A/C & climate control acting STRANGE

[Huntervf]

I'm guessing these problems are related so here goes:

With the A/C on the air will blow out the defroster vents under acceleration, then blow out the dash vents like normal during deceleration or cruising speed. I just charged the A/C a couple days ago, and now today it doesn't seem to be working at all. Sounds like the compressor isn't even cycling. Furthermore, I've noticed a couple times in the past week or so when it suddenly seemed like the AC wasn't blowing cold. It started out just fine today, but then I had a short WOT run through 1st and after that it stopped blowing cold. It started working a little later then it just stopped blowing cold again, this time while I was just crusing at around 30-35 mph. I injected dye into the A/C system when I charged it last Wednesday...even though it takes a black light to see the dye I've no doubts I'd see puddles of luminescent green if the leak was so bad as to empty the system in just a few days so I believe it's still full of R-134.

I ran an EATC test and it came up 888 (at least I believe that's what it was...rather than just show 888 EVERYTHING on the panel was lit up...is that normal?)

Figures...we finally get some warm weather in Mi and the damn AC decides to get fussy. headbang

<small>[ June 16, 2003, 03:25 PM: Message edited by: Huntervf ]</small>

 

[projectSHO89]

You have two problems:

1) A vacuum leak or distribution problem in the dash. If the vacuum drops, the airflow defaults to the defroster outlets.

2) Likely AC clutch related. There have been seveal threads on this in the last week or two with the needed details.

Steve

 

[MilTownSHO]

Huntervf:


I ran an EATC test and it came up 888 (at least I believe that's what it was...rather than just show 888 EVERYTHING on the panel was lit up...is that normal?)

Yes that's normal it means everything checked out ok

 

[bytor]

I don't have an answer for the other problems, but losing the AC through the vents or entirely is not unusual. There's little vacuum at WOT. And some cars (don't know if this is true of the SHO) will stop the AC and leave it stopped for a long time after any length of time at WOT.

 

[haydenm315]

I think the car will cut off the a/c compressor when under heavy acceleration. The a/c system degrades car performance by a good bit. I think it may be in the 20% ballpark range + - a few %. When you really step on the pedal, the a/c will temporarily shutoff until you begin cruising again. This keeps the a/c system from degrading the performance of the car as much.

 

[91 SHOplus]

According to SHOtimes, the a/c shuts off at WOT as some sorta safety default. The weird venting issues may be your BCM. shrug

 

[DHMag]

91 SHOplus:
According to SHOtimes, the a/c shuts off at WOT as some sorta safety default.

it shuts off because the compressor is not meant to run at 7K RPMs. most Nippondenso compressors dont like speeds over 4500 RPM. ever grenaded an A/C compressor while heavy in the throttle ? i have, scared the bejeebers out of me.

 

[Huntervf]

Well, it looks like the compressor it toast, or maybe it's just the clutch, I dunno. It died on me a couple weeks ago, still had a ton of R-134 in it. Just for grins I threw it on the A/C machine at work, and with a full 2lb charge I had nothing but warm air. The compressor is kicking on just fine, but it's just not pumping. Furthermore, the clutch now is not completely diengaging...I can hear the pulley contacting the clutch plate when the A/C is off. Time for a new compressor I guess shrug

 

[projectSHO89]

If you can see the clutch engaging and disengaging, use an inspection mirror on a long handle to look at the nut on the end of the compressor's shaft. My bet is that it is remaining stationary. That means your clutch is the bad part and the rest of the compressor may be good.

Steve

 

[DHMag]

projectSHO89:
If you can see the clutch engaging and disengaging, use an inspection mirror on a long handle to look at the nut on the end of the compressor's shaft. My bet is that it is remaining stationary. That means your clutch is the bad part and the rest of the compressor may be good.

Steve

if the clutch engages but the compressor crank remains stationary, id pull the clutch and coil off and have a look at the key.

 

[projectSHO89]

Nah, that just means the clutch fell apart. I've seen it several times.

It only LOOKS like the clutch is engaged, but the clutch is toasted.

Steve