[VAC] Electrical Safety

["john or cindy" <jyoung@xxxxxxxxxxx>]

Hello Airstreamers
I just read about 12 volt dc testing of live circuits. I'm  mechanic, I
agree with the advice to use a fused jumper. I ALWAYS use  jumper wires with
an in line fuse. This is an easy thing to make, go to Radio shack or the
auto parts store & buy the cheap jumper wires with the clips on each end.
Also buy a FLAT type "inline fuse" & some crimp butt connectors form the
same place. Cut the jumper near one of the clips & install the inline fuse
with crimp butt joints or solder joints with shrink wrap insulation. The
modern flat fuses will accept "self resetting" circuit breakers for those
that don't want to keep replacing fuses. The neat thing about a fuse
protected jumper wire is you can choose the size fuse for each job , (don't
just put a big fuse in the jumper to save replacing it). Also remember that
you are working on vintage circuits without computers. If you try to use
this on your newer tow vehicle, you stand a chance of hurting some modern
electronic system resulting in a big repair bill. The new computer systems
can be hurt by something as benign as a good old fashioned 12v test lamp if
testing a venerable system. There are new test lamps (high impedance) that
are safe for automotive computers, mine even tells me of polarity .
John Young