ISTM-ALL MDVR-2012_Q2_Ver 1.0
10/27
4.
Some tips for installation:
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1
）
12V natural gas anti-interference isolation
When install the MDVR in 12V natural gas vehicles, the MDVR device must be insulated with the body of the
vehicle. Get power for the MDVR from vehicle battery directly and make sure to install the power protector and
security device between the MDVR device and battery.
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2
）
Pay attention to the polarity of electric power switch control (polarity test method: disconnect control
switch, take a wire from battery negative polarity, test it with digital multimeter. Connect this wire by
black pen on the multimeter, then connect vehicle body with red pen. If the circuit is working, this means that
vehicle power switch control is positive. If not, it is negative. If the vehicle switch is negative, it is
necessary to deal with the insulation between MDVR device and the accessories.
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3
）
It is very necessary for 12V battery-powered vehicles to deal with the insulation between the MDVR device and
the accessories of MDVR.
5.
ACC cable requirements
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1
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ACC wire working principle
Actual wire: red is positive, black is negative, yellow is ignition signal.
The MDVR device does not work if yellow ignition signal wire is connected ground or nothing. Make sure ACC
voltage is higher than 7.5V (Please test the voltage before connection) before booting up the MDVR
system for ensuring normal operation.
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2
）
When the recording model for MDVR is timing recording, please make sure connect the yellow ignition signal
wire with battery positive polarity.
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3
）
Switch power level value
Ignition
signal
≤6V
Ignition OFF
≥7.5V
Ignition ON
6.
All the wires connected to the rear panel of the MDVR should be wrapped together. The high frequency signal
cables should be shield by protected device. The connection should be strong and firm. All lines cannot be
