Help with GM300 16pin +12v Ignition Sense Cable

/\/\oto /\/\edic · Post by **/\/\oto /\/\edic** » Tue Apr 11, 2006 12:08 pm

I have a GM300 that I am trying to connect the 16pin with the orange 12v ignition cable and am having problems. The radio is connected to a constant ground and +12v source. However, the radio stays on all the time no matter if I have the 16pin connected in the back or not. Is there a jumper or a setting in the programming I need to set for this to only power up when +12v is connected to the remote ignition wire?

Thanks in advance for the help!

William

kcbooboo · Post by **kcbooboo** » Tue Apr 11, 2006 12:26 pm

Nope. The power switch on the back of the volume control removes almost all power to the radio.

The switch could be bad and stuck on all the time.

Someone could have jumpered the switch so the radio stays on all the time.

Someone could have added a wire inside the radio to bypass the front panel switch, thus keeping the radio on all the time.

The original pot/switch is no longer available. A replacement part which is a bit shorter than the original can be made to fit. There's an article about it in the Motorola/MaxTrac section of http://www.repeater-builder.com that describes how to modify the volume control circuit board to accept the replacement switch, if you need a new one.

Bob M.

Lake Effect · Post by **Lake Effect** » Tue Apr 11, 2006 12:37 pm

There is a pico fuse inside the radio near the 16 pin connector that must be removed for ignition control.

L.E.

kcbooboo · Post by **kcbooboo** » Tue Apr 11, 2006 1:05 pm

Sorry. I might have mis-read the question the first time and not fully understood the problem.

Yes, the pico-fuse inside the radio needs to be removed to enable ignition control. Then you need to feed +12V into the ignition control wire to allow the radio to operate.

Bob M.

/\/\oto /\/\edic · Post by **/\/\oto /\/\edic** » Tue Apr 11, 2006 1:55 pm

Can you give me a description of what the fuse looks like or even a picture? I want to make sure I pull the right fuse when I open it up.

Thanks!

kcbooboo · Post by **kcbooboo** » Tue Apr 11, 2006 2:16 pm

The fuse is probably the size of a 1/4 watt resistor. Usually they're a shiny green color. The easiest thing to do is cut one lead in half, then pry the fuse up off the board slightly. That way, it's easy to repair in the future.

The location depends on the type of logic board you have. This will be the board under the bottom of the radio.

Hope this helps.

Bob M.

/\/\oto /\/\edic · Post by **/\/\oto /\/\edic** » Tue Apr 11, 2006 2:22 pm

Thank You!

Jay G. · Post by **Jay G.** » Tue Apr 11, 2006 2:46 pm

another way of doing it if you cant locate the fuse is only give the radio a ground from the main power lead, and using the 16 pin conn power the radio, then key up - it will pop that fuse and then it will work.

jackhackett · Post by **jackhackett** » Tue Apr 11, 2006 7:00 pm

Did they not use a surface mount fuse in some of the later model GM300s, or am I thinking of a different radio? If they did it would be a little clear plastic rectangular thingie right near the 16 pin jack.

Post by **wavetar** » Wed Apr 12, 2006 3:41 am

jackhackett wrote:Did they not use a surface mount fuse in some of the later model GM300s, or am I thinking of a different radio? If they did it would be a little clear plastic rectangular thingie right near the 16 pin jack.

I've never seen it in a GM300...I'm trying to think of a mobile model with a surface mount fuse, but none are coming to mind at the moment.

Todd