C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

AC heater control valve or ?? help

Thread Tools
 
Search this Thread
 
Old May 16, 2016 | 01:05 AM
  #21  
Cliff Harris's Avatar
Cliff Harris
Race Director
15 Year Member
 
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Default

You can see the blend door motor from the bottom. I don't remember what you need to remove to see it.
Reply
Old May 16, 2016 | 03:18 AM
  #22  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

Thanks Cliff
I'll take a look from below first.
From the pic I found though it looks like the motor is behind the ECM but I have never seen it myself so can't say for sure.


Originally Posted by Cliff Harris
You can see the blend door motor from the bottom. I don't remember what you need to remove to see it.
Reply
Old May 16, 2016 | 08:14 PM
  #23  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

I'm have trouble loading pics so most have no names. 3 pics are of the programmer and the other is the blend door motor mounted to the heater core assembly. I own a spare assembly.
This is my version of removing the AC programmer.

If you are of medium build then put the driver seat all the way back.
Remove the seat cushion. If the seat is still in your way, pull it out.
Take the driver hush panel out.
The area you need to reach is above the gas pedal and very near the black floor duct.
The programmer is held on by one 7mm screw a the bottom. Look at the tab on the programmer shown. That end is on the bottom.
You do just about all the work with your right hand.
You will need a 1/4 ratchet, very long extension, 7mm socket.
Remove that 7mm screw and the pull down on the programmer to free it from the top mounting tabs. The black floor duct might give you trouble.
Pull the electrical plug off and pull the programmer down as far as you can.
You will have to "deal" with all the silicone tubes as they are. There is a long but skinny bolt that holds the silicone tubes to the inside of the programmer (see pic which shows the electronics).
GM recessed the bolt head so it is impossible to use a socket so you will need pliers like shown. There is a press nut that holds the silicone block to the box. Take the pliers, find the press nut and twist it until it breaks. Don't get too aggressive as to not put a hole in a tube. The nut is very thin and will break. This is the hardest part.
Once the nut is off take a screw driver and prize the silicone block off.
The programmer is now free.

That press nut you destroyed will be replaced with a nut that fits a 1/4 socket and using a short extension and your hand (not the ratchet) to re-attach the silicone block onto the programmer.

I did not have to lay upside down to remove or re-install the programmer.

If you need tips to remove the blend door motor (and I hope you don't) I have some tips on that also.
Attached Images     

Last edited by HAD2HAV2; May 16, 2016 at 08:18 PM.
Reply
Old May 16, 2016 | 09:15 PM
  #24  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

HAD2HAVE2
thanks for all the information, I am grateful.
I removed the blower control and could see the door and could move it freely.

With the passenger side hush panel removed and the ignition in the on position, I could up the temperature and hear a sound like an actuator but the door did not move.

So I reckoned the rod or the bushing is bad.

I took the dash pad off today and some trim that was required.
What is located behind the bread box is over my head.
I could only undo 2 of the 4 bolts that hold the bread box. The other two on the bottom were on backwards meaning I could see the tip of the screw and not the head...who does this ??!!

There was supports and duct work and a bunch of wires between me and the ECM. Based on the location of the door from the engine compartment I can say the actuator is behind the ECM and getting to it is beyond my ability right now.

I'm going to have to bypass the heater core to restore AC while I decide what to do. Pretty pissed because stuff like this drives me NUTS.

So yes if you have any tips on getting to this actuator I would appreciate them.

The good news is though that based on what I saw it's not a head unit or controller issue.


I will try post some pics in a while.

Thanks again to all who helped. I am starting to like this place.


Originally Posted by HAD2HAV2
I'm have trouble loading pics so most have no names. 3 pics are of the programmer and the other is the blend door motor mounted to the heater core assembly. I own a spare assembly.
This is my version of removing the AC programmer.

If you are of medium build then put the driver seat all the way back.
Remove the seat cushion. If the seat is still in your way, pull it out.
Take the driver hush panel out.
The area you need to reach is above the gas pedal and very near the black floor duct.
The programmer is held on by one 7mm screw a the bottom. Look at the tab on the programmer shown. That end is on the bottom.
You do just about all the work with your right hand.
You will need a 1/4 ratchet, very long extension, 7mm socket.
Remove that 7mm screw and the pull down on the programmer to free it from the top mounting tabs. The black floor duct might give you trouble.
Pull the electrical plug off and pull the programmer down as far as you can.
You will have to "deal" with all the silicone tubes as they are. There is a long but skinny bolt that holds the silicone tubes to the inside of the programmer (see pic which shows the electronics).
GM recessed the bolt head so it is impossible to use a socket so you will need pliers like shown. There is a press nut that holds the silicone block to the box. Take the pliers, find the press nut and twist it until it breaks. Don't get too aggressive as to not put a hole in a tube. The nut is very thin and will break. This is the hardest part.
Once the nut is off take a screw driver and prize the silicone block off.
The programmer is now free.

