No drier replacement, no compressor warranty!
April 6, 2022
Compressor manufacturers and parts distributors are adamant about driers being replaced when one of their compressors are installed. No drier replacement, no compressor warranty!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 >
Sometimes it is user error
February 8, 2022
I encountered a situation in the early days of recovery/recycling machines when they had just been introduced. I had set up a machine about four months earlier when the customer purchased it. I went to great lengths to cover proper operation of the unit and the shop owner even attended a certification clinic I conducted.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 >
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 >
J1587/J1708 and J1939 data line diagnostics
October 27, 2021
Modern heavy-duty equipment is basically comprised of computers with operating units attached. In short, it is a multiplexing system that replaces traditional power distribution devices with ECUs that communicate electronically over the vehicle datalink.Read Article >
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.Read Article >
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.Read Article >
