86 300 e
in order to activate compressor clutch I have hot wired it to the fuse box (always on)
I have the correct charge in the system
I have continuity through the preasure switch
The normal system is sending 6 volts to the preasure switch (not enough to opperate the clutch)
the system of course does not cycle with this set up
with the hot wire disconected the system will work sporadically.
any help would be greatly appreciated
thanks
bill

If it is short cycling with the jumper removed it sounds like it's under charged.

I would not recommend jumpering this system. The pressure switches serve to protect the system from under or over charge damage.

Good luck,

You need to have the pressures checked. This will tell you where to start looking next. If pressures and charge are OK, I would bet on the binary cutout switch on the receiver/dryer.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

I'm having trouble with my compressor not coming on too ('88 260E). There are two pressure switches on the receiver/drier one has 4" leads with a green plastic body and the other is larger with spade lugs on it. I assume one is the high/low cutout and the other is for the aux fan. Which is which?

Thanks!

The switch with the leads is for the fan. The other is for pressures.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

Here is a schematic of your system. The compressor clutch is controlled by a smart relay. One of the inputs to the relay is probably has a problem or the relay itself is bad. Check the imputs - things like engine speed input, overheat input etc.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Thanks Dave,

The schematic is really what I needed. My repair manual does not have one.

I keep bidding on repair CD on ebay and always get outbid. It's very frustrating sometimes.

- John