The 25+ - The Problem with Bench Testing

#23. Why is it that some switches/loads/circuits can’t be “bench” tested? Why do they have to be installed in the car and tested with the car ON and running?

Truth be known, anything can be bench tested IF the test accurately and completely represents the real world circuit that will be present in the car, in use. But that’s a big “IF”.

When was the last time you prepared to do a bench test by drawing out the circuit diagram? When did you double check you power supply to make sure it was sufficient? And worse yet, when was the last time you started to do a bench test with “live” power and fried a component? These are just a few of the issues with bench testing.

Even when testing is being done in the car, a lot of people figure that their battery is fully charged (even though the car hasn’t been started once during the last two weeks of testing). They put a trickle charger on the battery, so it must be good. Or they are just using the battery charger all by itself to do the testing, never considering the voltage and amperage output versus the parts need. A part doesn’t work quite right and they assume the worst.

We even see a certain group of customers who must have gotten burnt (pun intended) in the past, who have to - by their genetic makeup - bench test every single thing that they buy. Invariably, the part fails their bench test and they have been “burnt again”, never realizing that it is their testing that is the problem. Still another small group will be doing a major electrical installation and feel the need to connect power and test the last circuit that they installed, although they are still far from completion. This is a open invitation to problems - connecting power to an entire system while only part of it is done.

So, go ahead and bench test (because we know that you will anyway), but do it wisely. And if something doesn’t work right, please, question your testing before you call and blame the part for being faulty.

Steve Watson, Watson's StreetWorks, http://www.watsons-streetworks.com