C5 Climate Control dim/dark display fix
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The passegers adjustment **** will only change the passengers vent temp +- 10% of what the driver side is set to.
Use the DIC and read the DTCs and you will see if there are any HVAC errors/issues.
GM did that way to prevent thunder and lightening storms happening between the drivers side and the passengers side when the Wife/Girl Friend wants it set to 90 deg on her side and you want it set to 60 deg on your side.........
Navigator
Joined: Jul 2011
Posts: 9
Likes: 0
I agree!
The passegers adjustment **** will only change the passengers vent temp +- 10% of what the driver side is set to.
Use the DIC and read the DTCs and you will see if there are any HVAC errors/issues.
GM did that way to prevent thunder and lightening storms happening between the drivers side and the passengers side when the Wife/Girl Friend wants it set to 90 deg on her side and you want it set to 60 deg on your side.........
The passegers adjustment **** will only change the passengers vent temp +- 10% of what the driver side is set to.
Use the DIC and read the DTCs and you will see if there are any HVAC errors/issues.
GM did that way to prevent thunder and lightening storms happening between the drivers side and the passengers side when the Wife/Girl Friend wants it set to 90 deg on her side and you want it set to 60 deg on your side.........
6th Gear
Joined: Apr 2014
Posts: 6
Likes: 0
From: Channel Islands California
Thanks for the post, the longest time was figuring out how to unplug some of the wiring. When done if worked great. Lasted about 6 months then had to do it again. Also remember not to grab the soldering iron with you fingers if you drop it, just let it fall. This will leave a mark.
Instructor
Joined: Sep 2006
Posts: 134
Likes: 2
From: Bloomington Illinois
Dim HVAC and Navy service
Anyway, as spring is approaching it's time to "do the repair" again. One thing I noticed today is a comment about applying the soldering iron to "both" sides of the board. I'm sure I only applied heat and a little solder to the top side of the board. I intend to touch up both sides this time but would appreciate any additional guidance. I do have a "cold" battery powered soldering iron. THANKS!!
1st Gear
Joined: Feb 2005
Posts: 1
Likes: 0
From: Hillsboro OR
A few tips to add to this great fix
I just had this problem occur on my 2001 which had the newer style board on it. I reheated the eight 240 ohm resistors and the display is now bright as new. As an electronics guy, here are a few tips I can add to this great fix...
I can't speak to the way the older board is configured, but on the newer board I know that the 240 ohm resistors are in parallel. If they are all soldered down correctly, the resistance across any one of the eight resistors should read approximately 30 ohms (240/8 = 30). If you get a significantly higher reading, one or more of the resistors needs solder re-flow.
To aid in solder re-flow, apply a small amount of water soluble flux to the ends of all the resistors. This will help to transfer the heat from the soldering iron to the joint and aids in the metal bonding as the flux prevents oxides from forming during the heating process. A flux pen is a convenient way to apply it. Do a search for "flux pen" to find one for sale online. Surface mount devices are much easier to solder with the right flux as part of the process. After you are finished, you can clean the excess flux off the board with alcohol or acetone. Cotton swabs can be used to apply the solvent.
While the resistors are not electrostatic sensitive, there are many components on the board that are. To prevent damage to the electronics while handling the circuit board, observe ESD precautions. If you don't know what that implies, just do a search for it. If you live in a dry climate, be extra careful about ESD. It would suck to fix the display problem only to zap the microprocessor in the process.
I can't speak to the way the older board is configured, but on the newer board I know that the 240 ohm resistors are in parallel. If they are all soldered down correctly, the resistance across any one of the eight resistors should read approximately 30 ohms (240/8 = 30). If you get a significantly higher reading, one or more of the resistors needs solder re-flow.
To aid in solder re-flow, apply a small amount of water soluble flux to the ends of all the resistors. This will help to transfer the heat from the soldering iron to the joint and aids in the metal bonding as the flux prevents oxides from forming during the heating process. A flux pen is a convenient way to apply it. Do a search for "flux pen" to find one for sale online. Surface mount devices are much easier to solder with the right flux as part of the process. After you are finished, you can clean the excess flux off the board with alcohol or acetone. Cotton swabs can be used to apply the solvent.
