Have a 2007 EC460B excavator giving me some air conditioning issues. When I try and turn the AC on it almost instantly blows the 20 amp fuse and the entire hvac display goes dead. I replaced the fuse and then unplugged the 2 wire connector that goes to the compressor clutch... Hvac display comes right back on and I can adjust everything like normal on it. While the machine was running and AC set to max, I went back by the compressor and plugged the connector back in... Compressor clutch never even attempted to engage and it instantly blew that 20 amp fuse again. If it safe to say I have a shorted out clutch? Any ideas appreciated!!
Good day Kevin I suggest you bridge the fuse with a multimeter and try disconnection of the components one by one, see which is giving the issue. Kind regards Uffex
Unfortunately, the schematics provided are for winter pre heating that never really took off here in America. Yes, based on your description, your clutch has most certainly failed. There is a quenching diode inside the clutch to prevent spikes when the field collapses. I suspect that it has failed short. Using an ohmmeter, clutch should show 18-20 ohms iirc. If you have a diode test setting, you should be forward biased for .5 to .8 volts and open circuit in the opposite direction. Good luck.
Thanks for the info! I called my Volvo dealer and they couldn't even find the AC compressor listed or a part number for it. They had to do some deeper looking and I guess it was listed somewhere under options. Complete compressor they said was 900ish and just the clutch itself was only like $50 cheaper... Odd. They said its now an updated compressor and requires a few other parts to make it work. Something he mentioned about a jumper harness or adapter of some sort? Not exactly sure. Did some Google searching and found apairinc.com shows they have 2 available, but says its only a 1 wire clutch? VOLVO EC460BLC EXCAVATOR Model Specifications Compressor Type R134 Refrigeration (lbs) Compressor Oil (oz) Compressor Oil Viscosity Sanden 2.65 lbs Compressors Condensers/Oil Coolers Evaporators Expansion Valves Heaters, Heater Cores Rec Driers/Accumulators Compressors Top of Page 509-6188 Original Sanden SD7H15, 5.4" 8 Groove Clutch, Direct Mount, WZ Head, 1 Wire 24 Volt 11104251 509-61883 Aftermarket Sanden SD7H15, 5.4" 8 Groove Clutch, Direct Mount, WZ Head, 1 Wire 24 Volt 11104251