A/C woes

OK, to make this somewhat not to long winded, I haven't had my AC working for about 5 years, but never really cared when I had a work van. So I've got it all back together now with a replacement compressor and we had it all running at the shop, WITH A TEST PROBE kicking on the compressor. Everything seems normal, but I'm only getting power at the one pin location at the relay when the A/C button is pressed on. The fan turns on, as it should, but I'm not getting power over to kick the relay over to send power to the compressor.

I may not have had the relay figured out but I believe when it is to be used there are 2 12v signals going to it. I'm not getting that 2nd 12V, but the fan does go on so it tells me the climate control is working properly.

 

Any ideas? I'm kinda stumped at this moment

Do you have refrigerant in it?

Yes, it was freshly done with the new compressor, and blowing cold when we had it going.

I'm an AC newbie, but it's something I'd like to learn more about. I'm wondering how much refrigerant is in the system, and what your high and low side pressures were when you were able to get it running at the shop.

Based off that I'd start looking at the pressure switch. I'm not sure if subarus have a high and low side switch but they will have at least one switch that needs to function for the compressor to kick on when you activate the ac. Check all the hard lines of the ac system and you'll find it. It's also a possibility there isnt enough refrigerant in the system to get the pressure high enough to activate the switch, but if you had it blowing cold that probably isn't the case.

FWIW, the AC relay is $6.00 from the dealership. This is the relay in the under hood fuse box.

 

They'll most likely have at least one in stock. I replaced them in both my cars a while back.

I swapped the relay with the one from the fan since they were the same ones. It didn't change and the fan still worked.

 

We did put the specified amount of 134A in the system (a little under 1lb), and it tested out ok.

 

I'll call the dealer and see how much the pressure switch is. It is situated just below the battery, not too hard to get to

Good luck, hope that fix's it. Not having AC this time of year is not fun.

 

How did I get by until the mid 1980's until I have a car with AC.

I can't find the part number for that triple pressure switch anywhere, I'm curious to know what it is when you get it.

Unfortunately, you'll have to drain the system to put the pressure switch in.

May be its time to let a Pro take a look and fix it ...?

Going over my first post... a pro did look at it, tested for leaks and we put on the new compressor, we ran a vacuum on it for 15 mins with no leaks and then refilled the system with the proper amount of 134A. This is when the new compressor was put on because my clutch was seized..

we did watch the pressures on the machine and they balanced out so it seems like the pressure switch was doing it's job.

It looks like it's down to electrical diagnosis with maybe a frayed wire going to the AC relay, I was hoping someone just had this same issue and could help point me in the right direction especially when dealing with the fuse/relay box/ecu if needed

 

 

 

 

I ended up at the dealership this morning to pick up some clips that I ordered. So I did get the part number for the pressure switch, well it's welded to the line. Not cheap... but the part number is.... 73431AG05A