Batboard

I'm getting a "chirping" sound from my CDM 1250 when the car's ignition is in the "Accessory" mode (engine not running) and I hit the PTT. Power output of radio is set at 45 watts. Still transmits and receives normally.

Could this sound indicate an insufficient power source? Sounds like something when a radio is connected to a too-small power supply.

Something to look for in the software, or a car "problem"?

Thanks!

First silly question: what is your battery voltage in that state? Could your battery be weak?

The chirping noise is due to the voltage drop the load your radio is putting on your electrical system.

The voltmeter is your friend.

From prior experience, I sort of realized it could be a car battery problem, but wanted to check (although I've seen nothing to indicate...yet...that the battery is weak).

I will check further.

Thanks to all....

Main power line going directly to the battery and fuse good ? (I had some odd behavior from a Spectra that had it's main B+ line disconnected and ignition sense line was powering up the radio).

When checking the voltage, put your probes directly on the power connector on the back of the radio 9just back out the plug a bit to be able to connect your probes) as you want to see what voltage your radio is seeing. Checking the voltage at the source or from positive to chassis won't show you a poor/high impedance power cable.

One of the indications of a poor battery is the radio clock will reset to 12:00 when you start the engine. Another is the engine is cranking slow. But you also could have an alternator that isn't charging the battery correctly when the engine is running.

Time to pull out the digital volt meter and do some checking.

Jim

...just wait till the voltage drops low enough, and the CDM turns on in the middle of the night and freezes.

thebigphish wrote:...just wait till the voltage drops low enough, and the CDM turns on in the middle of the night and freezes.

and sucks your car's battery inside out!