Motorola ASTRO APX O2 User Manual

Chapter 7 Best Practices: Installation & Troubleshooting
In this section are Motorola recommended vehicle installation practices that can address or prevent
many issues, including:
• Radio circuit damage due to over voltage condition
• Radio/Accessories "lock up"
• Radio/Accessories change state/lock-up when radio PTT is depressed
• Radio powers up in the FL 01/90 state (general communication error code)
• Radio intermittently resets
• Radio loses secure key
• Transmit audio distortion on motorcycle radio when engine is running
• Keypad buttons become inoperative for motorcycle radios when engine is running
• Alternator whine present when transmitting with engine running
• Radio/Accessories turn themselves on/off
7.1 Check Wiring of Ignition and Radio Ignition Sensing
• If it is required to turn the radio on and off via the ignition sense switch, in addition to the control
head’s on/off 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: Motorola recommends protecting or isolating the radio’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, Motorola recommends isolating the source from the radio 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.

Motorola ASTRO APX O2 Specifications

General

Brand	Motorola
Model	ASTRO APX O2
Category	Radio
Language	English