freq

iTrader: (6)

I just got my system changed over to r134 and recharged, but the mechanic said that the ac compressor isn't getting power.
As far as I can tell, there's only 1 wire going to it. A black wire that connects on the top of the compressor.
Is there something I'm missing?

classicauto

iTrader: (3)

fuse?

J-Rat

iTrader: (2)

Just to get power to that one silly wire, you have to go through some interlocks. Most noticeably is the Hi-lo switch. If for some reason there is not enough refrigerant, or there is too much, that compressor will NOT switch on.

What am I saying? If the fuse is good, check your pressure.

DragonRx7

You're in Jersey. You don't need no A/C. Suck it up, wuss.

HAILERS

He's saying to go to the low pressure switch located on the drier in front of the radiator. Pull the two elect leads off the pressure switch and jumper them together. Now turn the key to ON and the A/C to on and see if the clutch on the compressor pulled in or not. If it pulled in the system is low on refrigerent.

Secondmessiah

i dont have the answer, but i do have a good question: why the **** cant your mechanic figure this out? isnt that his job? wasnt he trained in this? i dont know if you should continue going to this mechanic

Silver Devil

J-Rat and HAILERS make a good point. That is what I would check first because it is easy and you dont need to deal with some mechanic and it will most likely solve your problem. I pasted what GregW had posted on teamFC3, which is the same as what J-Rat and HAILERS
are saying but with just a little bit more detail. Good luck.

ok, pull the plug off the pressure sensor. It is on the line comming out of the reciever dryer. It is the only electric sensor on the lines. It is up above your oil cooler by your pass headlight. pull up the black cover. You should see it.
Well turn on the ac in the car and then pull that plug and insert a jumper wire. If the ac in the car is on when you short out this con the compressor should start to spin. Hence the name pressure sensor.

Whitewidebodyrx7

yea forreal you drive an rx7 as well you should be more interested in takin the a/c out

freq

iTrader: (6)

I bypassed the logicon and rigged an inline fuse and a switch into a wire that I wired between the battery and the compressor. Turned the car on, put the fan on Max, flipped the switch. I get nice, cold ac.
It's either the logicon or the ac fuse.
Which is the AC fuse? Mine aren't labled.

J-Rat

iTrader: (2)

Did you get a pressure reading yet?

Jcadette

I suffered through this issue
THe system was vacumed and fully charged
The compressor interlock worked when power was applied
THe trbl was the ecu. there is a the signal to switch power that was not being sent by my computer. replaced it and it works like a champ
Find a good wire diagram anda you can trace it out

Good luck it

HAILERS

You didn't even check the relay or pressure switch out and you now think it's a fuse or the logicon. Give me a break.

classicauto

iTrader: (3)

^^

You should be aware that if you run that system bypassing that pressure switch, you could potentially blow that system apart?right?

Mazda may have put a FEW unecessary things on the car, but I assure you a high/low pressure cut off switch is not something to mess with on a car with functioning A/C.

Juan

iTrader: (28)

When you say "replaced it and it works like a champ" what did you replace?

The a/c in my syster's car was recharged and the shop couldnt get the compressor to activate using the logicon's AC button. The button wouldnt activate the compressor and the buttons light wouldnt turn on. All the fuses were good. The guy checked the relay as stated above and the compressor turned on.

I know FCs are notorious for bad logicons so I replaced it with a used one I had and it still didnt work.

MARTIN

He's not saying to keep it like that permanently. He's trying to diagnose the problem. By jumpering the hi/lo switch, you can either count that out or rule it as part of the problem...

Rice_cooker

I say someone posts a DIY'ers write up on how to troubleshoot and diagnose a non working A/c.....
Can we get a professional in here?!?!?

tinmann55

iTrader: (1)

I am going through the same thing with my 91na ,I changed out the logicon twice . the hi/low pressure switch twice and still no power at the to the compressor. compressor would run fine with twelve volts directly from the battery. So i changed out the ecu and now have power at the compressor. So it was the ecu not throwing a signal to switch power. But that ecu had other issues with accleration.
My question is can anyone id the ac pin in the ecu so i can try a resolder it on my good ecu. If not Icemark if you are out there ,is this something you can fix?

classicauto

iTrader: (3)

Yeah sure!!

THATS A GREAT IDEA!

oh wait.....what's that button up top? s-e-a-r-c-h?.......straight from the archives, lots of great info.

https://www.rx7club.com/2nd-gen-archive-72/official-its-summer-there-going-million-ac-questions-thread-308839/

Rice_cooker

LOL
Good job........I hate how general the search results are.....maybe I just don't know how to utilize them well but i almost never find what I am looking for.