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Wayne, Journeyman
Category: Heavy Equipment
Satisfied Customers: 9620
Experience:  34 years experiance as engine rebuild and problems.Thermo-King repair and trouble shooting.
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Low Air Pressure Warning Buzzer Not Working

This answer was rated:

Low Air Pressure Warning Buzzer Not Working
Hi I'm Wayne,
I will help you with this,
Good evening
did you check your low air pressure switch ,
this will not go off , unless tripped by the sensor
let me know
Customer: replied 5 years ago.
No. where is this switch?
That was quick......

Its 3 different places
On compressor line 1 wire ,
on fire wall drivers side same 1 wire
or in dash in the air manifold

If this helps you, Please hit Accept, as this is the only way I get Paid
if not get back to me
Customer: replied 5 years ago.
Is this info specific to my model or "in general"?

(wasnt there chat button on here someplace?)
Yes it went from chat to Q & A , due to time

This is specific, they kept changing it
if you go to dealer and ask , they would look it up and tell you 3 places

I am here and will answer as fast as I can Type , which is , no record
Customer: replied 5 years ago.
do you perhaps have any diagrams or schematics?

you see....both terminals on the buzzer are "high" (hot) One is supposed to be...its the B+ terminal but the other terminals (which say Slow and FAST) im assuming one or the other are supposed to be grounded. The other terminal is at 12V as well. So as you can buzz. Now this is when the pressure gauge is reading below 60psi. Nothing changes when it increases beyond 60psi. So I just have a buzzer that is not buzzing.
that is the low air pressure sensor not completing circuit
,Sorry I do not have diagram, but you really don;t need then that
just locate the low air pressure sensor, and replace
to verify that it is bad take wire from switch, and ground it , the buzzer will go off

Customer: replied 5 years ago.
What I need is something to go on.... I am not "near" the truck right now.
and I wont be until the morning. If anything is amiss I might have an additional
question with regard to this issue. So if you even have a part number
I can perhaps look it up and see what this pressure sensor looks like
so I can find it easier. And by the way......when you said pressure "SWITCH"
you are using the terms SENSOR/SWITCH interchangablly correct?
Yes sensor / switch , same thing

Let me see if I can get Part #

Customer: replied 5 years ago.
I stand corrected they are 2 wire now
here is a site P/N and Pic
Customer: replied 5 years ago.
Ok ...
Im going to glance at it at 8am...
We are getting close...if no ambiguities
crop up...Ill Accept when I log back in.
Sounds good to me
But you will find that is your problem, very common

Wayne and 2 other Heavy Equipment Specialists are ready to help you
Customer: replied 5 years ago.
Thank You