works fine. The blower motor seems to be blowing at normal strength and works a normal through the speeds, no noise from motor either. But the problem is that the air coming out of any position (dash, vent or floor) or cut to maybe 25%. The cabin air filter is almost new so i can eliminate that. Also the recirculation works fine also. I am thinking actuator but if it goes from dash, vent and floor ok, then it can't be the actuator. Unless the is another that routes the air completely.i had the ac compressor replaced about a month and a half ago and has been working great, but now it's not as cold.

It sounds like it is blowing hard behind passenger side dash, but isn't going farther across the dash to the driver side. All vents have same poor air flow, no matter which i open.

I sleep in my truck and i need this fixed asap or i will roast. Any help is appreciated!!

Last edited by JohnnyGaloshes; Jun 30, 2022 at 03:24 AM. Reason: Adding to symptoms

Jun 30, 2022 | 05:24 AM

JohnnyGaloshes

Thread Starter

Cross-Country

Joined: Sep 2015

Posts: 52

Likes: 2

From: Perth Andover

After some investigating i noticed the pipe going into the firewall for the ac evaporator was frozen solid. I think that is the culprit as i thawed it and blowing strong now. The frozen ev must have been restricting the flow through.

Jun 30, 2022 | 06:52 AM

JohnD333

Laughing Gas

Joined: Aug 2008

Posts: 832

Likes: 110

There are reports that a high quality hepa-type cabin filter impedes air flow too much even when brand new, even more so as it collects dust etc. If that is what is “almost new,” try replacing it with a simple paper filter. Oem would be a sure test.

Also if ac was serviced recently, it could have been overfilled. This does cause system freeze. Ac shuts down until it thaws out naturally, restarts, freezes, repeat. If not serviced or topped off since last hot season, ignore.

Jun 30, 2022 | 07:02 AM

Ltngdrvr

Lead Driver

Joined: Nov 2005

Posts: 8,458

Likes: 4,955

Quote:

Originally Posted by JohnnyGaloshes

Yeah, sounds like the evap is getting iced over.
That would indicate improper freon charge/leak or possibly a bad pressure switch.
If it was recently serviced, then I would say take it back to that shop, they didn't do it right or they left it leaking.

Jun 30, 2022 | 08:49 PM

sleddinfool

Mountain Pass

Joined: Sep 2020

Posts: 109

Likes: 23

There is a tech service bulletin to replace the heater case for that.. The evap temp sensor stops operating correctly and the compressor never cycles off, hence the evaporator freezing.