max ac not working

[jdsr]

Why would max ac blow out defrost and not vent. It will blow out vent foa a few seconds but then stops

[jdsr]

Why would max ac blow out defrost and not vent. It will blow out vent foa a few seconds but then stops

[M&EM]

JDSR,
Intersting you have the same problem I just experienced on my rig.

This is what I did to fix it.
On the passenger side of my dash about where the passenger feet would be is a vacuum actuator with 2 vacuum hoses going to it. Each of these vacuum lines has a 90 degree rubber fitting that adapts to and slips onto the vacuum actuator ports. If these 90 degree fittings are pushed on too far, they seem to block them selves up. I discovered this while messing with the hoses to see if they were detached while the engine was running. Sure enough I could easily block the vacuum path by pushing the fittings too far. One was in that state due to easy exposure to the ports to someones outstretched feet. By simply wiggling the fitting slightly back, everything started to work again.

Marty

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jdsr:
Why would max ac blow out defrost and not vent. It will blow out vent foa a few seconds but then stops </div></BLOCKQUOTE>jdsr, Have you or are you able to roll your dash up. What happens if you are not careful is the vacuum lines become dislodged from the back of the selector switch. First thing make sure all those vacuum lines are connected.

[jdsr]

thanks for the tips. I will check both tomorrow.One more question. If the line or lines were disconnected would it still work on max air for a few seconds before coming out of the dash?

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jdsr:
thanks for the tips. I will check both tomorrow.One more question. If the line or lines were disconnected would it still work on max air for a few seconds before coming out of the dash? </div></BLOCKQUOTE>jdsr, Not exactly sure about scenarios however I can share with you what I have found to be problematic with the selector switch when the vacuum lines are not properly secured.

[jdsr]

ok, I go check the max ac and of course its working. I looked at the switch and there are 5 hoses attached and a place for another hose. Should there be a vacant slot and what color hose controlles the max ac. I swear the max ac has not worked more than 15 seconds in the last 6 months and know it wont quit. One thing I have noticed now is with fan on high theres no differance in fan speed on max or reg ac.

[jdsr]

another question, with ign on but engine not running should fan still blow on vent, ac, and max. It does on my truck but doesnt on mh. This could be something, I dont know

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jdsr:
One thing I have noticed now is with fan on high theres no difference in fan speed on max or reg ac. </div></BLOCKQUOTE>I'm a little confused by the question. When your control is on "MAX AC" it can not be on "REG" at the same time.

The fan speed is variable using the speed switch for both modes. The REG just allows outside air to enter the cabin.

There is a modular plug on the back of the speed switch. Mine comes off all the time. make sure you've pressed the plug firmly on the base.

When you turn the key "ON" - "Yes" the blower motor should work without the engine running. I just took a look at my selector switch. 5 lines and one open port, "Normal"

[Tom N]

-Tom

[jdsr]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DriVer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jdsr:
One thing I have noticed now is with fan on high theres no difference in fan speed on max or reg ac. </div></BLOCKQUOTE>I'm a little confused by the question. When your control is on "MAX AC" it can not be on "REG" at the same time.

The fan speed is variable using the speed switch for both modes. The REG just allows outside air to enter the cabin.

There is a modular plug on the back of the speed switch. Mine comes off all the time. make sure you've pressed the plug firmly on the base.

When you turn the key "ON" - "Yes" the blower motor should work without the engine running. I just took a look at my selector switch. 5 lines and one open port, "Normal" </div></BLOCKQUOTE>driver, on my veh's with fan on high and I switch from ac to max ac I notice more fan speed(or noise) and what seems like more cold air coming out vents. Also the blower motor will work with key on and engine off in ac but not max ac. Do you know which hose controls max ac?

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jdsr:
driver, on my veh's with fan on high and I switch from ac to max ac I notice more fan speed(or noise) and what seems like more cold air coming out vents. </div></BLOCKQUOTE>jdsr, What you are relaying to me me is a normal fan and MAX A/C discharge. Dats what it spoda du!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Also the blower motor will work with key on and engine off in ac but not max ac. Do you know which hose controls max ac? </div></BLOCKQUOTE>Not sure what's up with that but if everything is working with the engine running, I'd go with that for the moment.

Looking forward to seeing you at the Rally here in October.

[jdsr]

the fan blows more air and colder air on max than on reg ac in my other veh but not my mh is what I should of said. So when it decides to work on max in my mh it is not working properly. Do you or anyone else know which hose controls the max ac. From what I see on the drawing there are 2 hoses connecting to pos 1 but thats not what I have on my switch. Any ideas? the tech at winn didnt know which hose controls max air

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jdsr:
From what I see on the drawing there are 2 hoses connecting to pos 1 but thats not what I have on my switch. Any ideas? the tech at winn didn't know which hose controls max air </div></BLOCKQUOTE>Which color tubes are on which positions on your selector switch? Your controls should be little different than mine if at all.

Hope that someone out there with better expertise can figure it out.