Working on a 09 BB RE Cat C-7 school bus. The noise suppression switch on the bus quit working and the a/c and radio stay on constantly even when the key is in off position. Changed solenoids to no avail. Solenoids do make clicking noise when suppression switch is pushed. I have to take off negatives to battery so it will not drain overnight. Recently we had to have those child safety buzzers installed per California state law and that is when problem started. Any answers appreciated.
When you push the noise suppression switch does it turn those things off? Also, when the key is off do you have voltage to the signal side of the solenoid? I'm wondering if you are getting a feed back from your child check. If the child check is like the ones I use, you have to have power to it all the time to turn the dome lights one when you turn off he ignition. Then when the button is pressed in the back and the door is open the system turns off the dome lights. So, if they tied into your noise suppression solenoid that might be the issue. Just a thought.
Well, Bus magically fixed itself. Called out folks who installed child check. Went to show them what the problem was. And, POOF Bus was working perfectly. Installers looked at me like What is wrong with you man! LOL. They had to come out anyway to fix some other things that were wrong with the child check systems. But Im thinking maybe a relay or solenoid was stuck in the back of the bus. Have to like those problems that fix themselves.