(Another) Electrical short -- A/C

[ThreeQuarter]

There's a problem with the factory A/C system in my friend's '68. When I turn it on, the whole system shuts down, like it blew a fuse (blower motor, compressor clutch, everything just turns off). And I can switch it on and off after that and it's just dead. But I can unhook the battery and hook it back up, and then when I turn the system on I get the quick burst of electricity and then the "blown fuse" type thing again. Is there some kind of breaker that can be thrown in this system? I eralize it has a short some where but I am curious of how it resets.

I'm clueless on this one, and don't need to be tearing into the A/C electricals. Thanks in advance for any help.