Rep Power: 0

A few weeks ago my ac in my car started blowing warm. I noticed the radiator fans still came on but the clutch on my ac wasn't engaging. Just in case I replaced the AC relay. I also ordered a new an clutch and installed it. After installing, it started blowing cold again for a good 40 min then stopped engaging again. I can't get it to come back on, even after tapping it with a wrench.

Any ideas what else it could be?

 
Rep Power: 211

Just tap it in...tappitty, tap,tap.

With engine running and the a/c set to "on" use a piece of 1"x 1" wood or similar to tap on the a/c clutch to see if it closes the air gap (between clutch and coil) to hopefully cause it to engage. If that's the issue the air-gap needs to be tightened back to spec.

Too much or too little freon can cause the compressor to not to engage as well. Use proper HVAC gauges to check and not those shitty freon cans with a gauge sold in auto parts stores.

 
Rep Power: 0

I gapped it to spec using a feeler gauge. And I've tried telling with a wrench while it's running. I can check it though

 
Rep Power: 211

I should improve my reading comprehension...you already tried tapping it (first post).

I had a similar issue with an '07 Mazda 3 and it turned out to be (IIRC) the high side expansion valve. I'm not that skilled with HVAC and that was a local mechanic who found and replaced the expansion valve.