Low air alarm

here's the question, what are all the sensors connected to the low air alarm?

 

Symptoms: only when my vehicle is in motion do I get the 'low air' alarm by itself. When I pump down, rightly do I get both a 'low air' warning light & alarm, so that tells me that the low pressure switch is not bad.I just checked with Freightliner parts and they confirmed there is no sensor on the parking brake valve(s), as one gentleman told me that I would get that same alarm if I tried moving the truck with the parking brake set. If so, where is that sensor? that's the sensor that's bad. Anybody?

 

Update.
I have a brother in law that's worked for cat as a mechanic for years. After bouncing ideas off of him he said that it sounds like a bad parking switch... if the parking break is on and you try to move the truck, the low air alarm will sound. I'll give that a shot and see how I come out.

 

Hey, anybody know the location of that air junction manifold on an 04 Columbia?
I've been told there are about 5 different sensors on it, and that's where ill be finding the pressure switch & park brake switch.
Anybody? Thanks

 

Having a similar problem, only the low air buzzer stays on all the time. I have a 2007 freightliner Columbia

 

Similar to who's problem? There's a few odds & ends here that kinda all regard the same thing...
that's why I made sure I updated all that I did - to help out.
what say you? What are your symptoms?

 

Pardon me, I thought you had a problem with the low air buzzer going off, I must have read the post wrong.

 

No, I completely had. But J, you're replying to this whole thread of this forum, and there a few different problems that others are bringing to the table, and I'm sure none of us know who you are referring to. I guess you're probably experiencing the same symptoms I had. I shared everything I did To fix it. Lemme know if you have any questions and I'll see if i can help.

 

.... update 9/18/15
I found that manifold - I did forget to update. The manifold is behind the trash can. It's fairly easy to get to. Start by popping up the cup holder. There, you will find some torque head screws, T20 I think. Like I said, it's pretty easy to get to. Once you move the trash can housing, just look up there to see all the plumbing coming into the junction.
I had to replace the very park break switch, because it started leaking.
Go to Napa autoparts and get a sensor switch socket. That's the only way to replace those switches without potentially damaging them.