Well, it looks like the battery charger caused more damage, the HVAC has gone into "over-drive" and trying to cool the cabin (similar to this thread)

Thanks to the now fixed Tech2, I see the inside temperature is way-off :-


It certainly is not 123F (50.5C) I can only assume its either a damaged HVAC control module, or the Inside Temperature Sensor.

Something more concerning was that the engine seems to run hot, though the indicated engine temperature seemed normal and yes there is plenty of coolant.

The instrument cluster gauge reads (not fully up to temp yet) :-



The Tech2 Engine Coolant temp value reads :-



So that's 188F which is 86.7C which is about right, fairly close to the gauge.

Could it be the engine runs hot because the cabin is constantly being cooled i.e. no warm air flow through the cabin?

Just going to measure the ambient air sensor at the IP Relay block to get some idea of what's wrong.

 

Traced the wiring back to IP Fuse Block connector C3 pins K (signal) and G (low ref) the voltage measured 2.381V at approx 54°F (driver's door open)


Note the I/P Fuse Block is easy to access just between the E-Brake and brake pedal.

Applied some freezer spray to the sensor and the voltage dropped to 2.170 (negative co-efficient) so I'd say the sensor is fine, after all its only a resistor.

The Tech2 always showed 122°F i.e. no change, so it looks like the HVAC Control Module is faulty, probably the microprocessor's ADC input for that channel has blown.

Of course I'll pull-out the unit and see if I can fix it as they seem very expensive, any suggestions much appreciated.... (it's been a bad year for parts)

 

188°F is low, 195°-210°F (90°-99°C) is normal operating range for engine temp.

 

As I mentioned, it "wasn't fully up to temp yet" just a snapshot during diagnostics. It usually tucks in somewhere in between where it's currently shown and 100 on the gauge, but I will check it, thank you for the correct figures.

 

A question for the forum.
My HVAC Control Module (Climate Control) is GM 10399657

So would a Chev Trailblazer part work the same. This add from eBay show the following as being compatible:-

Interchange Part Number: 10367041, 10367042, 10399657, 15077479, 15079112, 15085358, 15085358, 15105215, 15105969, 15107730, 15107730, 15132070, 15132070, 15133519, 15136332, 15137655, 15165918, 15175897,21999163

There seem to be a lot of variation in prices, all I actually need is the CPU chip or PCB.


Be grateful for any suggestions on the cheapest solution, its been an expensive couple of months ...

 

For example this one on eBay is quite cheap and ships to the UK, its GM 15165918 which is a member of the above list (if the list is reliable)

Any thoughts?

 

Do you read the "Description"?
Chevy Silverado 1500 Dorman 599-211 Climate Control 10367041; 10367042; 10399657. Condition is "Used". Shipped with USPS Priority Mail.That's a used dorman part.?

New--> HVAC Control Module Dorman 599-211XD

 

 

for my 2003 i used one out of a 2003 taho

 

Ah hummerz you were taking it easy on me, in fact it's a VERY used TATTY looking Dorman that's seem some action.🥺

In my defense, it was thinking I could put the electronics into my unit which is in good condition, that's assuming a Dorman is similar in construction.

Thanks for the list, most helpful 👍