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12V Power Adapter Warning

It has come to our attention that there are some  cheap "universal" 12V laptop adapters which should NEVER be used while scanning a car.

One example is Radio Shack part number 237-1827:

Do not use this Adapter!  On at least some laptops, this adapter will put the laptop's ground at a hard potential substantially different than the car's ground.   This can damage or destroy your interface!     Page 9 of Radio Shack's own manual for this part states:

Our interfaces are indeed "peripherals" which are powered by the car directly! 

In our opinion, the design of this particular 12V adapter is defective.   There may be other cheap universal adapters which have the same design defect.    Damage to  interfaces caused by defective 12V adapters will not be covered under our warranty!

If you are in doubt about the 12V adapter you already have, there are several ways to test for this defect, depending on what electronic test equipment you have available.   The ideal method is connect your laptop to your car with the 12V adapter in question (but no interface!) and measure both AC and DC current between the laptop's ground (one of the screw receptacles on the VGA port) and the the car's ground.   If the current is low (a few mA) then the adapter is safe.   If the current exceeds a few 10's of mA, then it likely is not.

If you are looking for a high-quality 12V adapter which is known to be safe, we can recommend the the Auto-Air Adapters from Lind Electronics.

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                    12V Power Adapter Warning