Motorola CDM 1250 Strange Issue

[ahaight]

Hello!!

I have a Motorola CDM 1250 in my car and I've got to say, it's doing a really good job with GMRS Rx and Tx, and scanning local channels. But I have a strange issue, I can transmit just fine on GMRS (465mhz) but if I try another range (453-455) it does the chirp for low voltage. It's set for 20 watts on low power (after changing the settings on CPS). I am NOT wired directly into my car, I'm using the cigarette lighter port and bought a cable that is cigarette port, to cdm 1250 end. I'm assuming it's not letting me because the cigarette lighter wires in my dashboard are long, and are a smaller wire gauge, causing the drop due to a decent draw. Rarely If i put my foot on the accelerator while in park it will work, but stop when i take my foot off. It's very strange.

 

[ff026]

Yeah your drawing to much current from the lighter plug. The main power needs to go to the battery and you need to use the ignition kit and reprogram the radio for ignition.

The cigarette plug doesn’t have enough current to power the radio on Tx.

 

[nokones]

Also, some Motorola radios require grounding to the chassis and not directly to the battery. You may want to research and see if that is a requirement for the CDM series radio by checking the maintenance/installation manual.

 

[mmckenna]

I've never heard a CDM beep for low battery. Are you sure it wasn't rebooting?

Do yourself a favor, wire the positive direct to the battery and the run the negative to a ground under the dash. You'll save yourself a lot of headaches. Cigarette lighter sockets are for cigarette lighters. Spring loaded contacts don't make for good radio power.

 

[ff026]

I've never heard a CDM beep for low battery. Are you sure it wasn't rebooting?

Do yourself a favor, wire the positive direct to the battery and the run the negative to a ground under the dash. You'll save yourself a lot of headaches. Cigarette lighter sockets are for cigarette lighters. Spring loaded contacts don't make for good radio power.

Wouldn’t believe it till it happened to me. Long story short. Chiefs car parked in a driveway on an incline. I’m working the fire for a good 45 minutes. Everything gets wrapped up. Using the CDM in the rear of the car I get the low battery sound like the waris portables. I don’t think twice. Take off the gear get in the drivers side, bang engine is off. Hmmm. Oh crap I’m on a hill. Get a jump move the car all good. Never heard the beep again.

 

[ten13]

The cigarette plug doesn’t have enough current to power the radio on Tx.

Not necessarily so.

My car has a 120 watt cigarette lighter socket. When I first got the car, I sat my 1250 on the seat next to me, initially for receive only. One day, I accidentally keyed up the mic, and the fuse didn't blow on the socket. I think the amps for what is now called the "accessory socket" is 15 amps. I continued operating like that, transmit and receive, using a lighter cord into the 1250 for a few months until I got the radio properly installed.

A lot of newer cars have high-wattage lighter sockets today.

Maybe the OP's "noise" is, in fact, the radio rebooting, but why, I don't know.

 

[nokones]

Maybe the OP's "noise" is, in fact, the radio rebooting, but why, I don't know.

When the radio drops below the designed threshold set for low power the radio will automatically shut down as a protection to the radio to prevent the brownout effect. After the radio drops out, the radio will sense the power level above the designed low power threshold, thus the radio powers up again, just like someone turned on the radio, and what you are hearing is the "Power-up Self Test Alert Tone" feature which is a CPS setting located in the "Radio Wide" Section/Page under the "Alert Tones". If you unchecked that feature box I bet you a dollar and a donut that you will no longer hear the beep.