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Topic: Dash Heat and air issues (Read 370 times) previous topic - next topic

Dash Heat and air issues

Hi all, hoping you all are having a great summer.

So I only have heat coming out of my dash window defrost vents, no cold air.
No heat coming out of floor or dash vents. Only defrost vents.
Anyone have any ideas ?
James and Suzi
1999 U320  36, Cummins M11
Build 5544  Motorcade #17268
Ronan, Montana
2020 Jeep gladiator

Re: Dash Heat and air issues

Reply #1 –
A vacuum leak or failure defaults to defrost only I think.
Does the AC work?

Frank & Connie Williams
1999 U320 '36
Build: 5466
MC: 18335

Re: Dash Heat and air issues

Reply #2 –
Your blend doors are vacuum actuated.  Your vacuum generator is probably located behind the curtain on your fold up entry step.  If original, it is powered by air from the engine compressor.  There is also a vacuum bottle there.  My original one looked like a large tin can.  It can corrode and leak.  Or it is possible that your blend doors are not working.  I had one of them fail.

If it is your vacuum generator, most people replace the original with an electric one.  There are several threads on the forum.

Rich
Rich and Peggy Bowman
2002 U270 3610 WTFS, build #5939--"Freedom"
2022 Jeep Grand Cherokee Summit 4xe
SMI AirForceOne brake system
PakCanoe 15

Re: Dash Heat and air issues

Reply #3 –
obsolete vacuum generator
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Dash Heat and air issues

Reply #4 –
You can get the blend door actuators from FOT.

Rich
Rich and Peggy Bowman
2002 U270 3610 WTFS, build #5939--"Freedom"
2022 Jeep Grand Cherokee Summit 4xe
SMI AirForceOne brake system
PakCanoe 15

Re: Dash Heat and air issues

Reply #5 –
So my ac blows cold. I can switch to different vents but can't control the temperature. Hot air out of window vent but no ac out of this vent. Is that normal?
Do have cold ac coming out of dash vents but no heat.
James and Suzi
1999 U320  36, Cummins M11
Build 5544  Motorcade #17268
Ronan, Montana
2020 Jeep gladiator

Re: Dash Heat and air issues

Reply #6 –
Quote from: Gold Nugget finder –
Hot air out of window vent but no ac out of this vent. Is that normal?

Are you talking about the little round vents? If so on a '99 320 those may just be for the A/H dash heat.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Dash Heat and air issues

Reply #7 –
Check the vacuum can behind the step flap under the steps..  I replaced mine on my 2000 with a vacuum pump and vac ball. Vac pump is off 90's model ford.....  Got both off of amazon if I remember correctly


Keith
The selected media item is not currently available.Keith & Jo
2003 U320T 4025 PBBS Designer series
Build 6203    Cummins 500hp
2000 U320 4010 WTFE / Build 5762 —Sold—
Motorcade #18070   
Pasadena, Texas
2015 Jeep Wrangler Sahara-Sunset Orange pearl coat
Don't argue with a fool, people watching might not be able to tell the difference.