
What is a receiver drier?
March 29, 2022
With A/C season just around the corner, this seems like a good time to provide some updated information on these units. NOTE: Receiver driers are sometimes called filter driers and accumulators are sometimes called accumulator driers.Read Article >

Refrigerant supply, pricing and safety
March 8, 2022
What I'm hearing about refrigerant supply and pricing this year reminds me of a similar period in the mid-2000s. It was springtime, just before the start of A/C season. Supplies of R-134a were tight and the price had come close to tripling from the prior year.Read Article >

Refrigerant reminders
March 1, 2022
It could be a challenging year keeping adequate supplies of R-134a on hand and it will be more expensive.Read Article >

Air contamination in mobile A/C systems
January 18, 2022
We covered a base line test conducted with 0% air contamination and provided pressure and temperature information. This week we will provide pressure and temperature information experienced with 7.7% air contamination and 18.9% air contamination.Read Article >

When you don’t know about clutch wires
December 27, 2021
The conversation involved a clutchless compressor unit. A CSR who had sold one to a shop contacted me and said his customer (who was both the shop owner and technician working on the car) had just called him. There was a concern that the compressor didn't have a clutch wire.Read Article >

The pulse width modulated duty cycle signal
December 7, 2021
Several years ago, when vehicles using these compressors were just starting to show up at shops for service with some regularity, we were searching to find some detailed information about their behavior to use in clinics. There was not a lot of it available, so we borrowed several vehicles and did some videos. The following are some clinic slides produced from one of those videos.Read Article >

Diagnosing electronically controlled compressors
November 30, 2021
When preparing to conduct diagnostics on a system using an electronically controlled variable displacement compressor, the diagnostic process needs to focus on four areas.Read Article >

Exploring electronically controlled variable displacement compressors
November 23, 2021
Electronically controlled variable displacement compressors (ECVDs) have been in use now for over 15 years. However, there are a lot of technicians in the field who have very little knowledge about them and their operation.Read Article >

EPA releases Automotive Trends Report
November 19, 2021
Vehicle enthusiasts may want to check out the U.S. EPA's newly released Automotive Trends Report.Read Article >

Electronically controlled variable displacement compressors
November 16, 2021
what if" this system used an electronically controlled variable displacement compressor instead of the pressure controlled variable displacement compressor? What would the results be?Read Article >

Meet MACS member, Tom Lech
November 8, 2021
Stationed in San Francisco, California, Thomas Lech has maintained a bustling business for almost three decades. Lech Auto Air Conditioning has been busy for 365 days a year from opening at 7 a.m. to closing at 7 p.m. for the last 27 years, with summertime only increasing the demand for the shop’s services.Read Article >

What do you know about the fixed displacement piston compressor?
November 2, 2021
What do you know about the fixed displacement piston compressor?Read Article >