----- Original Message ----- From: "Jim Cathey" <[EMAIL PROTECTED]>
Thanks Jim, I wrote: >> The fan motor has three leads so I suspected it is a typical >> three speed motor setup You wrote: > Probably two speeds with only three leads. Such motors don't > need capacitors for starting or running as they don't start > under load. My understanding is that they're usually just > shaded-pole motors, but those aren't as efficient. It's > possible that the efficiency drive has even gotten to the > blower motor too. After cleaning off the crud I found three more leads (6 total) coming from the fan and a diagram which showed a capacitor between two of them. >> The compressor also has three leads and a (common?) lead comes in >> through a separate thermal switch . >> The part I find confusing is a big capacitor which has three leads and >> a rating of both 7.5 mfd and 35 mfd. > Sounds like the compressor is cap-start and cap-run. You should be > able to trace the circuitry enough to figure out where this (important) > capacitor goes. The rest of the electronics is just crap and can > be replaced by a switch or two, as you surmise. > >> ... they may require some sort of hookups with the capacitor. > > They do. But just trace the wiring, you'll get close enough. > The command and control stuff is small and fiddly, but the big > power paths are usually still easy to map out. Tried tracing the wiring through the stacked pc boards where all the wires terminate. These pc boards have a transformer, 5 capacitors, four relays, four transistors, four dimms, 24 diodes, and 51 resistors! While the wires to the compressor and fan terminate at the relays, haven't been able to figure out which connects to which since the relays are sealed. Since the fan motor has such a strong smell of burnt wiring and since the scarce replacement capacitor is so expensive, I've decided to junk it and get a new one. I would like to rig up the compressor as a vacuum pump if it's still good and run it with a 35 mfd capacitor. I would guess that the capacitor would be wired between two of the three leads on the compressor? >> One thing I've been curious about is the kind of compressors these >> newer A/Cs have. They are long, narrow compressors; much smaller than >> the old type. I would guess they would be "rotary screw" compressors on >> the >> order of the large ones in big commercial installations. The Sharp makes >> a >> very steady "tone" comparable to the large commercial compressors steady >> "roar". > Scroll/roll type? > -- Jim ----------------------------------------- Looked that up on the 'net. You're right. Seems like only the big ones are called "screw" compressors. Gerry _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
