Since I put the new parts in the ac system, I now hear the freon flowing through the rear evaporator at ALL times when the compressor is on. Air is never really cool from the rear. ac is mediocre in the front. If I bring the rpms up to about 1500 the front ac gets 5-8 degrees cooler.

Something wrong with the rear ac system maybe? I always find myself looking back to see if I left the fan on because its that loud in the evaporator. Pressures still arent right in the ac system. Then, Yesterday my e Taurus fan melted the 40 amp maxi fuse and almost melted the connecter together because the ground wire is a 12 gauge and the positive wire for high speed is 10 gauge... don't know what ford was thinking there, but its a moot point now because I put my old clutch fan back in. ac is now even worse at idle. cooling about 15 degrees below outside temps. pressures still not right

 

Are you sure it's not condensed water in the rear unit from a clogged drain tube?

 

I don't think so. The drain tube has always worked. Also, after so long it would start coming through the headliner and it hasnt done that. It's pretty weird

 

I get a kind of woosh sound from the rear until when I first turn the ac on usually.

 

Okay. See I've experienced that before. Where itll make that noise right when the ac comes on. But this one starts when I turn it on and stays until i turn the ac off. Just odd. I don't know what to suspect now

 

Well there are 4 things in the ac system controlling the pressure in various sections of the a/c (barring any possible restrictions somewhere). So one of those is going to be why your pressures are off and most likely why you're hearing what sounds like inconsistent refrigerant flow (or whatever that noise is) through the system.

- amount of refrigerant in the system
- compressor
- front expansion valve
- rear expansion valve


As for performance of the a/c, that's down to the pressure differential between the high and low side, how much heat can be removed from the system via the condenser, and the ambient temp/humidity going through the evaporators.

Now I will say that my a/c isn't exactly performing excellently when it's 95-110 degrees here, but my rear a/c usually feels noticeably warmer than the front, and that's with it having a brand new expansion valve too.

 

Okay. So it's pretty possible would you say for the rear expansion valve to be bad? It's brand new, but I know that doesn't mean that its a good part. If I made some block off brackets or bracket out of aluminum and just blocked the rear ac I wonder if I could get my front ac working better. Now that I'm back to my fan clutch i get about 15 deg cooler than outside temps at idle. About 25 cooler when it's at 150" rpms and goin down the highway

 

No I don't think blocking off the back is a good idea. You'd end up loosing refrigerant capacity. I didn't originally have the rear ac, and the extra capacity of the system with the rear unit did seem to make the ac perform slightly better.

 

Okay. What would you say about the compressor? As in chances it's old and tired. It was used when I put it on a couple years ago. But also it could be the rear expansion valve I guess due to the noise I'm getting

 

I don't really know enough to say about the compressor. I mean I can certainly see it being possible for it to lose compression over time like an engine, but I hate to make a guess like that and have you spend money you don't need to. If it helps though I ended up replacing my compressor last summer because I broke a bearing while replacing a leaky seal in my original one and I didn't see any difference in performance... other than the new one not leaking.