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2002 C5Z - LS3 swap. AIR delete.
There is no code in the HVAC stored.
When I select the vents, the light changes from high, top, to dash.
The air blows cold. It switches from recirculate to outside air just fine.
Read something about vacuum being used to drive the vents. However - I have deleted the AIR pump, so I'm not sure if this is still possible?
If I need to make a modification of a hose or just make a new one, I can do that but I don't know where to start. It's using a stock LS3 manifold.
Thanks!
Last edited by nocopnostopp; Sep 11, 2023 at 09:29 PM.
I'm having the same issue. Have you tried calibrating the blend doors first? I don't know how to copy an entire thread into a new one but here is some of the information I received from C5 diag. I am bring my vette to the dealer next monday to check it out.
Copied from another post:
Turn off the ignition.
Remove the Fuse of the HVAC control module located in the floor of the pass. side fuse box (fuse #27 only). There is another HVAC fuse (don't recall the #), it does not need removing.
Important: The module memory will not clear if the fuse is re-installed in less than 60 seconds (59 won’t reset it & you don't have to wait 5 minutes either). Wait 60 seconds minimum.
Re-install #27 fuse.
Start car, turn on AC
Blend doors pretty much just change the temperature, not the air path. Air path actuators run on manifold vacuum -- but so does the fresh/recirculated air valve. If you can switch between fresh and recirculated, then you must have a vacuum source.
Changing from fresh to recirculated should have two effects, first the light should cycle on and off with the switch, and second apparent air flow should increase when in recirculate mode. If the light comes on, but the air flow volume doesn't go up, then you may not actually be changing.
Blend doors pretty much just change the temperature, not the air path. Air path actuators run on manifold vacuum -- but so does the fresh/recirculated air valve. If you can switch between fresh and recirculated, then you must have a vacuum source.
Changing from fresh to recirculated should have two effects, first the light should cycle on and off with the switch, and second apparent air flow should increase when in recirculate mode. If the light comes on, but the air flow volume doesn't go up, then you may not actually be changing.
You're right actually I am not even sure the mode is actually changing from fresh and recirculating, it's just changing the light on the controller.
So how do I give it a vacuum source if I do not have an AIR system? what vacuum should I run from where to where? can anyone draw me a diagram? I deleted that system a long time ago but forgot what was involved.
Originally, there was a small vacuum reservoir and check valve in the recess behind and beneath the battery in the r/h fender. There was/is a semi-rigid plastic tube within the wiring harness that runs across the firewall from near the reservoir to the nipple on the center rear of the intake manifold.
All you have to have is a vacuum line running from the nipple on the manifold to the line coming out of the cabin. A reservoir and check valve in line will keep the air path steady during high throttle/low manifold vacuum situations, but mine have been bypassed for several years.
Originally, there was a small vacuum reservoir and check valve in the recess behind and beneath the battery in the r/h fender. There was/is a semi-rigid plastic tube within the wiring harness that runs across the firewall from near the reservoir to the nipple on the center rear of the intake manifold.
All you have to have is a vacuum line running from the nipple on the manifold to the line coming out of the cabin. A reservoir and check valve in line will keep the air path steady during high throttle/low manifold vacuum situations, but mine have been bypassed for several years.
Thanks, where is the line coming out of the cabin? I guess regular vacuum line and zip ties will do?
Thanks, where is the line coming out of the cabin? I guess regular vacuum line and zip ties will do?
It's been so long since I worked on mine, I honestly do not recall. I believe there are photos here on the forum that I may have copied along the way. I do recall that the feed through is in the same recess as the reservoir, so requires removal of the battery, and I almost think I had to pull the battery tray as well.
It took me a full year (and 5 years since I swapped the motor). I simplified the tubing since I no longer have the AIR system installed. The vacuum source plugged right into the LS3 intake I have in the car.
C5 won't change vent. Stuck on Dash vent no codes
