67Dart273
Well-Known Member
Heh.........I admit the headline was to get your attention. This morning, started to finish the engine conversion in the White Whale III to add an A/C compressor
Went through the "pile," and I've lost count. Two were earlier TBI era compressors.....completely different mount and hookup. One both clutch and compressor are completely frozen. One turns but "grates." The last two THE CLUTCHES TESTED SHORTED..........which brings me to........
How NOT to blow up your A/C compressor clutch!!!!
It turns out that (at least on the later Dodge RAM/ Dakota/Durango) that there is a spike protection diode IN THE PIGTAIL of the compressor. If you TRY TO BENCH TEST this by hooking 12V to the clutch, AND IF you get the battery polarity incorrect, YOU WILL SHORT that diode, and "easy to assume" the clutch is "bad."
(A normal clutch reads upwards of 3+---4 ohms. A shorted diode reads a fraction of an ohm.........)
But I'm suspicious. So I cut the pigtail in half, pulled the protection sleeve off, and........................
(Cutting the pigtail............I would not have done this except this will be "underdash" hang on NON OEM air. So the original harness connector will not be used)
Went through the "pile," and I've lost count. Two were earlier TBI era compressors.....completely different mount and hookup. One both clutch and compressor are completely frozen. One turns but "grates." The last two THE CLUTCHES TESTED SHORTED..........which brings me to........
How NOT to blow up your A/C compressor clutch!!!!
It turns out that (at least on the later Dodge RAM/ Dakota/Durango) that there is a spike protection diode IN THE PIGTAIL of the compressor. If you TRY TO BENCH TEST this by hooking 12V to the clutch, AND IF you get the battery polarity incorrect, YOU WILL SHORT that diode, and "easy to assume" the clutch is "bad."
(A normal clutch reads upwards of 3+---4 ohms. A shorted diode reads a fraction of an ohm.........)
But I'm suspicious. So I cut the pigtail in half, pulled the protection sleeve off, and........................
(Cutting the pigtail............I would not have done this except this will be "underdash" hang on NON OEM air. So the original harness connector will not be used)