PM1500 RANDOM TX KEY UP WHEN OFF NOW WHEN ON

[kb9suy]

Installed a motorola dual head vhf pm1500 radio about a year ago in a fire engine. Has been working just fine up until a few weeks ago when the rig was off it randomly started transmitting intermitently rapidly. Due to the engine having a mdc id we were able to quickly figure out what rig it was. The radio has power to it all the time and using ignition leads to turn the radio on and off. So knowing mother M and excellent engineering I decided to dump some newer firmware in the radio. Radio worked fine for two weeks now it keys up when the radio is powered on!!!! Anyone having the same problem I am having with the pm1500 or xtl line?

[nrembis]

is it still transmitting with out the mics attached to each head?

[kb9suy]

No I haven't tried that yet. Just made sure they weren't being bumped or anything.

[com501]

Take the mics off. If it persists, take the radio or heads apart and look for water damage. If it stops, change the mikes (probably water).

I can't tell you how many times we have had radios douched and the fire fighters had 'no idea' the radio got wet.....