Compressor Won't Kick In!!! - PeachParts Mercedes-Benz Forum

Paratroop · #1 05-03-2009, 01:32 PM

1986 560sl. Working on the AC now.Put in compressor,Klima control, ACC unit,drier,o rings on suction and delivery lines,4 o rings on compressor manifold,also,high/low switch,new fuse for compressor,tightened everything up,vacumned it down,stayed down,opened up 134 with UV let it go down the low side,can got cold heard it being sucked down.Started car turned on AC,compressor refused to kick in.Jumped the high/low switch NOTHING,DEF.NOTHING.Point me in the right direction.This is MAMA'S CAR and she getting on this ol Paratrooper Butt about the heat and to get this thing finished so she can drive it.Any help appreciated.!!!

Roncallo · #2 05-03-2009, 01:37 PM

Quote:

Originally Posted by Paratroop

Working on the AC now.Put in compressor,Klima control,drier,o rings on suction and delivery lines,4 o rings on compressor manifold,also,high/low switch,new fuse for compressor,tightened everything up,vacumned it down,stayed down,opened up 134 with UV let it go down the low side,can got cold heard it being sucked down.Started car turned on AC,compressor refused to kick in.Jumped the high/low switch OTHING,DEF.NOTHING.Point me in the right direction.This is MAMA'S CAR and she getting on this ol Paratrooper Butt about the heat and to get this thing finished so she can
drive it.Any help appreciated!!!

What model car and year please.

When you say Klima control. Do you mean compressor relay or push button assy. Push button assembly is the most troublesome unit in the 560SL.

Jerry Cohen · #3 05-03-2009, 01:51 PM

Pull the two wire electrical connector off the compressor and see if you have 12v there. If you do the clutch coil could be bad, or the air gap on the clutch could be too wide. Also,some models have a sensor that shuts down the compressor if it's speed isn't where it needs to be so the serpentine belt doesn't get fried. There might be a fusible link involved as well. Without knowing the model/year, it's just thinking out loud.

If you don't, we need to look at the past. Did it work before you changed the Klima, and fuse?

Paratroop · #4 05-03-2009, 03:16 PM

1986 560sl. I bought it a little over 2 yrs ago.Had 2 owners before me.PO #2 said he had it 5 yrs and never had it on.I checked it then and it had no freon.Just getting around to working on the AC now.I looked at the drier bottle and noticed that the fan aux fuse connection looked bad took
it apart and the ceramic outer shell fell apart and revealed a broken
connection.Would that keep the compressor from kicking on??

450slcguy · #5 05-03-2009, 03:20 PM

Vacuum leak would be a probable suspect if not an electrical issue.

Paratroop · #6 05-04-2009, 03:58 PM

Before turning in last night I went outside to the car and opened another
can of 134 and left it on the low side came back in and read for 3 hrs on
every thread I could find on AC.Got up this morning found the can about
1/4 full.Put on my guages low and behold I had pressure.Started the 560sl up with the air on and jumpered the high/low switch,low and behold the
compressor kicked in(It would not kick in yesterday no matter what I
did.)It started sucking down the 134.

I HAVE AIR!!!!YES GLORIOUS AIR!!!5 MINUTES LATER

**** NO AIR!!WTF

Then something clicked,

no,in my head.Of the 100's of post I read last night, I remember something about a 110/115 heat sensor next to the chain lift where the
water hose goes in.See Picture.I removed that and

GLORIOUS AIR AGAIN!!! 42 degrees at vents.I'll take that. MAMA WILL GET OFF THIS OL PARATROOPER'S BUTT FOR A WHILE.I am going to leave that thing off.I don't care what it does.