Cadillac Repair: A/C 10 A fuse blown, amp fuse, seville sts

Question
92 Seville STS
A/C works great other than burning out the 10 Amp fuse. Coolant sytem was converted to 134 several years ago. Had no problem since. 140k
put gauges on system and plenty of refrig on board.
system is cooling at 40 degrees.
replace the 10 amp fuse.
Run auto on highway about 10 mins and it burns out.


Answer
Hi Norman, Check a wiring diagram to make sure that the compressor clutch is the only thing on that fuse. By unplugging the compressor and turning the a/c on that should test the rest of the circuit. If the fuse doesn't blow then the clutch coil is drawing too many amps while running and needs to be replaced or the anti spikeing diode in the clutch wireing harness is starting to fail. Otherwise you will need to unplug things on that circuit until the fuse doesn't blow anymore. You could power up just the compressor clutch with a jumper wire and an ampmeter to test for amperage draw. If it aproaches 10 amps then its time to replace the clutch coil or the compressor. Make sure to fuse the ampmeter with a 10a fuse so you don't damage your meter unless you have an inductive clamp meter to use. Hope that helps. Bill