TROUBLE SHOOTING SECTION
COUSTIC.COM
SYMPTOM
1. No power
2.Power without sound with red power/protect indicator on
3.Power without sound with red power indicator on
4.Very low sound from both radio & tape
5.Frequent automatic amplifier shut down
6."Motorboating": The amplifier power indicator going off repeatedly when the audio system is on
7.Whining noise when engine is running with noise varying with the accelerator (noise level varies with source unit volume control)
PROBABLE CAUSE
Check connections to the amplifier's Ground, B+ and Remote terminals. Check connection at "+" terminal of the battery. Check the remote
Check the voltage at the amplifier, and the remote ON/OFF lead. The voltage should measure between 11 V - 15 V. If the measurement is beyond this range, have the source unit checked out by an authorized dealer.
Turn the amplifier off, and Check all input & output signal cables and connections. Check the speakers for short with a VOM (volt meter) or by connecting them to another audio system. After making sure everything is normal, turn the ampli- fier on again.
The continuous red light of the power indicator signals a high internal operating temperature, which results in the amplifier switching off temporarily; when the amplifier cools down to a safe level, the amp will automatically restart.
Check your source unit’s fader control.
Check the amplifier's Input Sensitivity Level.
This indicates that the amplifier is operating at a continually undesirable high internal temperature. High operating temper- ature caused by inadequate ventilation: refer to the
High operating temperature caused by an excessively low impedance load, say below 2 ohms: check for bad speakers and/or electronic crossover, proper passive crossover compo- nents; if all else fails, try rewiring the entire system.
High operating temperature can be caused by an incorrect input sensitivity level: refer to
Check the amplifier's connection to the battery. Check battery voltage. If low, recharge or replace battery. Check all ground connections.
Reroute power cable from battery to source unit directly, bypassing the battery terminal in the fuse box. Check power connections to be sure they areclean. Check ground connections to be sure the ground wire is in direct contact with the bare metal surface of the chassis (with that spot scraped clean of any paint, rust or grease).
SYMPTOM
8.Constant level whining noise (most noise with source unit volume at minimum)
CAUTION:
9.Radiated noise: crackling noise on FM which is not present when playing tape or CD (noise varying slightly with accelerator but is present at all times)
PROBABLE CAUSE
Check for a ground loop in the system. Turn the system off and,
Do not disconnect the power amplifier's ground when the system is on. This could damage the amplifier.
Check for defective signal cables. Disconnect signal cables at the amplifier and listen carefully for noise. If the noise dis- appears, run a test pair of signal cables. If there is no unde- sirable whining noise, reconnect to the amplifier with the new pair of signal cables. Check battery ground connection to the vehicle chassis to make sure it is tight and clean. Check battery negative terminal connection to make sure it is tight and clean.
Check if the noise is actually radiated noise: tune a portable radio to the same FM station. Move the portable radio close to the vehicle engine. If crackling noise comes from the portable radio, then the noise you have in your vehicle audio system is radiated noise. Check with a VOM (volt meter) to makesure the antenna is really grounded to the vehicle chassis.
To ensure a true ground, break the plastic covering of the antenna lead and solder a piece of heavy wire (minimum
14 gauge) to the braided shield. Ground the other end of the wire at the same point as the radio ground.
Check spark plug wires. They should be
Make sure engine block is grounded to the vehicle chassis at a bare metal spot (scraped clean of paint, rust and grease).
Make sure hood is also grounded. If not, use a ground strap (which is available from any auto parts store) to ground the hood to the vehicle chassis.
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