8A089X01 Rev 1
SLIM Installation Manual
3/23/2018
Page 58 of 61
Chapter 5
Best Practices: Installation &
Troubleshooting
In this section are recommended vehicle installation practices that can address or prevent
many issues.
5.1 Check Wiring of Ignition Sensing
•
If it is required to turn the Module on and off via the ignition sense switch,
connect the ignition sense lead to the accessory terminal from the ignition
switch (usually in the vehicle’s fuse panel under accessory or radio).
NOTE:
It is recommended to protect or isolate
the Module’s ignition sense input
from voltage spikes in excess of +/- 40VDC. Such spikes can be hundreds
of volts in amplitude and are common in larger vehicles (utility trucks, buses
and etc.), especially when the source is common to a solenoid coil. A
triggerable oscilloscope is required to determine the existence of such
spikes as most voltmeters cannot measure in short duration (< 1 msec). If
the condition of the intended ignition sense source is unknown, it is
recommended to isolate the source from the Module with a relay or the use
of a suppression diode wired between the source and ground. Any high
current suppression diode (i.e. MR2535) with a breakdown voltage of
between 18 and 40 volts will suffice. A suitable diode kit is available from
Motorola parts, kit number HLN6325_.
•
If it is required to have the radio power up
only via the control head’s on/off
switch, then connect the ignition sense lead directly to the positive terminal
of the battery. This will mean the ignition sense will always be ignored and
a re-wiring will be necessary in the future if the operator chooses any
ignition sense CPS setting.
5.2 Check Physical Installation of Module Ground and Wiring
•
Take care to scrape away paint on the chassis at the place where the
ground connection is to be made, and try to keep the ground lead as short
as possible.
•
Verify that the BATT+ lead (red) is connected directly to the positive
terminal of the battery and the ground lead (black) is connected to the
vehicle’s chassis using as short of a length of wire as is practical.
•
For vehicles that have other types of electronic equipment installed (lights,
flashers, computers siren/PA and etc.), use a separate ground for the
Module.
•
Make sure that the mobile radio antenna is the minimum required distance
(three feet) from all devices to prevent radio frequency interference (RFI)
from interfering with the Module or connected devices.
