95 a/c temp blend door
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
95 a/c temp blend door
Automatic a/c
battery disconnect for 1 min.
Diagnostic trouble code shows 00. in any of the ac or heat modes. Parameter 34 (temp door position request) -153 full cooling to 00 full heat working properly
Parameter 24 (temp door actual position ) stays on 138 (not 128)
no matter what the temp setting is, yet no trouble codes ??
Thanks for your help
battery disconnect for 1 min.
Diagnostic trouble code shows 00. in any of the ac or heat modes. Parameter 34 (temp door position request) -153 full cooling to 00 full heat working properly
Parameter 24 (temp door actual position ) stays on 138 (not 128)
no matter what the temp setting is, yet no trouble codes ??
Thanks for your help
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
a/c is cold til motor warms up.
Is the position potentiometer on the blend door motor or on the blend door? Thanks
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
The potentiometer is a part of the temp door motor. Can you hear any noise (clicking/popping ) from the temp door motor? I had a code in mine when it went bad, but it also had a faint noise (gear in the motor was cracked) when I tried to adjust the temperature.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
Funny that no error code when my actual position reading (parameter 24)and asked for position (parameter 34) don't match, I would think that the computer would compare the two readings, maybe not.
Still trying to figure how to remove dash air vent cover to get to bolt holding knee bolster. (Service manual not clear on how to remove)
Melting Slicks
Joined: Feb 1999
Posts: 3,261
Likes: 9
From: sonoma ca
Tried temp adjust with engine off to try to hear. No noise when temp adjust. Does the gear also move the potentiometer?
Funny that no error code when my actual position reading (parameter 24)and asked for position (parameter 34) don't match, I would think that the computer would compare the two readings, maybe not.
Still trying to figure how to remove dash air vent cover to get to bolt holding knee bolster. (Service manual not clear on how to remove)
Funny that no error code when my actual position reading (parameter 24)and asked for position (parameter 34) don't match, I would think that the computer would compare the two readings, maybe not.
Still trying to figure how to remove dash air vent cover to get to bolt holding knee bolster. (Service manual not clear on how to remove)
You can then remove the unit & have access to the bolts holding the lower trim panel in place.
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
IIRC there are multiple gears in the motor assembly and the potentiometer is a part of the assembly. As far as the vent goes there is a cover in the center of the vent approx. 2 x 3 inches in size. It has locking tabs and snaps in and out. The tabs break easily 
--I had to replace mine. There are screws which hold the vent assembly in place once you remove the cover you'll see them. You'll also see the in car temp sensor when you remove the vent cover.
Are you sure the AC system is charged correctly and have you removed the blower control module in the evaporator housing and looked at the temp door while someone else operates the controls to see if the door is going from max heat to max cold?
--I had to replace mine. There are screws which hold the vent assembly in place once you remove the cover you'll see them. You'll also see the in car temp sensor when you remove the vent cover.Are you sure the AC system is charged correctly and have you removed the blower control module in the evaporator housing and looked at the temp door while someone else operates the controls to see if the door is going from max heat to max cold?
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
IIRC there are multiple gears in the motor assembly and the potentiometer is a part of the assembly. As far as the vent goes there is a cover in the center of the vent approx. 2 x 3 inches in size. It has locking tabs and snaps in and out. The tabs break easily --I had to replace mine. There are screws which hold the vent assembly in place once you remove the cover you'll see them. You'll also see the in car temp sensor when you remove the vent cover.
Are you sure the AC system is charged correctly and have you removed the blower control module in the evaporator housing and looked at the temp door while someone else operates the controls to see if the door is going from max heat to max cold?
--I had to replace mine. There are screws which hold the vent assembly in place once you remove the cover you'll see them. You'll also see the in car temp sensor when you remove the vent cover.Are you sure the AC system is charged correctly and have you removed the blower control module in the evaporator housing and looked at the temp door while someone else operates the controls to see if the door is going from max heat to max cold?
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Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
IIRC there are multiple gears in the motor assembly and the potentiometer is a part of the assembly. As far as the vent goes there is a cover in the center of the vent approx. 2 x 3 inches in size. It has locking tabs and snaps in and out. The tabs break easily --I had to replace mine. There are screws which hold the vent assembly in place once you remove the cover you'll see them. You'll also see the in car temp sensor when you remove the vent cover.
Are you sure the AC system is charged correctly and have you removed the blower control module in the evaporator housing and looked at the temp door while someone else operates the controls to see if the door is going from max heat to max cold?
--I had to replace mine. There are screws which hold the vent assembly in place once you remove the cover you'll see them. You'll also see the in car temp sensor when you remove the vent cover.Are you sure the AC system is charged correctly and have you removed the blower control module in the evaporator housing and looked at the temp door while someone else operates the controls to see if the door is going from max heat to max cold?
Any advice as to where to obtain a new temp door motor???
Thanks
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
http://www.ecklers.com/air-condition...d-heating.html
They call it a temperature valve actuator-but it looks like what you need. 
You might give them a call to verify.
Just thought about this---FYI when you get the temp motor from where ever it's available--install it in place-disconnect battery for a bit--reconnect and system should "learn" its new limits. I mention this because the motor/potentiometer will be damaged with out the blend door to stop it at max hot and cold. Do not hook up the connector and watch the motor turn in your hand --damage can occur-just a heads up.
They call it a temperature valve actuator
-but it looks like what you need. You might give them a call to verify.Just thought about this---FYI when you get the temp motor from where ever it's available--install it in place-disconnect battery for a bit--reconnect and system should "learn" its new limits. I mention this because the motor/potentiometer will be damaged with out the blend door to stop it at max hot and cold. Do not hook up the connector and watch the motor turn in your hand --damage can occur-just a heads up.
