air mix/temperature door?
Thread Starter
Intermediate
Joined: Nov 2007
Posts: 30
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From: Metter Georgia
air mix/temperature door?
I have an '89 Corvette convertible. The air mix door does not open or close. I took the programmer out and the resistors appeared to have gotten hot. The local Radio Shack dealer was unable to determine the value of the resistors. What are these values, ohms, watts and tolerance? How do I test? Where can I purchase these resistors?
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
I have a spare programmer at work. I will see what the resistance colors are.
My guess is they are 1 watt resistors. but I don't know what the resistance is.
Um, in any case, I don't know if the resistors are for the door.
I think they may be in the circuit that changes the speed of the blower.
My guess is they are 1 watt resistors. but I don't know what the resistance is.
Um, in any case, I don't know if the resistors are for the door.
I think they may be in the circuit that changes the speed of the blower.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
resistors
I don't have my resistor value chart handy, but here goes:
brown, gold, brown, with a silver (i think) 10% tolerance band.
and they are indeed 1 watt resistors.
i should think a ceramic resistor would hold up much better.
brown, gold, brown, with a silver (i think) 10% tolerance band.
and they are indeed 1 watt resistors.
i should think a ceramic resistor would hold up much better.
Safety Car
Joined: Jan 2004
Posts: 3,759
Likes: 8
The door is probably just stuck. I had the same problem when I got my 89. I would get AC, but when I turned to heat, I could tell I had heat, but it wasn't blowing. Looked through the resistor hole, and noticed the temp door didn't change when I turned from AC to heat and vice versa. I stuck a screw driver in the hole to move the door as that seemed to unstick it. Might be easier to just pull the blower motor to get in there.
Though, one problem I have is when I'm in Auto and turn the temp up to 90, it seems to shut the doors into defrost or something. In order for me to get heat through the vents I have to have it set to Bilevel. I never figured that out.
Though, one problem I have is when I'm in Auto and turn the temp up to 90, it seems to shut the doors into defrost or something. In order for me to get heat through the vents I have to have it set to Bilevel. I never figured that out.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
For my '88 the resistances are:
.....A.......C........D.......B
----/\/\/\--/\/\/\--/\/\/\-----
A-C = 1.5 Ohms
C-D = 0.7 Ohms
D-B = 0.2 Ohms
Yel = wire into A
Tan = wire into C
Lt Blu = wire into D
Dk Blu = wire into B
Using P = I*V & V = I*R or P = V**2 / R and assuming a max voltage of say 15Vdc, you can calculate the wattage required for each resistor.
With the blower speed set to:
Lo = power through Yel wire and all resistors
M1 = power through Tan wire and C-D + D-B resistors
M2 = power through Lt Blu wire and D-B resistor
Hi = full battery voltage applied to blower motor
.....A.......C........D.......B
----/\/\/\--/\/\/\--/\/\/\-----
A-C = 1.5 Ohms
C-D = 0.7 Ohms
D-B = 0.2 Ohms
Yel = wire into A
Tan = wire into C
Lt Blu = wire into D
Dk Blu = wire into B
Using P = I*V & V = I*R or P = V**2 / R and assuming a max voltage of say 15Vdc, you can calculate the wattage required for each resistor.
With the blower speed set to:
Lo = power through Yel wire and all resistors
M1 = power through Tan wire and C-D + D-B resistors
M2 = power through Lt Blu wire and D-B resistor
Hi = full battery voltage applied to blower motor
