I'm trying to get the a/c functioning in my '88 GL d/r with the Hitachi system; so far I've replaced the pulser, pulse amplifier, both relays, and the microswitch with what are assumed to be good units from a '94 Loyale carcass. System still has R-12 in it, pressures unknown until I can get a shop to check that. Still not getting the compressor clutch to engage.

 

Would be very helpful to have the relevant section of an FSM to troubleshoot with, the Haynes and Chilton manuals are next to useless for air-con. And I know it's not a 'necessity' but we are already getting average temps of 90+ here along the Front Range, it would be nice to be able to blast the hot air out of the wagon after I get in it.

You can kind of check your pressure yourself. It's not exact, but you can hot wire the compressor and see if you get cols air. I believe it's the blue wire on the compressor. Apply 12v and it should kick on. if it doesn't, either the clutch is bad or the ground is. Once it kicks on, you should get cold air within a minute. If not, charge is low. There's also a fuse to the AC relay that may or may not be there. It's listed as optional. Also, if the high/low pressure switch on the accumulator line is bad, it won't kick on.

I grounded the red/black wire at the a/c relay per something I found online and the compressor kicks on. So according to what I read there is a fault in the stupid pulser system. I don't think it's that, I'm leaning towards either low pressure in the system or a bad trinary switch. I'll bypass the pulser coil at the pulse amp today so I can sit in-car with it running and see how cold it gets.

My '88 wiring manual doesn't show a lot of detail for the AC system for some unknown reason. The slip amplifier which turns on the compressor relay has a input from the minus side of the coil, the AC cut relay (which supplies a path to power for cars with AT transmissions), and a switched ground path through a thermostat contact switch. I don't have any info showing the wire colors.

Leaning more strongly towards low R-12 charge; after bypassing and running for about 10 minutes, the air from the vents wasn't cold and there were bubbles in the air dryer sight glass the whole time. Need to find some R-12....

Any word on what ever happened with your a/c smashedglass?

 

I'm trying to get my A/C working as well, my compressor clutch is not engaging.

 

When I got the car, hitting the a/c button would do absolutely nothing at all, not change in RPMS, or anything

 

I got one of those conversion kits and when I started filling it up with the a/c on, the engine kicked up it's RPMS on it's own, but then lowered em' back down.

 

Now when I turn the a/c on the engine rpms go up for about 5 seconds, and then it drops back down. It will repeat this each time I hit the button from off to on.

 

The compressor clutch does not engage through this entire process.

 

Any advice? Was your system just low on pressure?

 

Sorry to semi-threadjack, I'm in the same boat though; It's HOT out

No, haven't had a chance to dig any further yet.