CDM1250 TX Cuts Out

[sparky2842]

I recently installed a CDM 1250 in my Silverado. When I key the mic with the truck not running it cuts of tx and beeps like a ht1000 does when the battery is low. When the truck is running it talks fine with good audio reports. Is there a TX cut-off point when the voltage drops? The voltage does drop below 12 volts on key down. It cuts out so fast I cant get a good reading on my meter. The truck starts fine and I dont think theres a battery issue. I did run the wires right to the battery also.
Thanks in advance ,
Brian

[john9912]

Sounds like low voltage. The radio will make two short beeps similar to a portable when the voltage is low. Check your connections. If there is any corrosion, it will increase resistance. Check the voltage at the radio not just at the source. If you want to see quick changes in voltage, use an analog meter or the bar graph display on a good digital meter.

[sparky2842]

All contacts are clean and the voltage drops to 11.5v on transmit. I am going to have the battery checked, started a little slow this morning also.
Thanks for the help,
Brian

[tvsjr]

I have a suspicion your battery has dropped a cell... get it checked before you get stranded!

[Hightower]

Same thing happened here. The auto battery died a few weeks after.

Weird how the mobile gives the same low battery alert as the portables, but hey that's a good thing as it detects a defective auto battery.

Maybe they should use this as a selling point - "our radios alert you when your auto battery is failing"

[thebigphish]

Another goofy quirk of the CDM is the radio will come on, when set for IGN SENS, if the battery drops too low also. Seems counterproductive, i know, but we've had half a dozen different units that turned themselves on when the vehicle battery started to drop off. I've never been able to meter the truck battery when it has happened, but it's only happened on older batteries, and only on units which had their batteries replaced soon after from multiple jumpstarts.

[Hightower]

From what I remember, when the car voltage drops in the low 11's volt, the low batt chirp comes on.

[sparky2842]

Thanks everyone,
Picked up a new battery and cleaned up all the connections it works good now. Battery was tested and turned out to be bad. Got a larger amp battery to boot..
Brian