What to do when your A/C is not blowing cold air?

There is definitely a problem when you observe that your car’s A/C is blowing warm air instead of cold air. It’s very frustrating especially during hot summer. One reason could be insufficient refrigerant due to some leakage.

But when you encounter this problem and you hear a very constrained hissing sound from the evaporator side (passenger side), then that’s a sign of a malfunctioning expansion valve. One effect also when you have malfunctioning expansion valve is that the engine idle speed drops significantly when the compressor motor kicks in.

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My ASEMEP Technical Papers

ASEMEP_Award_2015_b

I just want to have this page as repository for my technical papers presented at the annual ASEMEP  National Technical Symposium (Association of Semiconductor and Electronics Manufacturing Engineers of the Philippines).

  • “QFN Fine Pitch Packaging Design and Manufacturing Challenges”, 22nd ASEMEP National Technical Symposium, June 7-8, 2012 (Awarded Overall Best Paper)

ASEMEP – QFN Fine Pitch Packaging Design and Manufacturing Challenges

  • “Understanding the Mechanical Behavior of Thin Packages During Die Attach Curing Process,” 25th ASEMEP National Technical Symposium, June 4-5, 2015 (R&D Special Award)

Understanding the Mechanical Behavior of Thin Packages During Die Attach Curing Process

  • “Burn-in Oven Modeling Using Computational Fluid Dynamics (CFD)”, 13th ASEMEP National Technical Symposium, June 19-20, 2003

ASEMEP Paper – Burn-in Modeling

  • “Understanding Silicon Die Fracture Strength Using Weibull Analysis”, 14th ASEMEP (Association of Semiconductor & Electronics Manufacturing Engineers of the Philippines) National Technical Symposium, June 17-18, 2004

ASEMEP_Weibul_Die_Crack

  • “Using Finite Element Analysis in Understanding Package Moisture Absorption Behavior”, 22nd ASEMEP National Technical Symposium, June 7-8, 2012

ASEMEP – Using Finite Element Analysis in Understanding Package Moisture Absorption Behavior

  • “Understanding and Eliminating Wire Bondability Problem on Overhang Stacked Die,” 23rd ASEMEP National Technical Symposium, June 2013

Understanding and Eliminating Wire Bondability Problem on Overhang Stacked Die R1 (2)

  • “Elimination of Delamination and Solder Flow-out in a New SiP with Large SMD,” 23rd ASEMEP National Technical Symposium, June 2013

Elimination of Delamination and Solder Flow-out in a New SiP with Large SMD R1

  • “Optimization of Stacked Die QFN Package Reliability Through Design and Virtual Prototyping,” 23rd ASEMEP National Technical Symposium, June 2013

Optimization of Stacked Die QFN Package Reliability Through Design and Virtual Prototyping

  • “The Effect of Glue Bond Line Thickness and Fillet Height on Interface Delamination,” 23rd ASEMEP National Technical Symposium, June 2013

The Effect of Glue Bond Line Thickness and Fillet Height on Interface Delaminationx

 

Other ASEMEP papers supported:

A Systematic Approach in Optimizing Strip Warpage of Quad Flat No-lead Package Rev 1

ELIMINATION OF VOIDS AND DELAMINATION BY OPTIMIZING SUBSTRATE DESIGN

Citation (IEEE Reference [6]):

01638762_Die_Fracture

 

 

Paper Awards:

Category_Best_Paper2012

Overall_Best_Paper2012

ASEMEP_RnD_Award 2015

Category Best Paper 2017

What to do when your car A/C blower stops working?

When your car aircon blower stops working on lower speeds (commonly speed “1”), then the most likely culprit is the blower motor resistor. Usually when you have resistor damage, the blower would still work on the highest speed (“4”).  The figure below shows the typical blower motor resistor diagram.

Typical Resistor Diagram

So when your car A/C blower stops working, there’s a quick fix to make it working again. And you don’t need to spend money or go to the auto repair shop when you can do it yourself easily.

Here is what I did and the blower is still working for more than a year now.  First, I needed to locate the resistor.  The usual location is near the blower motor behind the glovebox in the front passenger seat. Second, I removed the glovebox and then the resistor. Third, I checked for broken wire coil connections and joined them by twisting the wire ends together.  And finally, I put back the resistor and the A/C was up and blowing cold air on all speed settings!

resistor1resistor2

Basic Car Troubleshooting

When car is getting old, the need to know basic troubleshooting ismy_car becoming necessary. There are several resources on the internet (e.g. forums) and I will just be putting some items here that I have also encountered while maintaining an old car.
==> A/C blower speed increases and headlights brighten intermittently without any pattern
– Possible Cause: Alternator is failing or some connections (maybe for the ECU) are disabled
– Solution: Replace the alternator

==> A/C blower speed increases and headlights brighten when accelerating
– Possible Cause: IC voltage regulator is not working
– Solution: Replace the alternator (though some would just replace the regulator)

==> Tail light (dual filament type) is not working for the first few minutes but is later functioning
– Possible Cause: One of the filaments is already failing. If the other filament (for brake light) is still working, it also heats up the neighboring filament and may establish connection after some time of driving.
– Solution: Replace the light bulb (not expensive)

==> Right/left turn signal light blinks faster than normal
– Possible Cause: At least one bulb is out.
– Solution: Look for burned-out bulbs and replace.

==> Engine is overheating even during early morning drive
– Possible Cause: Some of the radiator tubes/ coolant passages are already blocked; leaks from radiator tubes or the rubber hose connecting radiator to the engine; radiator cooling fan is not working
– Solution: Repair/replace the radiator or replace defective cooling components

==> Squealing, screeching or chirping noise under the hood
– Possible cause: Incorrect belt tension; belt pulley misalignment
– Solution: Adjust belt tension to the correct specification; correct any misalignment

==> Tires loosing pressure fast
– Possible Cause: Leaking tire valve; leaking rim; tire puncture
– Solution: Replace tire valve; lightly buff the tire bead and wheel’s rim; patch/ vulcanize tire

==> Knocking or popping sound when going over road humps/bumps
– Possible Cause: Worn-out shock absorber (or check also other components of the suspension system)
– Solution: Replace shock absorber or other suspension components

==> Radiator leaks
– Solution: Solder those leaking areas of the radiator; use “stop leak” liquid (e.g. Mag1), which would work well for small leaks based on my experience.

What to do when your car A/C blower stops working?

What to do when your A/C is not blowing cold air?