AC diagnosis

[fast4door]

Did a little work to try and figure out why the ac isn't working on my 92. After doing some checking I found out I don't have power to the connector at the compressor. Have power at the low pressure switch but nothing at the other connector. Had the car running with the ac and the connector unplug to check for power. All fuses are ok so is there another switch or relay under the hood for the ac? Any tips on what to do next?

Joe

 

[projectSHO89]

Joe,

Visit the Electronics section and see the stickied post regarding the IRCM/CCRM.

In amongst the BS posts, there is a description of HOW the relay module works. I also appended the schematic for the IRCM module in your car.

Once you have those in hand, see if you can determine if the clutch relay in the box is working or not. Any questions, ask them here.

Steve

 

[fast4door]

Thanks for posting the schematic steve now how do I check the relay for the ac clutch?

Joe

 

[projectSHO89]

Thanks for posting the schematic steve now how do I check the relay for the ac clutch?

Joe

Verify that you have the correct inputs per the write-up. If the inputs are correct but the output is not, the module has failed.

Steve

 

[fast4door]

Ok did a little checkin and it seems the E fan isnt working either. Car never runs very warm, checked the connector going into the fan coming from the IRCM and have no juice going to it. At this point I am thinking the module is the problem.

Joe

 

[turbo79]

Ok did a little checkin and it seems the E fan isnt working either. Car never runs very warm, checked the connector going into the fan coming from the IRCM and have no juice going to it. At this point I am thinking the module is the problem.

Joe

Seems to me that you wouldn't have juice coming from the IRCM to the fan unless the ECM was sending a "it's time to turn the fan on" condition - that is, a reading from the ETC sender saying that the engine had reached the temparature where the fan is needed.

Panel of experts (there are a lot of you here), correct me if I'm wrong..

 

[SHOZ123]

The PCM will command the fan on when the AC is on and under certain vehicle speeds.

 

[fast4door]

Car sat in the drive way at idle for well over 45 minutes and fan never kicked on. Car actually started to get warm. Never been a problem. checked the wires in the pin locations for the ac and not getting power out of them at all so gonna try a new IRCM and see what that does.

Joe

 

[fast4door]

still havnt found an ircm. Messed wiith it today. put power directly to the compressor with the car running and still nothing so does that mean the compressor is toast?

Joe

 

[SHOZ123]

You mean CCRM. This is the moniker needed for post '96 vehicles. The SHO CCRM is common to all Tauriises of the same year and IIRC for the entire G3 run. If not for the '96-'98.

 

[fast4door]

yes ccrm sorry.

 

[projectSHO89]

You mean CCRM. This is the moniker needed for post '96 vehicles. The SHO CCRM is common to all Tauriises of the same year and IIRC for the entire G3 run. If not for the '96-'98.

Paul: PLEASE go read the stickied post referenced above! Your information is NOT correct for 1st and 2nd Gen SHOs.


Joe: Again, see my last instruction. If ALL the inputs are good (see stickied post) but the output is not, the module has failed.

Steve

 

[fast4door]

I did and there was no power coming from the wires for the ac on the module or the e fan. But shouldnt I have gotten something from the compressor when I Put power directly to it?

Joe

 

[itwonder]

Have power at the low pressure switch but nothing at the other connector. Had the car running with the ac and the connector unplug to check for power.

I have not seen where you have done the basic check for a low pressure or low pressure switch problem. It's good you have power at the LPS connector. Next test: jumper that connector and turn to A/C on.

...shouldnt I have gotten something from the compressor when I Put power directly to it? Joe

Yes, the clutch should engage if you connected your clip leads correctly. One of the pins on the clutch must be connected to ground. The other must be connected to +12V , preferably through a fuse. You can do this test without the car running. You will here a click when it engages.

 

[SHOZ123]

Paul: PLEASE go read the stickied post referenced above! Your information is NOT correct for 1st and 2nd Gen SHOs.

Steve

Sorry wrong forum....... But the info I posted was correct. :angelnot:

 

[fast4door]

I have not seen where you have done the basic check for a low pressure or low pressure switch problem. It's good you have power at the LPS connector. Next test: jumper that connector and turn to A/C on.



Yes, the clutch should engage if you connected your clip leads correctly. One of the pins on the clutch must be connected to ground. The other must be connected to +12V , preferably through a fuse. You can do this test without the car running. You will here a click when it engages.

have power a the low pressure switch, forgot to mention I had already tried jumping it, guess I could always try again. Tried checking the compressor with the car off and got no clicking at all. When i checked the wires for the ac compressor from the relay box I had no power from them at all, figured this out by checking to see if I had power at the connector that runs into the compressor. Need to try and get this resolved this week cause i need to use the car for a road trip this next weekend.

Joe

 

[projectSHO89]

Joe,

This isn't rocket science. Don't make it harder than it needs to be.

I'd suggest proceeding as follows:

First, test the clutch coil circuit electrical continuity.

Disconnect battery and the connector to the IRCM. Use your ohmmeter to check resistance between pins 16 & 23 of the IRCM wiring HARNESS. You should measure between 3 and 4 ohms. If you do, the clutch coil and the harness are showing as good and you should then measure the clutch gap below.

If you measured an open circuit (infinite resistance), crawl under there, disconnect the plug on the coil, and measure the resistance at the coil. If it still measures open circuit, the coil has failed and needs replacing. If you now show correct resistance, one of the two lines from the IRCM connector to the coil connector is open.

Check the clutch gap:

Use a feeler gauge and measure the air gap between the clutch face and hub. It should generally be between 15 and 30 thousandths. If excessive, the clutch won't energize even if properly powered. Tapping it with a wooden handle, however, will often make it engage if the clutch coil is otherwise properly powered. If excessive, perform a shimectomy.

Do all this and report your results. Do NOT skip around or gloss over or omit relevant details.

Steve

 

[fast4door]

Ok messed with the car some more today. Followed the steps you posted and all checked out fine. For the heck of it i rechecked the low pressure switch. turned the ac to max and had a fresh can of fridge hooked up in case the compressor kicked on.As soon as I jumped the switch the e fan kicked on but the compressor did nothing so I lightly taped on the clutch with a screw driver and magic compressor kicked on. So its the low pressure switch now as for having to tap on the clutch to get it to release whats causing that? Shim need to be taken out? I havn't checked the clutch gap yet so i guess thats the next step.

Joe

 

[hawkeye18]

Do a KOER test; if the fans turn on then, the IRCM is good. If they don't turn on, the IRCM is bad.

If the fan came on when you turned it to MAX AC (which is what you should turn it to in order to fill or test it), then obviously the IRCM is working. I was actually going to recommend the broom handle method next, but obviously you beat me to it! Yes, you need to re-shim your compressor. It's not as hard as you'd think; the instructions are on the forum. You'll want to remove the battery and tray, and alternator to get easier access to the compressor face. Some people have unbolted the compressor and tilted it up for easier access; I've found this isn't necessary, but I guess it can't hurt.

Invest in a very good set of snap ring pliers. If you believe even slightly that time = money, the extra cost (~$50-60) for a good set of pliers will prove well worth the investment. If you don't believe me, go out and buy a $10 set of SR pliers. After four hours of cursing and swearing and bleeding, you'll go out and buy the expensive set anyway.

 

[fast4door]

thanks gonna tackle it this weekend. Just glad that the compressor works lol. So since I had to jump the low pressure swithc does this mean it needs to be repalced? Wirth the freon i put in the car I was amzed how cold it was blowing it was cooler than my 93 cobra lol

Joe