'89 AC help...???

[Magmotor]

Just had the AC checked out and had one lb added. It wasn't getting as cold as I thought it should. AC runs cold now at cruising but when I come to a stop, it blows hot air. It idles at 6 and when I take it up to 8 or 9 rpm she start blowing cold again. Any ideas?? Hope it ain't the compressor..!! That's all I need. Thanks for any info...

 

[tkrphxr]

I hope you don't think this is dumb but have you checked to see if the cooling fans are running? It may be you're possibly not getting any airflow over the condensor when stopped. Might be worth a check. course the water temp should be going up also when you are stopped. Good luck Charlie

 

[2tone81]

Sounds like dead condenser fan and or temp sensor...Jim

 

[Magmotor]

Thanks for all the good info..! Had the freeon added last week. We stood there and waited for the main fan to catch, came on at 225 but didn't wait too see if the AC fan ever blew...The higest temp I can get this car up to is 230, period...It won't go over that , no matter what I do, AC on & everything...One time when the bridge was up, a 20 min wait, I pulled up 6" from one guys exhaust just to see if I could get the temp up, but nada....I could hear the main fan come on and it goes right back down to 220-223...I'm having a mechanic over tomorrow to check the timing and fuel usage, 18mpg, smell gas when I shut it off. I'll definetly check the condenser fan and switch...thanks again..!!

 

[69MyWay]

I have had this problem before, and seen it on several , Your problem is the a/c is not triggering the fans. The engine temp is, but a/c isn't. So, as long as you are moving, air is flowing, it will blow cold. When you come to a light, the temps go off the chart on the condensor.

You may end up having to hard wire the trigger to the fan relay off the fan clutch wire. For some reason, when the computer no longer wants to play nice and make all this happen, you are stuck.

I don't trust the electronic system, so I like to add a small relay that uses the 12 volt plus signal from the a/c clutch to close the relay and send a ground signal out to the factory cooling fan relay and force it to engage the fans. It will virtually guarantee you always have the fan kicking as long as the a/c is attempting to pump. Plus, when the engine simply hits full temp, the fans will still come on as normal regardless of this mod.

 

[Magmotor]

Thanks for this great info BUT...( I bet you knew this was comming) I ordered a Service Manual from Helms 1 1/12 months ago. I opened the package a month later and was looking at a service manual for a '69 Sabura or some alien vehicle from another planet..they told me it would take another month or so to get the right one so I told them to keep it...anyone out there have a spare '89 sitten in the closet I'd be gald to buy it.

Question:
1) Did you wire both fans to come on?
2) The two black wires going into the clutch, did you cut one and splice?
3) The relay attached to the main fan shroud is the main cooling fan relay?
4) If I'm sitting and the cabin temp reaches the cuttoff temp and shuts the AC down, I'm right back where I started???

THanks again for this great insight to this..!! It definetly looks like a wiring job is the answer to this problem...I just gotta figure out how to do it now...:confused

 

[69MyWay]

How good are you with wires?

Here is an answer, but not the "textbook" technical answer

Go to the store and buy a standard fan relay for your car. Study the mini shematic on the top. It will show you which poles are used to pull the relay closed, and which two connect when it is closed.

Now, go to your cooling fan relays that are on the left front frame rail next to the radiator. With a test light you will find which wire is the "key on power", the two heavy wires that makes up the actual fan power wire, then a (I think it is green with a stripe) "ground feed wire" that comes from the computer.

Mount your new relay next to the two others. Run a fresh wire to chassis ground on one side of the coil pole. Splice into the harness on the a/c clutch on the engine. Run that wire all the away around to the new relay. Feed that into the 12 volt power side of the coil in the relay. Now, run another wire to chassis ground and into the relayed side of the new relay. Run a fresh wire out of there and splice it into both or just one (I prefer both) of the other relays little green wire. This is the one that sends a ground signal into the relay to close the coil to bring the fans online.

There you go.

Now, when the clutch is engaged, the cooling fans will trigger.

 

[Magmotor]

OK Thanks much...!!

I'll wire it up and let ya know ..

 

[2tone81]

Go on a search for Service advisory Issues for your 89....if its anything like the 88 I'm considering to buy , 89s had some gas issues........as in history of vehicle fires. Jim

 

[Magmotor]

:eek well that certaintly didn't make my day hearing that but....If it's an issue I'd like to know more about it. I checked the bulletins on this site for the '88-'89 and found none on fire hazard. Could you give me a little more insight on this like, where to find these bulletins so I could head off perhaps a major disaster???

 

[2tone81]

www.c4vettes.com

Check out the c4 website .......defects and service advisories......some stuff you've been through.....some stuff you don't want to happen............interesting history for a 30,000 dollar vehicle. Jim

 

[Magmotor]

I did check those out and plenty more sites for that issue, gov sites for recalls, called every GM dealer on the coast and e-mailed GM themselves. No one has ever heard of a "Fire Hazard" or a "Service Bullintin Issued For A Fire Hazard" with any '89 corvette or for that matter any corvette at all. You want to copy & paste this Bullintin you've got and send it too me in a private e-mail. I'd like to see it.
Every car has their goods & bads. I don't care what you buy or how much you spend. It's the nature of the beast.

 

[2tone81]

Your right, technically. 89s had no listings for gas leaks ,fumes or fire........but look at the 88s....(same basic car) under defects section. (I knew I wasn't just seeing things)-and this is when the cars were new

ODI ID-310890-fumes
" "-312281-" "
" "-312650- fire
" "-319085-fumes/leak
" "-340586-fumes
Your 89- fumes- Do we see a pattern here? Jim

 

[Magmotor]

Thought I'd let you know the outcome of the wiring job...welp...never got that far..The car went down hill quickly...back fire when letting off at high rpm....lousy fuel milage....8-11 mpg.....and the stainless steel exhaust tips turned solid black inside.....put a Tech 1 on the computer and it wouldn't read the data...bottom line....new ECM.... that of course we all know controls just about everything...including the high pressure switch that turns the cooling fan on when the A/C is running & the clutch not engaged.....I even have my "instant mpg" and "average" back.....Everything is sunny side up now....Thanks for all the good advice and info:

 

[69MyWay]

Where did you buy the new computer....mail order, local store, used????

 

[Magmotor]

At the Chevy dealer here in town...

 

[2tone81]

Glad to see its on the road again! Jim

 

[Magmotor]

Thxs...!!! me too....:dance everything is working beautifully now....back up to 19-21 mpg...depending on the mood i'm in...:s