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Diagnostics & Scan Tool

The concept of superheat

October 19, 2021

We illustrated the concept of superheat in last week's article by boiling water and superheating steam in a moonshine still. This week we will apply this concept to refrigerant in an air conditioning system.  The still has been replaced with an evaporator. 
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Understanding and troubleshooting data lines on heavy-duty trucks

September 23, 2021

Understanding and Troubleshooting data lines on heavy-duty trucks will be presented byLarry Turay of LETCO Enterprises. In Larry’s Saturday morning class, attendees will learn how components and subsystem inputs and outputs can influence HVAC operations. 
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Cooling fan circuit analytics

September 16, 2021

What is Peter Orlando’s class Cooling Fan Circuit Analytics about? It all began decades ago as a mechanical fan attached to the water pump with and without a fan clutch.  And now it has evolved into an efficient complex electrical motor control of cooling the modern internal combustion engine.
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Mind the compressor clutch gap

August 31, 2021

One of the first things I was taught in my A/C training was to always check the clutch air gap prior to installing a compressor. 
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Two clues to a condenser’s identity

August 24, 2021

There are two steps to determining what type of condenser is in a vehicle.
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What type of condenser is in that vehicle?

August 17, 2021

What type of condenser is in that vehicle? It's a frequent question in the mobile A/C industry.
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Mysterious servicing issue in R-1234yf systems

August 11, 2021

Recently a 2017 R-1234yf Honda system, with 72,099 miles, encountering a loss of cooling (slow leak) over time would not pass the equipment charge procedure and the production amount could not be charged. 
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Field study: Incorrectly installed condensers

August 10, 2021

I have handled numerous tech calls involving older GM trucks with incorrectly installed condensers.  In preparation for this series of MACS blogs, I discovered a salvage truck with one of these condenser repairs.  This gave me the opportunity to duplicate the incorrect installation and look for pitfalls and solutions.
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Did you install the condenser upside down and backwards?

July 27, 2021

The vehicle was a 1998 Chevrolet C 1500 truck with a 5.7 engine. The issue was excessive high side pressure. Almost as soon as the compressor clutch engaged, the high side pressure was over 400 PSI, and the high-pressure cut-off was turning the compressor on and off.
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Top three tips on orifice tube behavior

July 20, 2021

In the last four MACS blog articles we covered a lot of detailed information about orifice tube system behavior. We examined a system with a full refrigerant charge verses a 25% undercharge. Now it is time to condense it all down into three important takeaways.
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