Wanted C5 Climate control unit
- Thread starter BMAndyval
- Start date
teamzr1
Supporting vendor
Before looking for another HVAC head
It is common for solder joints to crack and easy to open the unit and reflow solder joints
Here is one that I fired up on my work bench to debug and repaired and problems went away
Look at these, the resistor packs are surfaced mounted and joints were cracked
Resoldered them and the unit has been like new 7 years after working on this
It is common for solder joints to crack and easy to open the unit and reflow solder joints
Here is one that I fired up on my work bench to debug and repaired and problems went away
Look at these, the resistor packs are surfaced mounted and joints were cracked
Resoldered them and the unit has been like new 7 years after working on this
Sorry to hijack the thread but are these resistor packs the reason for the HVAC not illuminating? My unit works fine but the lights are dead as a dodo.
teamzr1
Supporting vendor
Yes Sir
Look at the first photo and see how dim the numbers are
and then the second photo is after I reflowed the solder joints of the resister packs, see how bright the numbers are
The third photo is from a newer model and notice the packs are differently laid out but also fixed the HVAC controller after I reflowed the solder joints of the packs
Look at the first photo and see how dim the numbers are
and then the second photo is after I reflowed the solder joints of the resister packs, see how bright the numbers are
The third photo is from a newer model and notice the packs are differently laid out but also fixed the HVAC controller after I reflowed the solder joints of the packs
Last edited:
teamzr1
Supporting vendor
The cracks in the solder joints are slight so have to look real close
I suggest go ahead and reflow solder joints on all of them if you cannot see the cracks
These packs are surface mount so do not reflow both sides at the same time to prevent pack lifting from circuit board
Do one end of each and then the other sides of each
I suggest go ahead and reflow solder joints on all of them if you cannot see the cracks
These packs are surface mount so do not reflow both sides at the same time to prevent pack lifting from circuit board
Do one end of each and then the other sides of each
teamzr1
Supporting vendor
This is a write-up I did in 2019 on my forum
There is a common failure point for all C5 HVAC controller head in where the LCD screen the output goes dim and in sunlight cannot even be seen to make adjustments for what you want in HVAC
Replacement HVAC units today costs as much as $600 plus yours as a core but since GM quit using these are harder to find these for sale
Some vendors do have a repair service where you have to mail them the unit and then have the downtime to get the unit back to them
Many charge $75 plus and the cost of round trip shipping
This could take from 1 to 2 weeks
Here is an example of fixing this common failure point :
There are eight resistor packs, on top they say "241"
Over time due to heat the soldering joints from them crack causing lower voltage to the LCD screen
Take the HVAC unit out of the console, there is only 1 small mounting screws at each end.
Disconnect the wiring harness from the unit
Remove 4 small screws on the back side to crack open the rear and front cases.
Lift up the rear daughter board out of that back case
Turn over and look for eight resister packs labeled 241
Use a low wattage soldering iron with thin solder
Re-solder both ends of each of the 8 resister packs, do not overheat them
Best is re-solder just one end of each and then let them cool a few minutes and then re solder the other ends
So that is 16 solder joint ends
While the unit is open lift the front daughter board by removing 4 small screws (1 per corner) and there is several LED as lights and the LCD screen and the lens for it and clean them
Reverse the process in putting the HVAC unit back together and then reinstall back into the console
Before installing center console, turn Ign key to ACC and assure LCD now reads clearly
Cost is zero if you have small soldering iron and thin roll of solder, otherwise maybe spent $25 for them and use for other projects
Here is before and after re-soldering was done (shown in my other post today)
NOTE :
To show this, I traced what each wiring pin was for and then temporarily hooked up voltages and ground to make the LCD screen viewable
Not something you need to do
There is a common failure point for all C5 HVAC controller head in where the LCD screen the output goes dim and in sunlight cannot even be seen to make adjustments for what you want in HVAC
Replacement HVAC units today costs as much as $600 plus yours as a core but since GM quit using these are harder to find these for sale
Some vendors do have a repair service where you have to mail them the unit and then have the downtime to get the unit back to them
Many charge $75 plus and the cost of round trip shipping
This could take from 1 to 2 weeks
Here is an example of fixing this common failure point :
There are eight resistor packs, on top they say "241"
Over time due to heat the soldering joints from them crack causing lower voltage to the LCD screen
Take the HVAC unit out of the console, there is only 1 small mounting screws at each end.
Disconnect the wiring harness from the unit
Remove 4 small screws on the back side to crack open the rear and front cases.
Lift up the rear daughter board out of that back case
Turn over and look for eight resister packs labeled 241
Use a low wattage soldering iron with thin solder
Re-solder both ends of each of the 8 resister packs, do not overheat them
Best is re-solder just one end of each and then let them cool a few minutes and then re solder the other ends
So that is 16 solder joint ends
While the unit is open lift the front daughter board by removing 4 small screws (1 per corner) and there is several LED as lights and the LCD screen and the lens for it and clean them
Reverse the process in putting the HVAC unit back together and then reinstall back into the console
Before installing center console, turn Ign key to ACC and assure LCD now reads clearly
Cost is zero if you have small soldering iron and thin roll of solder, otherwise maybe spent $25 for them and use for other projects
Here is before and after re-soldering was done (shown in my other post today)
NOTE :
To show this, I traced what each wiring pin was for and then temporarily hooked up voltages and ground to make the LCD screen viewable
Not something you need to do
C5Steve
CCCUK Member
I've done this, one tip. Buy a cold heat soldering iron, it'll prevent you overheating the joints and damaging the resistors. That's it you've never really soldered before (or like me, very infrequently). They're under £20 and battery powered so very easy to use.
It's a simple job, just take your time. Makes a huge difference.