Post Number: 8
|Posted on Saturday, 08 November, 2003 - 23:36: |
Here is a simple diode test DIY.
It is not possible to test diodes in circuit; diodes must be isolated from the circuit to be tested.
The most basic description of a diode: a one way electrical valve.
Here is a simple test procedure I use:
Two alligator clip jumper wires, a crayon, a permanent marker, a note pad and pen, a small plastic or rubber mat, a five amp Maxi fuse, a car battery and a test light are needed.
Take all diodes and mark one terminal on each with the crayon.
You may want to number mark each diode also.
#1. Connect one jumper to battery ground and connect the other end to one leg of a 5 amp Maxi fuse.
#2. Connect the test light clip to the other leg of Maxi fuse.
#3. Connect the other jumper to battery +12 terminal and the other end to
the selected diode on the crayon marked end, lay the connected diode on the plastic or rubber mat.
#4. Touch the probe end of test light to the unconnected end of diode, if it lights, make a note, if it does not light, make a note.
#5. Remove jumper wire from crayon end of diode and attach to unmarked end of diode, lay the connected diode on the plastic or rubber mat.
#6. Touch the probe end of test light to the unconnected end of diode, if it lights, make a note, if it does not light, make a note.
Diagnostic chart for this test:
"Bad diode" Light comes on with diode attached in both directions.
"Bad diode" No Light with diode attached in either direction.
"Good diode" Light with diode attached in only one direction.
RROC, Lake Michigan, Motor and Ohio region.
ASE Master Mechanic
45671 Woodward Avenue
Pontiac, MI 48341
Work Phone 248-334-6400 Fax 248-334-2363