Using Multimeters for checking
I have a feeling that this post may start a large debate, but I suppose that is what club together is all about. Many may not agree with me on this subject but it is what I have experianced;
In my opinion, using multimeters for detecting power sources or measuring is not always a good thing as they sometimes can misled an inexperienced operator, on many occasions a test probe incorporating a 12v 5w bulb (or there about's) is a much better device
for use on motor vehicles for many reasons. Multimeters only require one or two milliamps in order to function, as they require such little power they can give what is known in the trade as Ghost Readings, this is due to them measuring & detecting the presents
of any supplies etc "OFF LOAD", in other words, say you used a multimeter to find a 12v supply in order to tap into said power supply to power an auxiliary circuit/component, the multimeter may say "yes, this is 12v" but it may not nessasary mean that this
source can supply 12v under load. Another example, if you were using a multimeter to measure or detect a power source, it is possible that your multimeter could be in series with another component while trying to take a reading, as a multimeter takes such
low current to operate, you may not nessasary know that you are measuring in series with another component.
To this end, my advice is to use the multimeter at first, than when you think you have achived the goal, then carry out the same objective under load with the multimeter using a test probe at the same time.
Snowy