Bendix Commercial Vehicle Systems MC-30 TRAILER ABS CONTROLLER - Manual (Page 29)

29
SECTION F - TROUBLESHOOTING POWER TO THE MC-30 ™ CONTROLLER
D u e t o c o r r o s i o n , d a m a g e o r
poor termination, the wiring and/
or connectors may be limiting the
electrical current fl ow to the MC-30
™
controller. This means that when the
MC-30
™ controller needs more current,
the voltage level may be dropping. In
order to measure the voltage under
load, place a load such as a type 1157
brake light bulb between pin E1 and
ground pin D2 at the 30-pin connector.
Supply ignition power to the trailer and
measure the voltage across the pins
while the lamp is in place. Repeat the
loaded measurements using brake light
power and pins E3 and D2 at the 30-pin
connector.
The operating range of the MC-30 ™
controller is 8.0-16.0 VDC. Verify a
measurement equal to battery voltage.
(About 12.0 VDC) The loaded voltage
should drop no more than 1.0 VDC from
the measured unloaded voltage.
T h e g r e e n V LT L E D i s o f f o r
fl ashing.
The MC-30
™ controller may not function
properly when powered with a battery
charger or other similar device. Power
the MC-30
™ controller using a battery
or clean power supply.
Turn off power to the MC-30 ™
controller and disconnect the 30-pin
connector.
Supply ignition power to the trailer and
measure voltage between pin E1 and
ground pin D2 at the 30-pin connector.
Supply brake light power to the trailer
and measure voltage between pin
E3 and ground pin D2 at the 30-pin
connector.
The operating range of the MC-30 ™
controller is 8.0 -16.0 VDC. Verify a
measurement equal to vehicle voltage at
both power inputs. (About 12.0 VDC)
With a volt/ohm meter, check the
power and ground wiring. Look
for corroded or damaged wires or
connectors. When repair is made,
reconnect the 30-pin connector to
the MC-30
™ controller and rerun the
power up sequence.
Go to Section A.
With a volt/ohm meter, check the
power and ground wiring. Look
for corroded or damaged wires
or connectors. If repair is made,
reconnect the 30-pin connector to
the MC-30
™ controller and rerun the
power up sequence.
Go to Section A.
Measure the loaded
voltage across a type
1157 brake light bulb.
1
2
3
K J H G F E D C B A
30-Pin Connector
YES
NO
E1 Ignition Power
E3 Brake Light Power
D2 Ground
If proper loaded and unloaded voltage
is measured at the 30-pin connector
and no corrosion or damage is found
on the wiring, connectors or ECU,
replace the EC-30T
™ controller.