While the resistors are not electrostatic sensitive, there are many components on the board that are. To prevent damage to the electronics while handling the circuit board, observe ESD precautions. If you don't know what that implies, just do a search for it. If you live in a dry climate, be extra careful about ESD. It would suck to fix the display problem only to zap the microprocessor in the process.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
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Racer
Joined: May 2013
Posts: 371
Likes: 20
From: Ft. Collins Colorado
First and foremost, this is not my fix! I spent a while searching multiple forums on info on how to do this, and found it all in several places. All I'm doing is collecting the info I found to put it in one step by step place with minor footnotes of my own. I will list names and URL's to each area I found the info from, and if anyone would like their info removed I will gladly do so!
Just trying to save the next poor guy some time for looking all over and following all the various links from everywhere
Hope this helps!
For the first steps, find pictures and more detailed instructions where I did, at http://www.vetteessentials.com/instr...zel_howto.html
Their list of tools is for a bigger job, you wont need all of the ones listed, you'll need others for actually fixing the control unit, and you only need to go to step 3g, no further for this section!
***If you have a convertible with the body colored "waterfall" you will have to remove it first. If not, skip this step. 4 screws total, size 15 torx screws, two on the top, one on each side towards the bottom. Just gently pull up to remove it.
Remove the console - Gently remove the Active Handling trim plate and wiring connections beneath it and to the console. Remove the 4 10mm nuts. Pick up only the back of the console to get it over the rear bolts, then slide it towards the back to get it out from the front bolts. The front is slotted to slide all the way out.
Remove the instrument trim panel - Gently pry out the trim panel to the left of the ignition switch, and remove the ashtray. Remove the 3 #15 torx screws. GENTLY pull the panel only a little ways! Back towards the top, and up at the bottom/back where 2 of the 10mm nuts were removed from the front of the console area (behind the shifter). Remove the cigarette lighter power. ***If it's a 6spd, remove the boot carefully, I pulled mine up, but this site says you can push it down also*** Once you've verified everything is free, carefully pull it out and set it safely aside.
Again, I highly recommend going to the following site http://www.vetteessentials.com/instr...zel_howto.html for pictures and a more detailed step by step instructions for the above steps.
The following steps are not found at the above URL.
Now you have a clear shot to your Climate Control unit! There are only 2 screws holding it in place. I'm sorry I didn’t get the size of them, but they're easily accessible to test a few sockets to find the perfect match
Remove the screws, pull the unit out a little way, and remove the connector in the back. Pay attention to the connector, there's an area you have to press to release the clip to be able to pull it out.
Now that you have the unit out, take it to a safe place, preferably the clean worktable you will be finishing the work on it
Carefully remove the 4 screws on the corners holding it together. They are small, and have very coarse threads, so use a hand screwdriver style tool preferably, NOT a drill, if you only have a ratchet set, just be very careful not to over tighten it when you're done!
The following was ninja'ed from RPOZ4Z at Corvette Forum http://forums.corvetteforum.com/show...1316227&page=2 on page 2 post # 24. Thank you VERY much RPOZ4Z for putting words to sight so I knew what the hell to solder!!!
There is a 2nd variation of this board, which is the one I found in my 01 convertible. Thank you EnglandGreen for posting the other kind of board as seen below! http://forums.corvetteforum.com/show...1316227&page=3 Same thread, page 3 post #50
On both boards, it's very easy to unplug the power board from the front of the unit to work on it. And on either board, what you're looking for is those little black guys with "241" printed on them. I used a Cold Heat soldering gun I got from Radio shack an hour or two earlier in my then together car The tip it came with was not ideal, but it finally got the job done!
I tried to see which seemed loose and only solder those few. Don’t bother trying, either you wont be able to tell, or you'll break them off looking for the loose ones. I fixed the 2 obvious ones, and went out to the car to try it, but only got a very dim light. When I went back and soldered more they were practically ALL broken on one side
Be careful to try and hold them in place so they don’t move if you happen to solder the good end first. I had one come completely off the board, and it was very hard to get it back on. I eventually wound up putting solder on the contacts on the board first, then putting the chip back on and soldering, it was a pain. I just rested the back of a tiny jeweler’s screwdriver on them to keep them in place, it doesn’t take much.
When you finally have them all done on both sides, carefully put the unit back together. Be sure to line up the pins on the back cover, and be careful with the small coarse threaded screws. I put them in the hole, turned them backwards until I felt where the thread was and then gently screwed them in until tight. You do not want to torque them at all, it will be obvious when they're tight and you're against the circuit board. Same with the screws that hold the casing together.
