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View Full Version : AC Not Working - 1997 240sx


steve_o1989
07-06-2011, 11:20 PM
Ok, so last year all of the sudden my AC stopped working. I didn't really care at the time because I wasn't driving the car too much. I decided I wanted to try to fix it so I started digging into it a little tonight.

First thing that I did was make sure the system was charged up, it was.

Next thing that I checked was the 2 fuses for the system, they are both good and there is sufficient voltage at the terminals.

I then decided to try and bridge terminals 3 and 5 on the AC Relay to see if it was kick in like that, it did. So I know that the system works.

I tested the relay to make sure it works, and it does. So now I know that the relay is not being triggered to close the circuit.

At this point I went and got my FSM to see what it would tell me. I got to the point of checking for voltage at terminal 1 on the AC relay to find that I am getting 4.25v. This should be the line running from the fuse panel in the cab, which is putting out 13.6v with the car running. So, I figured there is a short somewhere along the line. The harness running in my drivers side wheel well had been chewed up at one point from the car being slammed and I had repaired 3 wires. I tore all that apart looking for the green yellow wire coming off terminal 1 of the AC relay harness and find nothing. The wire is there, but it is not one of the three that were frayed last year.

So at this point I am not too sure what to do. I have 13.6v at terminals 5, and 2, 4.25 at 1, and obviously nothing at 3.

I am thinking that there is some short somewhere, I just don't know where. The terminals are not corroded, the harness has never been hacked, other than those 3 frayed wires, the fuse in that circuit is good, not corroded, reading 0 ohms across the blades.

Do you guys have any other ideas on what to check or look into? I really don't want to rip apart the harness looking for a short somewhere. I am trading the car, I just wanted to see if I could get the AC going for the guy before hand.

Vernal
07-07-2011, 12:25 AM
Trace the beginning of the wire to the relay and check where the 13.6 drops