Actron SunPro CP7678, Operating Instructions Manual, Page: 9 / 36

250V MAX
15A MAX
FUSED
COM
DC
15A
20M
200
K
20K
2K
200 8CYL
6CYL
TACH
X10
5CYL
4CYL
8CYL
OHMS
15
A
9
Display should read typically 0.2
Ω
to 1.5
Ω
.
If display reading was greater than 1.5
Ω
,
check both ends of test leads for bad
connections. If bad connections are found,
replace test leads.
5. Connect RED and BLACK test leads
across component where you want to
measure resistance.
When making resistance measurements,
polarity is not important. The test leads
just have to be connected across the com-
ponent.
6. Turn multimeter rotary switch to de-
sired OHM range.
If the approximate resistance is unknown,
start at the largest OHM range and de-
crease to the appropriate range as re-
quired. (See Setting the Range on page 6)
7. View reading on display - Note range
setting for correct units.
NOTE: 2K
Ω
= 2,000
Ω
; 2M
Ω
= 2,000,000
Ω
If you want to make precise resistance
measurements, then subtract the test lead
resistance found in Step 4 above from the
display reading in Step 7. It is a good idea
to do this for resistance measurements
less than 10
Ω
.
Measuring DC Current
This multimeter can be used to measure DC
current in the range from 0 to 15A. If the
current you are measuring exceeds 15A, the
internal fuse will blow (see Fuse Replace-
ment on page 7). Unlike voltage and resis-
tance measurements where the multimeter is
connected across the component you are
Fig. 9
testing, current measurements must be made
with the multimeter in series with the compo-
nent. Isolating current drains and short cir-
cuits are some DC Current applications.
To measure DC Current (see Fig. 9):
1. Insert BLACK test lead into COM test
lead jack.
2. Insert RED test lead into "15A" test lead
jack.
3. Disconnect or electrically open circuit
where you want to measure current.
This is done by:
• Disconnecting wiring harness.
• Disconnecting wire from screw-on type
terminal.
• Unsolder lead from component if work-
ing on printed circuit boards.
• Cut wire if there is no other possible way
to open electrical circuit.
4. Connect RED test lead to one side of
disconnected circuit.
5. Connect BLACK test lead to remaining
side of disconnected circuit.
6. Turn multimeter rotary switch to 15A
DC position.
7. View reading on display.
If minus (-) sign appears on display, then
reverse RED and BLACK test leads.
Black
Red
Electrical
Device
DC
Voltage
Source