That press nut you destroyed will be replaced with a nut that fits a 1/4 socket and using a short extension and your hand (not the ratchet) to re-attach the silicone block onto the programmer.

I did not have to lay upside down to remove or re-install the programmer.

If you need tips to remove the blend door motor (and I hope you don't) I have some tips on that also.

Last edited by Big Bird 88; May 16, 2016 at 09:19 PM.
Reply
Old May 16, 2016 | 09:29 PM
  #25  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

Originally Posted by Big Bird 88
HAD2HAVE2
thanks for all the information, I am grateful.
I removed the blower control and could see the door and could move it freely.

With the passenger side hush panel removed and the ignition in the on position, I could up the temperature and hear a sound like an actuator but the door did not move.

So I reckoned the rod or the bushing is bad.

I took the dash pad off today and some trim that was required.
What is located behind the bread box is over my head.
I could only undo 2 of the 4 bolts that hold the bread box. The other two on the bottom were on backwards meaning I could see the tip of the screw and not the head...who does this ??!!

There was supports and duct work and a bunch of wires between me and the ECM. Based on the location of the door from the engine compartment I can say the actuator is behind the ECM and getting to it is beyond my ability right now.

I'm going to have to bypass the heater core to restore AC while I decide what to do. Pretty pissed because stuff like this drives me NUTS.

So yes if you have any tips on getting to this actuator I would appreciate them.

The good news is though that based on what I saw it's not a head unit or controller issue.


I will try post some pics in a while.

Thanks again to all who helped. I am starting to like this place.
Pic of the door visible through the Blower




Blend Door



Pic of what I found when I took of the dash pad and was in the process of removing the bread box. Sorry fro the reflection :-)




behind the breadbox

I could not get the bottom two screws off for the bread box, but based on the metal cross beam, with attached electronics, box duct bolted to the cross beam and then the ECM all of which would need to be removed to get to this actuator, I felt I was over my head so backed out and reassembled.

About 3 hours from start to finish.
Reply
Old May 16, 2016 | 09:35 PM
  #26  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

It seems the little white clip that attaches the blend door rod to the motor is broken. I removed my bread box years ago and replaced it with an after market panel with a cloth pouch.
To get to the motor:
You are part of the way there already.
Drop the passenger hush panel.
You need to lower the ECM by removing 2 -10mm bolts.
You can see a lot with the breadbox removed.
Remove the ECM case, 4 screws.
Motor is held on by 2- 7mm screws if you need to remove it.
Some have replaced this discontinued clip with a plastic door latch clip. I tried that but saw the rod slip in the clip when the rod/mover lever was going from on end to the other by adjusting the temp from 60 to 90. I used a metal nut (that I can attach to the rod) welded to a bolt stud that slips inside the hole of the doo motor lever.



replaced the plastic clip with a nut/bolt stud welded together.
Keep us informed Big Bird.
Reply
Old May 16, 2016 | 09:44 PM
  #27  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

Originally Posted by Big Bird 88
Pic of the door visible through the Blower




Blend Door



Pic of what I found when I took of the dash pad and was in the process of removing the bread box. Sorry fro the reflection :-)




behind the breadbox

I could not get the bottom two screws off for the bread box, but based on the metal cross beam, with attached electronics, box duct bolted to the cross beam and then the ECM all of which would need to be removed to get to this actuator, I felt I was over my head so backed out and reassembled.

About 3 hours from start to finish.
Been a log time (the 90's), I cut those 2 pesky screws to get the bread box off but I was replacing the box. Box needs to go so you can see what you will be doing while sitting in the seat or you will have to lie on you back and work from the underneath side.
Reply
Old May 16, 2016 | 09:52 PM
  #28  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

Well at 6-2 and 210 I guess I am pulling the passenger seat.
I kinds like the bread box. I will look on Ebay for brackets so I can replace them if I cut two.

So is that actuator basically behind the ECM ? When I drop the ECM from below, then I will be able to see the Actuator ?

I like the fitting you put together..
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old May 16, 2016 | 09:58 PM
  #29  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

Originally Posted by Big Bird 88
Well at 6-2 and 210 I guess I am pulling the passenger seat.
I kinds like the bread box. I will look on Ebay for brackets so I can replace them if I cut two.

So is that actuator basically behind the ECM ? When I drop the ECM from below, then I will be able to see the Actuator ?

