No heat through vents
10-05-2014, 06:50 PM
#1
Registered User
Thread Starter
Join Date: Mar 2014
Location: N a House
Posts: 18
No heat through vents
Hello to all. I have a problem with no heat coming throught the vents. You can only feel the heat on your feet and the windsheld defroster. Can anybody help me out please.
10-05-2014, 07:31 PM
#2
Registered User
Join Date: Aug 2013
Posts: 1,103
You didn't list your year/model/tranny, etc. Not important? My guess is 1984 AE turbo 5-speed with leopard skin seat covers and fuzzy dice hanging from the rear view mirror. How did I do? Tell the truth. 
Your air distribution system works by way of your vacuum hoses operating dampers inside the dash. It's all laid out in your factory service manual - which you DL free at XenonZ31 Reference
First place to check is the vacuum hoses. They rot and split over time. Here's a diagram from Thumper. Vacuum Lines since you will probably be replacing some. Use the right hose diameter since the system is carefully balanced. The ones inside the dash are critical and hard to get to. Take your time. Replace them one at a time so you don't screw them up. While you're in there, disconnect the harness connectors you find, clean and reconnect them. Corrosion bad.
Check the vacuum pump itself to make sure its working. If it wasn't, the default mode is all your air through the defrost vent. You don't have that, you say. Pump may still be good.
Anyway, there is a floor vent open/close slider switch on the dash closer panel in front of your knees. Slide that switch up and down a few times with the air system on, heating, fan on full speed, and leave it in the down position. See if that changes the system's attitude - before you start checking everything else. Sometimes the dampers just get lazy when the vacuum hoses are leaking.
Let us know how it works out. We like the feedback
Your air distribution system works by way of your vacuum hoses operating dampers inside the dash. It's all laid out in your factory service manual - which you DL free at XenonZ31 Reference
First place to check is the vacuum hoses. They rot and split over time. Here's a diagram from Thumper. Vacuum Lines since you will probably be replacing some. Use the right hose diameter since the system is carefully balanced. The ones inside the dash are critical and hard to get to. Take your time. Replace them one at a time so you don't screw them up. While you're in there, disconnect the harness connectors you find, clean and reconnect them. Corrosion bad.
Check the vacuum pump itself to make sure its working. If it wasn't, the default mode is all your air through the defrost vent. You don't have that, you say. Pump may still be good.
Anyway, there is a floor vent open/close slider switch on the dash closer panel in front of your knees. Slide that switch up and down a few times with the air system on, heating, fan on full speed, and leave it in the down position. See if that changes the system's attitude - before you start checking everything else. Sometimes the dampers just get lazy when the vacuum hoses are leaking.
Let us know how it works out. We like the feedback
Last edited by zxguy1986; 10-05-2014 at 08:22 PM.
10-05-2014, 08:43 PM
#3
Grumpy & Helpful
Join Date: Sep 2006
Location: Mill Creek WA
Posts: 1,415
if you would really like answers that would help you and avoid flames give the following info when you post: year of car, n/a or turbo engine, stick or slushbox. Most of us can tell by the year what model you have ie 85T is a turbo z31. Z cars come in many flavors and they are all different. example 84,85,86 Z31's pretty comparable. there were changes in 87,88,89. in addition 300ZX can refer to two completly different cars the Z31 and the Z32. No mindreaders here the more info you can post the more likely you get a cogent useful answer. The cars with L engine (straight six) changed almost yearly from their introduction. A 240Z and and a 280Z have similarities but they can also have wide variance.
10-06-2014, 07:30 PM
#4
Registered User
Join Date: Jul 2008
Location: Florida
Posts: 154
Either vacuum lines or actuators under the dash are bad.
2 more helpful sites
Tom's z31 300ZX Page
Robo
2 more helpful sites
Tom's z31 300ZX Page
Robo
10-07-2014, 05:10 PM
#6
Registered User
Join Date: Aug 2013
Posts: 1,103
Well, my guess was close... 
Hey, keep us updated on your work there and let us know when you get it the way you want it and what you did to get it that way! We love the feedback and others get helped by it! Thanks. 