Last edited by TWISTERUP; Jun 7, 2011 at 05:12 PM.
Melting Slicks
Joined: Jul 2008
Posts: 2,269
Likes: 142
From: Ottawa Ontario
http://www.ecklers.com/air-condition...d-heating.html
They call it a temperature valve actuator-but it looks like what you need. You might give them a call to verify.
They call it a temperature valve actuator
-but it looks like what you need. You might give them a call to verify.
Heel & Toe
Joined: Apr 2011
Posts: 16
Likes: 0
Before you put an actuator in it you need to check the voltage going to it from the hvac programmer. The hvac programmer changes the ground and power feeds back and forth to move the door as needed. The connector going to the temp door actuator the wires to check should be dark blue and the other yellow. With a voltage meter command the temp to 90 degrees and you should see a voltage of like positive 8 or more. Then switch to 60 degrees; as you get the outside temp the voltage should change to 0; and when you get to 60 it should reverse to negative 8 or more. If it just stays zero then the programmer is not reversing polarity to moving the door cold. Now if you hook up to the wires and it starts out reading negative and then goes to positive as you change the temps that is the same thing it is just how your meter is connected. What I am trying to emphasize is that there should be a voltage reversal when you go from extreme hot to extreme cold. If it does this then you need actuator if it doesn't you need a hvac programmer most likely.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
Before you put an actuator in it you need to check the voltage going to it from the hvac programmer. The hvac programmer changes the ground and power feeds back and forth to move the door as needed. The connector going to the temp door actuator the wires to check should be dark blue and the other yellow. With a voltage meter command the temp to 90 degrees and you should see a voltage of like positive 8 or more. Then switch to 60 degrees; as you get the outside temp the voltage should change to 0; and when you get to 60 it should reverse to negative 8 or more. If it just stays zero then the programmer is not reversing polarity to moving the door cold. Now if you hook up to the wires and it starts out reading negative and then goes to positive as you change the temps that is the same thing it is just how your meter is connected. What I am trying to emphasize is that there should be a voltage reversal when you go from extreme hot to extreme cold. If it does this then you need actuator if it doesn't you need a hvac programmer most likely.
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Had this problem as well...turned out to be a cold solder joint on the temp door motor. Just remove the motor housing and open it up....your could be as simple as mine was.
Apply 12 volts across the motor terminals to check motor operation. The motor looks like one from an old slot car.
See picture:
Apply 12 volts across the motor terminals to check motor operation. The motor looks like one from an old slot car.
See picture:
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
Thank's everyone for the help. I got the motor from Ecklers and had to grind it to fit as the last post suggested. While I had it apart I replaced the flasher with an electronic one in case I decide on LED tail lights. A/C is cold and works properly.
Burning Brakes
Joined: Nov 2009
Posts: 828
Likes: 103
From: Olney MD
Can you see the actuator from underneath?
(any pix?)
Thanks!
Paul
Thread Starter
Instructor
Joined: Oct 2008
Posts: 109
Likes: 7
From: Monterey Ca
I think you can see it. I have a 95 and I could see mine. it is very close to the floor board. I used a multi meter and allegator clips on the incoming wires to see if I had the proper signal first.
Once I proved the signal was correct I was pretty sure it was the motor.
Once I proved the signal was correct I was pretty sure it was the motor.
Burning Brakes
Joined: Nov 2009
Posts: 828
Likes: 103
From: Olney MD
Upside down on the passenger side!
I think you can see it. I have a 95 and I could see mine. it is very close to the floor board. I used a multi meter and allegator clips on the incoming wires to see if I had the proper signal first.
Once I proved the signal was correct I was pretty sure it was the motor.
Once I proved the signal was correct I was pretty sure it was the motor.
My son who is home from college will be the victim. I just want to assure him that he will be able to see it. I bought a blend door motor ages ago, so I won't bother with the voltmeter. If the problem turns out to be the controller (with all the vacuum hoses), I'll draft him for duty the following weekend. The bribe is that I'll let him drive the Vette once it's fixed!
Stay tuned!
Paul
1st Gear
Joined: Jan 2012
Posts: 1
Likes: 0
Need some heat in January
I have the 96 with auto climate control, I appreciate the tips below and have been following them closely. when set at 60 degrees the blower will kick on full and blow cold A/C, anything above 60 and I get the flashing light on the conroller and the blower motor shuts down. when I look in at the door, on 60 degrees it travels all the way over and seals, once temp increase is requested the door travels about half way over and waffles, there is the slight clicking noise and buzz. I tried the reset with the fuses out with the ingnition in the on position, I have also disconnected the ground and waited. same same when I connect it back up. Do these change the diagnose of blend door motor? any help is appreciated on my budget!!
Heel & Toe
Joined: Apr 2011
Posts: 16
Likes: 0
I have the 96 with auto climate control, I appreciate the tips below and have been following them closely. when set at 60 degrees the blower will kick on full and blow cold A/C, anything above 60 and I get the flashing light on the conroller and the blower motor shuts down. when I look in at the door, on 60 degrees it travels all the way over and seals, once temp increase is requested the door travels about half way over and waffles, there is the slight clicking noise and buzz. I tried the reset with the fuses out with the ingnition in the on position, I have also disconnected the ground and waited. same same when I connect it back up. Do these change the diagnose of blend door motor? any help is appreciated on my budget!!