So this forum has been great, longtime reader, first time poster. A few weeks ago the AC in my 2003 Civic LX (stickshift) started to get spotty, and I read on here that I should try swapping the horn relay with it to see - and that did the trick. So I got a new one and we were back up and running, no problem.

Today, the AC was blowing warm air, so I pulled over and tried swapping out relays but didn't work. So I took a piece of wire and bypassed the AC relay completely, and then the AC started working again. I figured I'd hardwire it for the ride home since it's like 100 degrees out. I had about a 40-minute ride home, and the AC was nice and cold. I was going to go home, get out the voltmeter and see if the DC ins on the relay were getting juice when the AC button in the cabin was 'on.' I did notice that each time I'd throw the car into neutral as I approached a stop sign or red light, the car would stall out, which was different than normal - usually when the AC is on I can throw the car in neutral while rolling and the car won't stall out. I just feathered the gas, though, figuring it was a temporary problem until I solved the electrical problem.

I stopped off at a buddy's house to drop something off, and left the car and the AC running. I'd gotten about 20 feet from the car when I heard a noise that sounded like a trombone (2 seconds in duration), then a crapload of steam from the area of the right-front tire... 1 second of silence, then the noise and steam again... and by this time I'd ran back the car and pulled the hood open and removed the wire that I was using to keep the AC running.

I'm assuming that this is going to be a pain in the *** to fix. I've never troubleshot an AC system further than bypassing relays but I've got a jack and jack stands and don't mind learning if someone can point me in the right direction. I'm thinking I blew a line or a seal somewhere, that maybe the electrical system in the Civic is sophisticated enough to moderate the usage of the AC system while the car is rolling so that it's not always on, and by me leaving it engaged solid for 40 minutes, there was some blowout.

 

That's what it sounds like. The pressure switch was probably preventing the A/C system from working, and you bypassing it caused problems.

Honestly, I'd take it to a professional.

 

That's what was wrong with mine. Cost me less than $100 at the dealer to get it vacced and charged. They also added dye penetrant in case there was a major leak, but it's been good for months now.