|
|
|
|
|
#1
04-29-2011, 08:45 AM
|
|||
|
|||
|
'96 S420 AC Clutch won't engage
I cannot get the AC compressor to engage on my '96 S420. There is sufficient 134 to call for clutch engagement. The problem is there is only 9 volts on the harness plug. This car doesn't have the same thermal circuit as '95 and older 140's. There is a 1.5 wire in the plug and a corresponding .5 wire at terminal 25 on the digital Control unit. Somewhere the amperage is increased to handle the clutch requirements. The wiring diagram only shows a connector at the bottom of the fuse box with the two wires mentioned above connected.
I can't imagine the skinny wire coming out of the control unit carrying enough current to engage the clutch solidly. Nowhere in the wiring diagram is the circuit going into and out of the base module where some heavy duty switching occurs. __________________
__________________
Joe Tripp Mercedes Club member since '76 Continuous Mercedes ownership since '64. '93 300SD 111,000 miles. Now has '99 E300 engine. '94 S350 77,000 miles '95 S350 148,000 miles. '96 S420 159,000 miles.With '99 606 Diesel. Sold '99 S600 one of 14 imported. Sold. '89 Bentley 8 40,000 mi. Sold 
|
|
#2
07-08-2011, 02:32 PM
|
||||
|
||||
|
[QUOTE=
I can't imagine the skinny wire coming out of the control unit carrying enough current to engage the clutch solidly. Nowhere in the wiring diagram is the circuit going into and out of the base module where some heavy duty switching occurs. __________________[/QUOTE] I have wondered the same thing !! The wire is so thin, yet it is expected to handle all the inrush current, and coming out of the base module.....  I would think there is a switching device somewhere (either electronic or a relay)
__________________
1999 Porsche 996 Carrera Convertible 1994 420E - SOLD 1986 300E - SOLD, what a car 609 Certified
|
 |
| Bookmarks |
|
|
Linear Mode
