Smart Siren Problem

[radioinst]

Does anyone have experience with a smart siren head that seems to get warm and start flashing the lights in the head and on the car? If I put another head in it's fine for awhile and then acts up again. The car is running and it does take about 20 minutes for it to act up. I'm going to check voltages and see if something is wrong there first.

[radioinst]

I checked voltages coming out of the smart siren box using a modular wall jack and without the head attached. Using the colors of the modular wall jack car engine off: Black Ground, Yellow 12.5v, Red .5v, Green 10.8v. Then I started the car and got : Black Ground, Yellow 14.3v, Red .5v, Green 12.7v. Are these normal? I checked another car and they were all pretty close.

[radioinst]

I looked inside the head and found 2 rma sickers where the head has been sent to federal signal for repair twice before, i'm installing a spare that has never been sent in and will see what happens.

[ka8ypy]

I checked voltages coming out of the smart siren box using a modular wall jack and without the head attached. Using the colors of the modular wall jack car engine off: Black Ground, Yellow 12.5v, Red .5v, Green 10.8v. Then I started the car and got : Black Ground, Yellow 14.3v, Red .5v, Green 12.7v. Are these normal? I checked another car and they were all pretty close.

Those voltages would be correct, sounds like a bad head.

[radioinst]

it was the head, it hasn't messed up again since it was changed.