Tool Review: Lisle Relay Pro 12V and 24V Relay Tester

Feb. 7, 2022
Reviewed by Ken Elzinga, diagnostic technician and owner of Hilltop Auto Service in Byron Center, Michigan.

Q: How did the tool/equipment function as far as saving you time? 

A: The tester was time-saving because with this tool we were able to quickly give a pass/fail result to a suspect relay. This tool allows the tech to make that decision quickly and with confidence instead of relay swapping or hooking up jumper wires and a battery to try to test it.  

Q: What types of jobs did you use this tool for?  

A: We encountered many intermittent A/C compressor relay faults. This was the most used example of the tool. We also used it on some ride control compressor relays and a few fuel pump relays.  

Q: What kind of setup was involved before using the product? 

A: No real setup of the tool was necessary. Technicians just have to understand the different terminals of the relay and hook up the tool accordingly. 

Q: How easy was it to use?  

A: The tool was easy to use and comes with good instructions for hooking the tool up to test a relay. 

Q: How was its packaging? Did it come with any accessories?   

A: Packaging was appropriate for this tool; all needed accessories were included. This means that the necessary terminals were included to hook up to various relays that would be tested.  

Q: Was there a manual included? 

A: There was a manual included and it gave good instructions for hook up and performing the test. It was easy to understand for a tech that is fluent in electrical testing.  

Q: What features did you like?   

 A: I think the ability of the tool to test a relay under a load and multiple times is helpful in identifying faulty or intermittently failing relays. This is the most valuable function of this tool given the many systems that are controlled by relays and the intermittent nature of relay failures.   

Q: Is there any way you could think to improve or add to this tool? 

A: There are new electronic relays that are starting to be used in our industry. Possibly an updated tool to test these relays would be helpful. Some of these relays are pulse width controlled and are difficult to test. A tester that would give a pass/fail would be helpful.  

Q: On a scale of 1 to 10, how would you rate this tool overall?  

A: I would give it a 10. Lisle continues to come out with innovative tools to help the techs who are working on today’s cars, and this is a good but inexpensive tool for anyone who does electrical diagnosis.  

 *Note: This product was given to the reviewer free of charge from the manufacturer.

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