No ac coming from dash vents
- Thread starter mschuitt
- Start date
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Ray-IN
Well-known member
Leaking/ broken vacuum hose. When vacuum is lost the default position for air movement is to the defrosters.
This is not easy to find, you can't spray soapy water of these hoses to find a leak. Close visual inspection is required; or the easy way is to simply buy enough new hose to replace them all.
This is not easy to find, you can't spray soapy water of these hoses to find a leak. Close visual inspection is required; or the easy way is to simply buy enough new hose to replace them all.
whiteva
Well-known member
In addition to the hoses I needed to change the vacuum box. Check out this video.
The dealer wanted almost $900.00 for repairs. following this video I made the repair for less than 30 bucks. Still working 3 years later.
Good luck friend.
The dealer wanted almost $900.00 for repairs. following this video I made the repair for less than 30 bucks. Still working 3 years later.
Good luck friend.
If it is caused by a vacuum leak it is relatively easy to fix. If it is a sticking mix control door under the dash it is a complicated job requiring disassembling components under the dash, which is a major pain and not for the faint of heart.
First find the vacuum line under the hood going thru the firewall or sometimes between the inner and outer fender. Mine was 1/16" red plastic on the passenger side. With the engine running see if the line under the hood has vacuum. Some have a metal junction on the firewall where you can pull off the line to test. If not you may have to cut the line to test but it can be spliced back together later with 1/16" inside diameter rubber vacuum line. If there is no vacuum then your problem is under the hood not under the dash. Trace the line under the hood to see if you can find the vacuum reservoir which may be a round ball with various vacuum lines attached. If the reservoir has vacuum just run a new line back to where you cut it. If not trace from the reservoir back until you find the leaky vacuum line. My reservoir was hidden where I could not see it if so I just teed into a line which had vacuum and melted the end of the leaky line shut.
If there is vacuum going inside the cab you'll need to trace the line under the dash. If you're lucky you may find a break in the line without disassembling the climate control.
First find the vacuum line under the hood going thru the firewall or sometimes between the inner and outer fender. Mine was 1/16" red plastic on the passenger side. With the engine running see if the line under the hood has vacuum. Some have a metal junction on the firewall where you can pull off the line to test. If not you may have to cut the line to test but it can be spliced back together later with 1/16" inside diameter rubber vacuum line. If there is no vacuum then your problem is under the hood not under the dash. Trace the line under the hood to see if you can find the vacuum reservoir which may be a round ball with various vacuum lines attached. If the reservoir has vacuum just run a new line back to where you cut it. If not trace from the reservoir back until you find the leaky vacuum line. My reservoir was hidden where I could not see it if so I just teed into a line which had vacuum and melted the end of the leaky line shut.
If there is vacuum going inside the cab you'll need to trace the line under the dash. If you're lucky you may find a break in the line without disassembling the climate control.
Bobtop46
Well-known member
I had this same problem with my Workhorse W22. Went under the hood and found disconnected 2" duct line, and cracked (plastic) vents where the 2" duct line connects. I've had no luck finding replacement vents. I was able to replace the 2" duct line with flexible plastic duct line, restoring dash air conditioning. Inside under the dash the 2" plastic duct line has terrible routing and I would like to redo it all. I have been searching for insulated 2" duct line to replace all of the duct lines I have under the hood and under the dash. This goes for defroster ducts as well.
Picture going down the road in Texas during the summer (105 degrees) with your dash AC on full bore. The AC is making cold air that is then piped via 2" plastic flexible duct under the hood with the outside heat and engine heat, warming the cold air. We get condensation under the dash on the passenger side due to poor routing and thin plastic flexible vents. Think cheapest slinky for the the black tank, but in 2".
Picture going down the road in Texas during the summer (105 degrees) with your dash AC on full bore. The AC is making cold air that is then piped via 2" plastic flexible duct under the hood with the outside heat and engine heat, warming the cold air. We get condensation under the dash on the passenger side due to poor routing and thin plastic flexible vents. Think cheapest slinky for the the black tank, but in 2".
WME
Well-known member
Lots of 4" maybe use that as a sleeve over your 2"
I was thinking it would be electric actuators that controlled the doors, but looking on my shop information it is vacuum motors.
Natetheskate
Well-known member
- Joined
- Jun 23, 2007
- Posts
- 157
I had the same issue, but had to get another vacuum tank, since it is very difficult to get to on those models. But I was able to run another line through the firewall where the old line went. A bit of work, but it looks very good.
