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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: statedrive on April 06, 2008, 09:15:14 AM

Title: MAC switch on 1989 Liberty
Post by: statedrive on April 06, 2008, 09:15:14 AM
Recently I bought a 1989 Liberty Prevost...I cant find any info on the MAC switch.....also the 12 volt pancake air compressor runs up to pressure, however I cant use the leveling sys on the manual position...any help out there.......thanks   Dave
Title: Re: MAC switch on 1989 Liberty
Post by: Sammy on April 06, 2008, 09:22:20 AM
What is a MAC switch?
I have worked on H3 40's,41's and 45's and will try to help, if possible.  8)
Title: Re: MAC switch on 1989 Liberty
Post by: edroelle on April 06, 2008, 09:25:56 AM
Dave,

With some Prevosts, you need to have your key in the ON position for power to go to the leveling valves to operate.  I am not sure if Liberty changed that.

Ed Roelle
Flint, MI
Title: Re: MAC switch on 1989 Liberty
Post by: statedrive on April 06, 2008, 09:28:35 AM
Im not sure what the switch does...it a rocker switch with the letters MAC........I think I read that it may have something to do with the leveling sys when the ign key is off....when I push it (spring loaded to return to off) the lights seem to dim a little so I dont want to short anything...thanks  dave
Title: Re: MAC switch on 1989 Liberty
Post by: Dallas on April 06, 2008, 02:16:05 PM
If you give us a year, serial number and model, we may be able to help.

I'm learning that Prevost has a different wiring diagram for each bus and each variation of that bus that they made.

I doubt that Liberty messed with the original wiring on the dash, too much, but they may have.

One close thought, could that mean "MAX A/C?" Dunno, but if the lights dim when you flip it, it is drawing major power, could be the blower fans, condenser fans, evap. fans, or the draw from the compressor.

Or could this have come from Mike, the BBS owner, and if you don't make your payment on time.. he flips it while you aren't looking?

Just silly ideas.

Dallas
Title: Re: MAC switch on 1989 Liberty
Post by: Ray D on April 06, 2008, 02:52:38 PM
Have your serial # ready and go to  this site, you can download the repair manual, technical publications, wiring diagram, air diagrams and sometimes the operators manual.  It is really a good sight.  when you download the electrical diagrams, they are divided into sections and all pages to that section are there, you end up downloading more pages, but they are organized and it will be matched to your serial #.

http://technicalpublications.prevostparts.com/en/wiring.asp

Ray D