AC Problems

[nnkfws333]

I went to 240sx.org and did some research but I couldn't find much. Here is the situaition: When I do a lot of city driving (stop and go) on a hot day my AC will work but its not cold. Now if Im on the highway it works totally fine or if its kinda cool temp. outside, it works fine. I had a mechanic check my freon levels and he said I was full. I have no clue where to check next. I do have two electric fans in. The main one is blows air out while the AC switch fan pulls air in. Do you think not enough air is getting through? I also have the recirculating button pushed. Any help would be appreciated.

[DAEDALUS]

I had a mechanic check my freon levels and he said I was full.

How did he check it? Did he just measure the pressure? That would verify your compressor is working fine. If your car has the old stuff (freon, R-12), then the only way to really check the level is to pump it all out, weigh it, and then pump it back. I think for R-134a a pressure measurement is sufficient. The 2 fans you have...one is in front of the condenser, and one is behind it?

[nnkfws333]

Well....I have the old R12 and he hooked up a machine and measured it and he said...it was full and he said wow that he was amazed I haven't leaked any of it out. Anyhow where is the condensor? The fans are side by side. The main 14" one is the one closest to the battery (puller) and the 12" one is closest to the distributor. I was thinking of maybe putting the puller fan on the other side of the radiator but not sure if its gonna fit inbetween the radiator and the other rad. filter (dunno what you call it) so it pushes air in. Any suggestions?

Thanks for your help DAEDALUS

[DAEDALUS]

The condenser is like a radiator for the AC...usually it sits right in front of the coolant radiator, and usually it has its own fan right in front of it. Follow the metal freon lines--they'll lead you right to it. I'm guessing at least one of your fans isn't factory. If I'm reading it right, you have 2 fans side by side, but they're blowing in opposite directions? I think they might do a better job if they're blowing in the same direction, both sucking cool air in from the front of the car.Maybe your tech meaured the weight, or maybe he measured the pressure. The machines do both. Measuring just the pressure is pretty quick....takes only a minute. Measuring the weight takes anywhere from 15-60 minutes to suck out all the freon and then to charge it back. Most places will charge you for a full freon charge if they have to remove and recharge the freon.

[nnkfws333]

Cool I'll try to reverse one of them over the weekend but one question for you. Do you know how you have the radiator and you have a look a like radiator that sits in front to block out debris? Its on a S13. Do you know if it can be taken out?

[ricebike]

"Do you know how you have the radiator and you have a look a like radiator that sits in front to block out debris?"

Uh, that look-a-like radiator that sits in front of the coolant radiator IS the AC condensor.

ok, when I had to replace my coolant radiator, there was a lot of debris trapped in between them, soo check and clean it out as well. Maybe debris is what's keeping the fans from moving air around.

PS: i too still have R12 in my AC & still running strong.

[DAEDALUS]

I doubt you can take out the condenser easily. I've never owned a 240, but on most cars it's a real pain. On my car, I think I would have to remove the bumper. At the very least you would have to evacuate the freon first (legally) and then disconnect the metal lines. Not sure what happens after that. Ricebike's right on about cleaning them out. Since air is flowing from front to back, you might try flushing them out by spraying water from back to front through both. Maybe even drain the radiator and remove it to be able to clean it better. You'll find all kinds of crap in there...twigs, leaves, cigarette butts, cat hair, etc. Be careful not to damage any of the cooling fins.

[nnkfws333]

Sorry for the idiocy but when it comes to AC Im like uh.....Well I appreciate all the help. Im gonna take the main fan and put it in between the condenser and radiator so its a pusher and clean out the fins of the condenser. For the little fan Im gonna place it in the middle. If not lazy probably gonna put a thermostat on there. What do you guys think? Thanks again!

[C-Kwik]

I don't think there is very much room between the condensor and the radiator. Some aftermarket electric fans can be used as a pusher or puller simply by flipping the blades within the fan.

To add on, I think you can only do this if the motor can be spun in the opposite direction by reversing the polarity of the wires.

[nnkfws333]

so how would you swich the polarity? I bought the fan a while ago and wasn't sure if it could be a pusher or puller. Man that really sucks that I Might not have enough room. I guess I can check tomorrow morning to see how much space I might have.

[Nismo1182]

so how would you swich the polarity? I bought the fan a while ago and wasn't sure if it could be a pusher or puller. Man that really sucks that I Might not have enough room. I guess I can check tomorrow morning to see how much space I might have.

make the negative postive and the positive negative of what it is now. DOHC KAs have a puller fan in between the radiator and ac condenser. SOHC KA's have a little puller on the outside of the ac condenser, you can see it from the front of the car.

[nnkfws333]

Has anyone ever tried to replace the condensor/drier by themselves? Im doing it this weekend and was wondering if anyone could give me tips.

[DAEDALUS]

Do you mean the condenser, the reciever/drier, or both? The reciever/drier should be fairly easy. Loosen the clamp, unhook the switches, and slide it out. The battery might be in the way--just remove it. The condenser will probably be a lot harder, but I've never done it.

[RedShred]

I've removed all of my AC from SOHC. The Condensor is a PITA. if you pull off the fan assembly and pull the shroud out, the radiator should come back enough to allow movement of the condesor to move back and out. On the drivers side there is a line to goes in/out of the condesor. That is a mutha of a bolt to say the least.

Good luck. If you fuxor anything up, let me know, I have everything in good shape yet and nothing was tore up removing, except the line that goes acrossed the firewall... that I tweaked a bunch to get out.

[email protected]

[Dattebayo]

hey nismo1182 "DOHC KAs have a puller fan in between the radiator and ac condenser."

Umm i dont know if you just dont own one, but your wrong. Its on the fan shroud for the clutch fan, on the back of the radiator. And besides all that, that little 10" fan wont do diddly squat any way. I have the pusher (12") on the front of the a/c condenser coil and the puller (14") where the stock fan was and it just barely fits top to bottom.

[nnkfws333]

Well I worked on it today. It was a PITA for me. Ive got a 92. Well I changed the drier piece of cake. The condensor was just tideous. I got to remove radiator and battery to pull it out. It sucks.