Now before you put everything back together in your car, make sure you turn the ignition on to make sure it lights up! You don’t need to start the car, just put it in the on position. Assuming everything works, CONGRATULATIONS! Follow the steps in reverse order to put everything back together, reconnect all the electrical items, and make sure not to strip or over tighten anything. One thing I did notice is the screw behind the ashtray seems loose when you're putting it back together at first. It's just the nature of the clip. Once the dash is in position and you snug it up it will get tight.
Now that I know what I'm doing, it really is a quick job! If you read up and study the pictures first, it should go pretty smoothly long as you or someone you know can solder ok
Cordless Coldheat Soldering gun - $19.99
4 pack AA batteries - $3.99
.022 dia High Tech Rosin Core Solder - $3.99
Saving $500 and a day spent at the dealership with no car - priceless!
-ALSO!!! If you DONT want to risk soldering it yourself, try a local reputable electronics expert. Long as you can show him what's broke he can probably fix it. Or if you have time to wait for mail have an expert do it for you!!! I don’t know this person at all, I just found the following in my search!
From member rws.1 http://forums.corvetteforum.com/show...t=David+Ruberg post #2
and from member widewheel http://forums.corvetteforum.com/show...t=David+Ruberg post #3
I personally needed the soldering equipment to fix a headset as well, and plan to use it in the future so for me it was worth it. But if you're concerned, don’t have the equipment, $45-$50 to have someone do it and warranty it vs. $28 in equipment sounds like a pretty darn good deal!!! Looks like he gets rave reviews to boot!
MUCH thanks to everyone that did the legwork everywhere to get all this great info out there, I hope this makes it easier to find and read through all the various steps!
Just trying to save the next poor guy some time for looking all over and following all the various links from everywhere
Hope this helps!
For the first steps, find pictures and more detailed instructions where I did, at http://www.vetteessentials.com/instr...zel_howto.html
Their list of tools is for a bigger job, you wont need all of the ones listed, you'll need others for actually fixing the control unit, and you only need to go to step 3g, no further for this section!
***If you have a convertible with the body colored "waterfall" you will have to remove it first. If not, skip this step. 4 screws total, size 15 torx screws, two on the top, one on each side towards the bottom. Just gently pull up to remove it.
Remove the console - Gently remove the Active Handling trim plate and wiring connections beneath it and to the console. Remove the 4 10mm nuts. Pick up only the back of the console to get it over the rear bolts, then slide it towards the back to get it out from the front bolts. The front is slotted to slide all the way out.
Remove the instrument trim panel - Gently pry out the trim panel to the left of the ignition switch, and remove the ashtray. Remove the 3 #15 torx screws. GENTLY pull the panel only a little ways! Back towards the top, and up at the bottom/back where 2 of the 10mm nuts were removed from the front of the console area (behind the shifter). Remove the cigarette lighter power. ***If it's a 6spd, remove the boot carefully, I pulled mine up, but this site says you can push it down also*** Once you've verified everything is free, carefully pull it out and set it safely aside.
Again, I highly recommend going to the following site http://www.vetteessentials.com/instr...zel_howto.html for pictures and a more detailed step by step instructions for the above steps.
The following steps are not found at the above URL.
Now you have a clear shot to your Climate Control unit! There are only 2 screws holding it in place. I'm sorry I didn’t get the size of them, but they're easily accessible to test a few sockets to find the perfect match
Remove the screws, pull the unit out a little way, and remove the connector in the back. Pay attention to the connector, there's an area you have to press to release the clip to be able to pull it out.Now that you have the unit out, take it to a safe place, preferably the clean worktable you will be finishing the work on it
Carefully remove the 4 screws on the corners holding it together. They are small, and have very coarse threads, so use a hand screwdriver style tool preferably, NOT a drill, if you only have a ratchet set, just be very careful not to over tighten it when you're done!
The following was ninja'ed from RPOZ4Z at Corvette Forum http://forums.corvetteforum.com/show...1316227&page=2 on page 2 post # 24. Thank you VERY much RPOZ4Z for putting words to sight so I knew what the hell to solder!!!
There is a 2nd variation of this board, which is the one I found in my 01 convertible. Thank you EnglandGreen for posting the other kind of board as seen below! http://forums.corvetteforum.com/show...1316227&page=3 Same thread, page 3 post #50
On both boards, it's very easy to unplug the power board from the front of the unit to work on it. And on either board, what you're looking for is those little black guys with "241" printed on them. I used a Cold Heat soldering gun I got from Radio shack an hour or two earlier in my then together car
The tip it came with was not ideal, but it finally got the job done!I tried to see which seemed loose and only solder those few. Don’t bother trying, either you wont be able to tell, or you'll break them off looking for the loose ones. I fixed the 2 obvious ones, and went out to the car to try it, but only got a very dim light. When I went back and soldered more they were practically ALL broken on one side
Be careful to try and hold them in place so they don’t move if you happen to solder the good end first. I had one come completely off the board, and it was very hard to get it back on. I eventually wound up putting solder on the contacts on the board first, then putting the chip back on and soldering, it was a pain. I just rested the back of a tiny jeweler’s screwdriver on them to keep them in place, it doesn’t take much.
When you finally have them all done on both sides, carefully put the unit back together. Be sure to line up the pins on the back cover, and be careful with the small coarse threaded screws. I put them in the hole, turned them backwards until I felt where the thread was and then gently screwed them in until tight. You do not want to torque them at all, it will be obvious when they're tight and you're against the circuit board. Same with the screws that hold the casing together.
Now before you put everything back together in your car, make sure you turn the ignition on to make sure it lights up! You don’t need to start the car, just put it in the on position. Assuming everything works, CONGRATULATIONS! Follow the steps in reverse order to put everything back together, reconnect all the electrical items, and make sure not to strip or over tighten anything. One thing I did notice is the screw behind the ashtray seems loose when you're putting it back together at first. It's just the nature of the clip. Once the dash is in position and you snug it up it will get tight.
Now that I know what I'm doing, it really is a quick job! If you read up and study the pictures first, it should go pretty smoothly long as you or someone you know can solder ok
Cordless Coldheat Soldering gun - $19.99
4 pack AA batteries - $3.99
.022 dia High Tech Rosin Core Solder - $3.99
Saving $500 and a day spent at the dealership with no car - priceless!
-ALSO!!! If you DONT want to risk soldering it yourself, try a local reputable electronics expert. Long as you can show him what's broke he can probably fix it. Or if you have time to wait for mail have an expert do it for you!!! I don’t know this person at all, I just found the following in my search!
From member rws.1 http://forums.corvetteforum.com/show...t=David+Ruberg post #2
and from member widewheel http://forums.corvetteforum.com/show...t=David+Ruberg post #3
I personally needed the soldering equipment to fix a headset as well, and plan to use it in the future so for me it was worth it. But if you're concerned, don’t have the equipment, $45-$50 to have someone do it and warranty it vs. $28 in equipment sounds like a pretty darn good deal!!! Looks like he gets rave reviews to boot!
MUCH thanks to everyone that did the legwork everywhere to get all this great info out there, I hope this makes it easier to find and read through all the various steps!
Drifting
Joined: Mar 2010
Posts: 1,628
Likes: 15
From: Seattle WA
I just did this one last week, for the second time. First time evidently I wasn't good enough...
When I was testing it after the first hit of solder, I noticed that these little 0603 size resistors (1/16 watt rated) get awfully hot during operation, which could certainly be a factor in why they seem to come undone.
I dropped one of the little guys when I was resoldering after testing and the resistor went flying to who knows where. I ended up cannibalizing electronics until I found a 1/2 watt resistor at 238 ohms, close enough to 241, and soldered that in place. Display works like a charm!
So, if you lose one of the resistors, don't fret; you can just get a standard 1/4 or 1/2 watt resistor to take its place and you'll be fine.
I wonder if replacing all of them with a single 5 watt 30 ohm resistor would be best?
When I was testing it after the first hit of solder, I noticed that these little 0603 size resistors (1/16 watt rated) get awfully hot during operation, which could certainly be a factor in why they seem to come undone.
I dropped one of the little guys when I was resoldering after testing and the resistor went flying to who knows where. I ended up cannibalizing electronics until I found a 1/2 watt resistor at 238 ohms, close enough to 241, and soldered that in place. Display works like a charm!
So, if you lose one of the resistors, don't fret; you can just get a standard 1/4 or 1/2 watt resistor to take its place and you'll be fine.
I wonder if replacing all of them with a single 5 watt 30 ohm resistor would be best?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If you have no EBTCM messages or DTCs, TAC DTCs or PCM DTCs, it has to be the switches (brake, clutch or multifunction. Short of actually measuring continuity, there not much else to do.
You can have the system checked with a TECH2 and that alone will allow you to see the state of all the switch, watch them change state and see if the the TAC is getting the cruise signal.
Actually use a DC Voltmeter and see if you have full battery voltage on each test point on top of the fuses to chassis ground.
Bill
You can have the system checked with a TECH2 and that alone will allow you to see the state of all the switch, watch them change state and see if the the TAC is getting the cruise signal.
Actually use a DC Voltmeter and see if you have full battery voltage on each test point on top of the fuses to chassis ground.
Bill
Drifting
Joined: Jan 2014
Posts: 1,568
Likes: 594
From: Jefferson City Missouri
Thanks for the instructions OP!!!!
A friend of mine has an 03 convertible and we did the repair this morning. It works perfect. I did find one of the resistors was loose on one side. He has the second board with the eight 241's in two parallel rows. Easy job. Finished up and sat down to drink some wine with our wives.
A friend of mine has an 03 convertible and we did the repair this morning. It works perfect. I did find one of the resistors was loose on one side. He has the second board with the eight 241's in two parallel rows. Easy job. Finished up and sat down to drink some wine with our wives.
Intermediate
Joined: Oct 2012
Posts: 25
Likes: 0
From: Lebanon TN
A related but totally different problem - solved finally
My climate control unit would go dead. Intermittent at first. Eventually it would come back. Finally it never came back. When dead, you can't turn on the fan, switch modes, change temps, nothing.
(side note - some while later, not sure how much later, I got a check engine light - the code was for bad oxygen sensor heaters - in all four oxygen sensors at once)
After finally digging into it (this happened over a year ago) and digging through the manual, looking up schematics, pinouts, power and ground circuits, etc. I finally figured it out. There are only two things that run off the "on" side of the switch. Everything else runs off "acc/on" or "run/start".
Guess what the two things are.... Climate control and oxygen sensor heaters.
Backtracking through the wiring, found the problem was in the ignition switch contacts. I was getting 0.2 volts on the yellow wire. Disassembled the ignition switch, filed the contacts, and everything started working again.
p.s. This was only after sending the unit off for repair, and still had the same problem when it came back. Then I knew I had to dig into the wiring. The 12v batt pin was hot, but the 12v switched pin was not.
(side note - some while later, not sure how much later, I got a check engine light - the code was for bad oxygen sensor heaters - in all four oxygen sensors at once)
After finally digging into it (this happened over a year ago) and digging through the manual, looking up schematics, pinouts, power and ground circuits, etc. I finally figured it out. There are only two things that run off the "on" side of the switch. Everything else runs off "acc/on" or "run/start".
Guess what the two things are.... Climate control and oxygen sensor heaters.
Backtracking through the wiring, found the problem was in the ignition switch contacts. I was getting 0.2 volts on the yellow wire. Disassembled the ignition switch, filed the contacts, and everything started working again.
p.s. This was only after sending the unit off for repair, and still had the same problem when it came back. Then I knew I had to dig into the wiring. The 12v batt pin was hot, but the 12v switched pin was not.
Last edited by john_d.; May 25, 2015 at 08:35 PM. Reason: add one more thought...
Advanced
Joined: Jun 2015
Posts: 75
Likes: 1
From: Fort Hood Texas
I read the first few replies to this thread, and i was like hell yeah i can do this today. Then I came across one that said is it dim or dead. So my temp control works fine, but I don't see any sign of life from the display. Either it is so dim I can't see it or it is dead. So is it worth the time to attempt soldering it? Or is it a lost cause? You can trade them out on ebay, but it's not exactly cheap for such a small issue in my opinion.
Drifting
Joined: Mar 2010
Posts: 1,628
Likes: 15
From: Seattle WA
I read the first few replies to this thread, and i was like hell yeah i can do this today. Then I came across one that said is it dim or dead. So my temp control works fine, but I don't see any sign of life from the display. Either it is so dim I can't see it or it is dead. So is it worth the time to attempt soldering it? Or is it a lost cause? You can trade them out on ebay, but it's not exactly cheap for such a small issue in my opinion.