How to Buy Used Automotive Diagnostic Tools and Equipment

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How to Buy Used Automotive Diagnostic Tools and Equipment

When there is a problem under the hood, the imagination typically comes up with a million possible reasons. Cars built after 1996 have installed diagnostic software that allows professionals and mechanics to use a scan tool to determine the exact reason the car or motorbike is not working correctly. Most individuals do not own a scan tool, nor do they know how to use one, so this technology is normally only useful when a car is taken into a garage for a costly repair. Other diagnostic tools and equipment help determine what is wrong with a car without using software or a scan tool, but people do not necessarily own these tools either.

For people who want to avoid a trip to see a mechanic every time the engine light turns on, investing in an automotive diagnostic tool to 'read' their cars may be a smarter decision. Automotive diagnostic tools can be expensive investments, however, which is why buying used diagnostic tools to save money without sacrificing quality is worth considering. There are different tools for different purposes, and knowing the function of each diagnostic tool can help buyers decide which tools they need for their own personal use. Local automotive stores do not normally carry used products, but it may be possible to find diagnostic tools through secondhand channels like classified ads, or buyers can search on the Web on sites like eBay.

Using Automotive Diagnostic Tools and Equipment

The most common diagnostic method involves the scan tool. In order to take a diagnostic reading with this tool, several things are needed: a laptop, jack cables, port connector, scan tool or car code reader, and an understanding of the software in order to decrypt the codes and acronyms produced by the diagnostic software. Automotive diagnostic tools pick up readings from the built-in diagnostic software based on sensors in the engine, chassis, frame, and other parts on the automobile. The software translates the functions of each system into codes that are transferred to the diagnostic tool. This translation of coding paints a metaphorical picture as to where the problem is located.

The software has to be installed onto the computer for reading the scanner, and the scanner is connected to the port that is typically found on the dash near the steering wheel or underneath the driver's seat. The scanner tool comes with instructions on how to operate the tool and read the findings, which are sent to the computer in a series of codes. These codes are then translated using guidelines from the translation sheet that comes with the software or scanner.

Besides the scan tool, there are other diagnostic tools that are used to determine other problems. Gauges measure air pressure in the tires, temperature gauges measure the temperature of fluids and oil, and voltmeters measure battery power. Test lights check for proper electrical connections in order to diagnose various problems with a car. All of these can be helpful additions to a personal toolbox for fixing automotive problems before going to a mechanic.

Diagnostic Tool


Scan Tool

Main automotive diagnostic tool

Reads and decodes the vehicle's diagnostic software to determine the problem area

May require connectors or cables

Wireless scanners are available, as well

Test Light

Checks any positive circuit

One end connects to the positive power source like a battery

Other end connects to a ground, which is any exposed metal bolted to the chassis

Lights up when the positive voltage is working

Problem is diagnosed by finding the area where the light does not turn on

Tire Pressure Gauge

Measures the pressure level of air in the tires

Prevents accidentally adding too much or too little air to the tires

Coolant Temperature Gauge

Provides the engine temperature

Source of the 'Check Engine' light

Attached within the car near the thermostat housing

Battery Voltmeter

Measures voltage of the car battery

Red probe attaches to the positive metre

Black probe attaches to the negative metre

Comes with two settings: direct current (DCV) and alternating current (ACV)

DCV is for the car or household battery

ACV measures voltage from a wall outlet

Probes should be held by the rubber or plastic handles to avoid shock

Tire Tread Depth Measure

Measures depth in tire tread

Probe should be placed in the tire groove before pressing down on the gauge

There are all sorts of different diagnostic tools that address different possible problems with a vehicle or motorbike. Each one is a valuable addition to an individual's tool box and can help save money in the long run by identifying problems that do not require the help of a mechanic.

Safety Precautions When Using Used Automotive Diagnostic Tools and Equipment

While most diagnostic tools are safe, there are tools that require special care when operating. For instance, the battery voltmeter uses metal probes to connect directly with a power source. The vehicle should be turned off for an accurate reading, and the hands should be on the rubber or plastic wrappings on the probes. It is important to match the red probe with the positive node and the black probe with the negative node, although many voltmeters have safety features installed to prevent users from accidentally shorting out the voltmeter.

When checking on the coolant temperature gauge, the vehicle should be turned off and the engine should be cool before replacing it in order to avoid burning oneself. Protective eyewear and gloves are recommended to protect the body from hot liquids, metal, or other hazards that are involved in working under the hood.

Benefits of Used Automotive Diagnostic Tools and Equipment

Buying new diagnostic tools can be more expensive than the money spent on a mechanic, and for older cars, the diagnostic software may not be compatible with more modern scan tools. Buying used diagnostic tools saves money without sacrificing the quality or technology of brand new tools. Older, used diagnostic tools can also be found for older cars that pre-date the technology that is currently available in stores. Buying used automotive diagnostic tools and equipment helps auto owners identify the problems in their vehicles without paying a fortune.

Considerations When Buying Used Automotive Diagnostic Tools and Equipment

When looking for the right tools to add to one's garage, several factors should be considered. The first is the budget range that one is willing to spend on diagnostic tools. If the cost of the diagnostic equipment far exceeds the cost of going to a mechanic, then buying diagnostic equipment may not be the best choice. Used automotive diagnostic tools are meant to give the buyer the right tools for the right price.

The second consideration is frequency of use for the tools. If a car breaks down more often than it should, automotive diagnostic tools can only tell the user where more money needs to be spent. There may come a time when buying another vehicle or using a different mode of transportation is wiser than taking one's automobile to the shop for the third time in a month.

The third consideration is the user's ability and willingness to fix one's own vehicle or motorbike after the problem is diagnosed. Being able to use diagnostic tools is helpful, but if a person cannot fix his or her own car after the issue is diagnosed, then owning diagnostic tools is not necessarily all that helpful since the vehicle still has to go to a mechanic for repairs.


Going to a mechanic for every little car problem becomes time consuming and expensive, especially when the solution is something that could have been handled at home. Making the investment in automotive diagnostic tools, such as a scan tool, to read a car's built-in diagnostic software may be a wise choice for people who are capable of making some car repairs on their own. Other diagnostic equipment, such as voltmeters, test lights, and temperature gauges, also help diagnose issues with vehicles.

New diagnostic tools may be out of the price range for many individuals, depending on the level of technology that is purchased. Fortunately, used automotive diagnostic tools and equipment come at a lower price without sacrificing the quality of the equipment. In fact, used diagnostic tools may sometimes be the only option for matching the diagnostic software in older car models. A variety of automotive diagnostic tools can be found online on the eBay site and other retail sites, or buyers can attempt to find them for sale in local classified ads.

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