I like the fitting you put together..
The ECM and its box mount are in the way of you looking down from looking from the seat and seeing the clip and motor.
Reply
Old May 17, 2016 | 03:53 AM
  #30  
Cliff Harris's Avatar
Cliff Harris
Race Director
15 Year Member
 
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Default

Originally Posted by Big Bird 88
HAD2HAVE2
thanks for all the information, I am grateful.
I removed the blower control and could see the door and could move it freely.
You shouldn't be able to move it. It's solidly linked to the blend door motor. It sounds like something is broken or disconnected.
Reply
Old May 17, 2016 | 09:05 AM
  #31  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

Big Bird, I can give you a temporary fix but you will need a volunteer. Find someone that can fit their hand down the BCM hole, my wife did. Give them a thick sock (athletic type) and have them slide the sock under the blend door and they can push the door almost closed or use a long breaker bar. I had my wife do the exact fix until I got my homemade metal clip welded together. This should give you around 68F to keep you cool until September when you can get the bread box off or go underneath when you have extra time. Stay cool my friend. PM me if you want info on that metal clip I had made. I have an extra one.
Reply
Old May 17, 2016 | 09:06 AM
  #32  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

Originally Posted by Cliff Harris
You shouldn't be able to move it. It's solidly linked to the blend door motor. It sounds like something is broken or disconnected.
Cliff,
Not of the plastic clip is broken on the blend door motor.
Reply
Old May 17, 2016 | 09:07 AM
  #33  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

Big Bird, I forgot something. Is the metal rod still connected to the blend door?

Last edited by HAD2HAV2; May 17, 2016 at 09:09 AM.
Reply
Old May 17, 2016 | 10:36 AM
  #34  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

Originally Posted by HAD2HAV2
Big Bird, I can give you a temporary fix but you will need a volunteer. Find someone that can fit their hand down the BCM hole, my wife did. Give them a thick sock (athletic type) and have them slide the sock under the blend door and they can push the door almost closed or use a long breaker bar. I had my wife do the exact fix until I got my homemade metal clip welded together. This should give you around 68F to keep you cool until September when you can get the bread box off or go underneath when you have extra time. Stay cool my friend. PM me if you want info on that metal clip I had made. I have an extra one.
HAD2HAVE2

Thanks, I was thinking about that and wondering if taping the door would work. When I look in the BCM hole I would need to tape the door to the left ? ??

I will probably do that today.

I am doing a coolant flush, diff fluid and cat back this weekend with a friend who has a lift. When I flush the coolant I am going to put in a manual heater core bypass which will also help.

I am trying to track down the bushings, I am hoping that is it as I have not been able to see the actuator.

Once I get the pars I will try again.
Both you and Cliff have been a big help as this is all new to me.

I will PM you later.

Thanks

Big Bird
Reply
Old May 17, 2016 | 11:04 AM
  #35  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

[QUOTE=Big Bird 88;1592232095]HAD2HAVE2

Thanks, I was thinking about that and wondering if taping the door would work. When I look in the BCM hole I would need to tape the door to the left ? ??


Correct. You want to cover up the part that looks like a mini radiator (that's the heater core) and that would be on the left side as you look down.
Reply
Old May 17, 2016 | 12:51 PM
  #36  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

[QUOTE=HAD2HAV2;1592232337]
Originally Posted by Big Bird 88
HAD2HAVE2

Thanks, I was thinking about that and wondering if taping the door would work. When I look in the BCM hole I would need to tape the door to the left ? ??


Correct. You want to cover up the part that looks like a mini radiator (that's the heater core) and that would be on the left side as you look down.
Well when my daughter comes home from school guess what she will be doing ;-)
Reply
Old May 18, 2016 | 01:27 AM
  #37  
Cliff Harris's Avatar
Cliff Harris
Race Director
15 Year Member
 
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Default

Originally Posted by HAD2HAV2
Cliff,
Not of the plastic clip is broken on the blend door motor.
I think you meant "not IF the plastic clip...", which is exactly what I said.

If you can move it something is broken.
Reply

Get notified of new replies

To AC heater control valve or ?? help

Old May 18, 2016 | 08:56 AM
  #38  
HAD2HAV2's Avatar
HAD2HAV2
Melting Slicks
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Default

Originally Posted by Cliff Harris
I think you meant "not IF the plastic clip...", which is exactly what I said.

If you can move it something is broken.
My bad. I was tired from typing and trying to remember what I had to do 2 years ago when you helped me with the same problem.

Last edited by HAD2HAV2; May 18, 2016 at 08:58 AM.
Reply
Old May 25, 2016 | 02:09 PM
  #39  
Big Bird 88's Avatar
Big Bird 88
Thread Starter
Instructor
 
Joined: Apr 2016
Posts: 163
Likes: 4
Default

Well I was able to track down the part. It cost me $15 plus shipping, which I guess is OK.
My AC fix with the tape is holding so I'm thinking if I can get through the summer, I will spend the 4 or so hours taking the dash apart to put the little clip in.

Thanks everyone for the help. On to the next project.
Reply
Old May 26, 2016 | 07:46 AM
  #40  
bad-zr1's Avatar
bad-zr1
Racer
20 Year Member
All Eyes On Me
 
Joined: Oct 2002
Posts: 372
Likes: 1
From: Corunna Mi
Default

Where were you able to find the plastic piece? I need one also.
Thanks
Reply



All times are GMT -4. The time now is 01:12 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE