Remote Head Problem

[aschenavar]

Hi folks, got a head scratcher here. The following issue is on a fire truck, utilizing an APX8500 remote dual head setup. We have an O2 head mounted to the pump panel. Install was done by contracted Moto Techs. The O2 remote head has stopped working. Will not power on with ignition, or manually without as we were able to do before. I swapped a known working O2 head onto it with nothing there. I then took the non-working O2 head and put it in a known working position on another 8500 remote location and it will not work there either. I have traced as much of the harness I can under the truck and into the cab with nothing out of the ordinary located. The guys said they took the apparatus down a very bumpy road the night before it was reported to have stopped working. Our setups apparently only use the red, black and yellow doesn't go to anything within the wiring harness of the power cable.

Is there anything else I am missing to check before I call up the techs? Also, the main deck for this radio has power as the interior radio that mirrors the remote head has power and works fine.

Thanks

 

[clbsquared]

I'm pretty sure the yellow should be connected as well.

 

[com501]

All three wires need to be connected on every control head. Have your radio shop inspect the head for a blown internal use.

 

[aschenavar]

I'm pretty sure the yellow should be connected as well.

I checked another truck with the same setup and found that yellow was not connected on that unit either.

 

[jeepsandradios]

Yellow is ignition. Needs to be hooked up.

Maybe try reviewing install manual ? APX INSTALL

 

[hakwye8518]

Yellow Doesn't need to be connected if they are using ignition sense off the brick (see page 50 of the install guide). You would need to check the fuse on the red lead that maybe why a working o2 head did not work in that position and also have the non working head checked by your service shop since it did not work in a location that previously had working o2 head.