Anyone out there have an AC schematic for a '90 - 94 legacy (I assume they're the same). Something showing the mechanical as well as electrical componentry would be nice. Looks like will have to try and troubleshoot intermittent electrical problem on my own. Not knowing anything about AC, should prove a challenge.

what are the symptoms? I had a bad connection in one of the relays on my 93.

Where are the relays located, jimscat? (I could look it up but it's too early out here!)

 

Aloha.

on my 93, drivers side right next to the washer bottle under a dust cover

jimscat:

 

The following is from my original post:

 

My '91 legacy has 175K on it. The AC has never been serviced.

Over the past 3 years of operation the unit has become intermittent. Its as though it has a mind of its own.

Typically, in the morning, when I go to work, the AC is reluctant to come on. Sometimes I'm a mile from the job before it decides its time to cool the car. Other times it may kick on almost immediately and remain that way or go instantly back off. When it does come on, it cools the car as it did when new.

When I go out to lunch and the interior of the car is hot, the AC comes on 100% of the time and operates great all the way to my destination. When I leave my lunch stop to return to work, however, the AC becomes more iffy. It may come on immediately and work fine or have a delayed start and operate intermittently on the way back to work.

Occasionally, I get into the car and drive it for 20miles and the AC works perfectly. Any suggestions?

Since this post I've been fiddling with AC relays under hood. Purchased new after market relay (so big that I had to weasel in with screwdriver) and swapped out with those under hood. Didn't seem to make any difference. Although, AC may now be more intermittent since I've started messing around.

I by no means know anything about the ac. I will take a look in my haynes manual to see if there is a wiring schematic.

 

 

I had to mess around for over an hr before mine decided to work. Now it squeels

The AC system is different. There was the calsonic & zexal ac systems. Then I think in 92 or 93, they went to r134a.

 

If you can provide the year and the system, I should be able to help.

Legacy,

Mine is a 93 and was r12, so it must have been 94 and I know 95 is 134

 

Jim

My car is a non-turbo '91 legacy wagon. Thanks.

This is for a 92, but the diagram should give you some ideas.

 

http://www.main.experiencetherave.com:8080/subaru_manual_scans/1992_FSM_(Engine_%26_Electrical)/

 

Please do NOT try and open the pdf, right click and save as.

BTW, what symptoms are you having with the AC?

The website address you gave is no longer available.

 

The following is from my original post:

 

My '91 legacy has 175K on it. The AC has never been serviced.

Over the past 3 years of operation the unit has become intermittent. Its as though it has a mind of its own.

Typically, in the morning, when I go to work, the AC is reluctant to come on. Sometimes I'm a mile from the job before it decides its time to cool the car. Other times it may kick on almost immediately and remain that way or go instantly back off. When it does come on, it cools the car as it did when new.

When I go out to lunch and the interior of the car is hot, the AC comes on 100% of the time and operates great all the way to my destination. When I leave my lunch stop to return to work, however, the AC becomes more iffy. It may come on immediately and work fine or have a delayed start and operate intermittently on the way back to work.

Occasionally, I get into the car and drive it for 20miles and the AC works perfectly. Any suggestions?

Since this post I've been fiddling with AC relays under hood. Purchased new after market relay (so big that I had to weasel in with screwdriver) and swapped out with those under hood. Didn't seem to make any difference.

Another recent observation: As mentioned above, the AC is reluctant to come on in the morning. Today when driving to work, it seemed the AC would come on when the windows were down. Shortly after rolling them up, it would go back off. Roll them down again, and in a minute or so, the AC would come back on.

The address is good. Your ISP may not allow things to go through on port 8080. Try this:

 

https://www.mail.experiencetherave.com/subaru_manual_scans/1992_FSM_(Engine_%26_Electrical)/

 

From your symptoms, it almost sounds like a pressure switch, or temperature sensor. The temp sensor is in the evaporator box behind the glove box.

 

I believe there is an internal cut switch on the compressors of the 90 & 91 models, but not on the 92-94's. There's also a pressure sensor screwed into the receiver/dryer.

 

Have you checked to see if the compressor clutch is engaged when it's not cooling well? That would be my first suggestion.

I can access this website. Thanks.

The AC compressor clutch is not engaged when cooling is absent. No voltage to the compressor when it is in this state. When clutch engaged, ~ 13V. Definitely some type of intermittent signaling issue to compressor. Will check temp. sensor inside car. Thanks again.