terminals. See Fig. 1. Select 10-amp scale.
3) Turn off all electrical accessories. Turn off interior
lights, underhood lamp, trunk light, illuminated entry, etc. To avoid
damaging ammeter or obtaining a false meter reading, all accessories
must be off before turning test switch knob to OFF position.
4) Turn test switch knob to OFF position to allow current to
flow through ammeter. If meter reads wrong polarity, turn test switch
to ON position and reverse leads. Turn test switch to OFF position.
Observe current reading. If reading is less than 2 amps, turn test
switch to ON position to keep electrical circuits powered-up.
5) Select low amp scale. Switch lead to the correct meter
position. Turn test switch to OFF position and compare results to
normal current draw. See the GENERAL MOTORS PARASITIC LOAD TABLE . If
current draw is unusually high for the vehicle's overall electrical
system, remove system fuses one at a time until current draw returns
to normal.
6) Turn test switch to ON position each time door is opened
or fuse is removed. Turn switch to OFF position to read current draw
value through meter. When the cause of excessive current drain has
been located and repaired, remove test switch and reconnect negative
battery cable to the negative battery terminal.
Fig. 1: Connecting Kent-Moore Disconnect Tool (J-38758)
Courtesy of General Motors Corp.
GENERAL MOTORS PARASITIC LOAD TABLE (MILLIAMPS)
\
\
\
\
\
\
\
EXAMPLE #2 - VOLTAGE CONTROLLED DRIVER
This time we will look at a GM 3.1L V6 VIN [T]. Fig. 8 shows
the 1, 3, 5 (odd) injector bank with the current waveform indicating
about a 2.6 amp draw at idle. This pattern, taken from a known good
vehicle, correctly stays at or below the maximum 2.6 amps current
range. Ideally, the current for each bank should be very close in
comparison.
Notice the small dimple on the current flow's rising edge.
This is the actual injector opening or what engineers refer to as the
"set point." For good idle quality, the set point should be uniform
between the banks.
When discussing Ohm's Law as it pertains to this parallel
circuit, consider that each injector has specified resistance of 12.2
ohms. Since all three injectors are in parallel the total resistance
of this parallel circuit drops to 4.1 ohms. Fourteen volts divided by
four ohms would pull a maximum of 3.4 amps on this bank of injectors.
However, as we discussed in EXAMPLE #1 above, other factors knock this
value down to roughly the 2.6 amp neighborhood.
Now we are going to take a look at the even bank of
injectors; injectors 2, 4, and 6. See Fig. 9. Notice this bank peaked
at 1.7 amps at idle as compared to the 2.6 amps peak of the odd bank (
Fig. 8 ). Current flow between even and odd injectors banks is not
uniform, yet it is not causing a driveability problem. That is because
it is still under the maximum amperage we figured out earlier. But be
aware this vehicle could develop a problem if the amperage flow
increases any more.
Checking the resistance of this even injector group with a
DVOM yielded 6.2 ohms, while the odd injector group in the previous
example read 4.1 ohms.
Fig. 8: Injector Odd Bank w/Normal Current Flow - Current Pattern
![MITSUBISHI MONTERO 1998 Service Manual EXAMPLE #2 - VOLTAGE CONTROLLED DRIVER
This time we will look at a GM 3.1L V6 VIN [T]. Fig. 8 shows
the 1, 3, 5 (odd) injector bank with the current waveform indicating
about a 2.6](/manual-img/19/57333/w960_57333-1443.png "MITSUBISHI MONTERO 1998 Service Manual EXAMPLE #2 - VOLTAGE CONTROLLED DRIVER
This time we will look at a GM 3.1L V6 VIN [T]. Fig. 8 shows
the 1, 3, 5 (odd) injector bank with the current waveform indicating
about a 2.6")