This may be issues with all vehicles but to show how heat degrades controllers in GM vehicles where I have seen and repaired the damage

Focus on controllers like the HVAC head, door and EBTCM is common for these to start acting oddly Here is an example of the HVAC controller where it does not work correctly or the LCD screen is very dim

[Dim HVAC Srreen]

[Contents of LCD Very Dim]

Using GM service manual looking at the wiring for the HVAC I did what was needed to make the controller active and closely looking at solder joints found due to heat the solder joints are very thin caused cracks

[Surface Mounted Resister Packs]

Debugging the electronics board, the resister packs found the joints cracked You need to look very closely and also look for heat coloring

Once I had reflowed the solder joints, tested and now the contents of LCD was bright again even in sunlight

[Once Reflowing Solder Joints]

I find issues like this also with door controllers, EBTCM and IPC

John Rovner
Owner
Team ZR-1 Corvette Racers llc
Greenville, Texas, USA

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