Reviving an old thread because i'm now officially in the same boat. It's not the resistor pack because heater and blower work just fine.
1. Compressor not kicking on. Although, I have watched the pulley as someone pushed the AC button and it did try to engage and turn slowly a couple times.
2. Periodic cold air. Every once in a blue moon the AC will get cold for about a minute, then nothing.
What I've done so far to try and fix:
1. Replace the AC relay, no change.
2. Verified hot/cold flap is working correctly.
3. Checked wiring near relay and wiring to compressor. Looks OK.
4. Replaced AC compressor with a new unit. This was my latest Hail Mary and unfortunately after professionally charging with 1.25 lbs of r134 the compressor is still not engaging.
Previous owner history:
1. Car had a factory SC installed, AC stopped working after that.
2. Car was at the Lotus dealer to have AC repaired. Dealer found a "bad ground" in the engine bay and repaired it, but AC still did not work.
3. Dealer wanted to remove the front clam to further investigate, but previous owner declined going forward. What would they be searching for under the front clam more than what I've already checked? Wiring is my only thought.
I've been chatting with another member with a similar issue, but at least he is getting cold air at the blower...it's just not making it into the cabin. My compressor simply isn't coming on and there's no obvious reason.