ynk1121

Alright all knowing Corvette Forum... It's a 95 Lt1 with the electric HVAC controls. Recirculate button lights up for a second when pressed and then goes off. Tried every combination of buttons but it won't stay on. Checked it for codes and no codes are being thrown. I'm assuming it's the door up in top right passenger footwell? Checked the door and it isn't stuck or anything. I can move it with my hand. Not sure how much vacuum or whatever should come from the line but I tried removing the orange tube and I feel and hear nothing (although it's cold out and the exhaust is loud). Any ideas?

Cliff Harris

Run the HVAC diagnostics to see if there is anything there:

ynk1121

Thanks for the reply. I tried that. No blinking or codes being thrown.

pcolt94

You have bad solder connections behind the LEDs on the printed ckt board. It requires the head unit to be removed and disassembled. I have been doing this for years and there is a thread on it and see if I can find it.

In short after you get the cover off, the main board unplugs with 1 connector. Then you remove the 4 front screws, remove the board and rubber button contactor. Careful with the buttons and LEDs. Then solder the board up especially where it problem area is. Go slow, don’t overheat or let anything (leads) move.

If you're talking about the blend door it is very quiet and is motor driven. It should not move at all freely. If you want to see if it moves, remove the module from the top of the evaporator and look in with a flashlight. Set (key ON) the temp to 60 and check door, then set to 90 and check door. If it moves from side to side (90 deg) then it is OK.

ynk1121

Does the solder connection you are describing affect functionality or is it usually a case where the light just doesn't light? I have no change in airflow when pressing the button yet it definitely knows I'm pressing it because it lights for a couple seconds.

I'm not sure how to better describe it. The little door I'm taking about is on the passenger side, if you follow the sill forward until it meets the firewall. Like forward of the speaker and slightly higher. It's vacuum activated. There is an orange tube going to it. I assume it's what's supposed to move when recirculate is turned on?

RollaMo-LT4

Is it below freezing outside when your trying this?

ynk1121

Now that's interesting. I recall it was saying it was 37F on the controller when I was trying it. While that's obviously above freezing I'm wondering if it was too close to freezing that it's purposely not working? Any idea what sensor(s) it's using to determine that? I think I'm going to wait until we get into the 40s before I go crazy tracking down an issue that doesn't exist. Thanks. I'll report back if Spring ever shows up here.

ynk1121

Thanks, you were 100% right on this. As long as the outside temperature were at least in the 40Fs it works perfectly.