Our Z pros will definitely have some input for you. Meanwhile, do yourself a favor. Sign in, go to User CP menu (upper left), click Edit Signature and add your Z model, year, shifter, turbo or NA, etc. Saves you having to add it to every post. (Guys here go crazy if you don't lock your Q to your specific Z every time you post...They just ignore questions without enough info) Then click Edit Avatar and add a little Z pic under your nick if you want. Cool. You are solid here.
Thanks again.
Hey, keep us updated on your work there and let us know when you get it the way you want it and what you did to get it that way! We love the feedback and others get helped by it! Thanks. Our Z pros will definitely have some input for you. Meanwhile, do yourself a favor. Sign in, go to User CP menu (upper left), click Edit Signature and add your Z model, year, shifter, turbo or NA, etc. Saves you having to add it to every post. (Guys here go crazy if you don't lock your Q to your specific Z every time you post...They just ignore questions without enough info) Then click Edit Avatar and add a little Z pic under your nick if you want. Cool. You are solid here.
Thanks again.
Last edited by zxguy1986; 10-07-2014 at 05:15 PM.
02-10-2015, 03:30 PM
#7
Registered User
Join Date: Jan 2015
Location: Bellevue, WA
Posts: 51
You didn't list your year/model/tranny, etc. Not important? My guess is 1984 AE turbo 5-speed with leopard skin seat covers and fuzzy dice hanging from the rear view mirror. How did I do? Tell the truth.
Your air distribution system works by way of your vacuum hoses operating dampers inside the dash. It's all laid out in your factory service manual - which you DL free at XenonZ31 Reference
First place to check is the vacuum hoses. They rot and split over time. Here's a diagram from Thumper. Vacuum Lines since you will probably be replacing some. Use the right hose diameter since the system is carefully balanced. The ones inside the dash are critical and hard to get to. Take your time. Replace them one at a time so you don't screw them up. While you're in there, disconnect the harness connectors you find, clean and reconnect them. Corrosion bad.
Check the vacuum pump itself to make sure its working. If it wasn't, the default mode is all your air through the defrost vent. You don't have that, you say. Pump may still be good.
Anyway, there is a floor vent open/close slider switch on the dash closer panel in front of your knees. Slide that switch up and down a few times with the air system on, heating, fan on full speed, and leave it in the down position. See if that changes the system's attitude - before you start checking everything else. Sometimes the dampers just get lazy when the vacuum hoses are leaking.
Let us know how it works out. We like the feedback
Your air distribution system works by way of your vacuum hoses operating dampers inside the dash. It's all laid out in your factory service manual - which you DL free at XenonZ31 Reference
First place to check is the vacuum hoses. They rot and split over time. Here's a diagram from Thumper. Vacuum Lines since you will probably be replacing some. Use the right hose diameter since the system is carefully balanced. The ones inside the dash are critical and hard to get to. Take your time. Replace them one at a time so you don't screw them up. While you're in there, disconnect the harness connectors you find, clean and reconnect them. Corrosion bad.
Check the vacuum pump itself to make sure its working. If it wasn't, the default mode is all your air through the defrost vent. You don't have that, you say. Pump may still be good.
Anyway, there is a floor vent open/close slider switch on the dash closer panel in front of your knees. Slide that switch up and down a few times with the air system on, heating, fan on full speed, and leave it in the down position. See if that changes the system's attitude - before you start checking everything else. Sometimes the dampers just get lazy when the vacuum hoses are leaking.
Let us know how it works out. We like the feedback
04-26-2015, 08:47 PM
#8
Registered User
Join Date: Apr 2015
Location: Iowa
Posts: 30
I had the same problem. Mine was cracked vacuum line ends both at the collector near the right headlight and at the end where the line enters the cabin through the firewall. Quick fix to see if that is the issue is to cut off 2" or so on the end of the vacuum lines and re-attach the hose to the nipples on the collector and splice point. If this fixes the issue you win and can either run with what you have, on borrowed time, or replace the vacuum line. This is the easiest initial troubleshooting step for this issue and doesn't require tearing into the dash or anything.
Thread
Thread Starter
Forum
Replies
Last Post
Bookmarks
