2 A/C Questions - ***UPDATE***

[DJ SHO]

I tried recharging my system last night. No-go. I jumped the switch, and no compressor. But before I did that, I tried to put one can of the recharge kit in. Before I started the procedure the guage read 0, dead ass empty. So in the proper procedure I start installing the first can. It got up to almost 65 psi on the gauge so I stopped it. What's the problem here? Shouldn't I have been able to put the rest of the can in without it getting that high? BTW, it's the crap Walmart setup that had the three cans, the gauge, and all the retro-fitting for converting over from R-12 (which I didn't need of course).

So jumping the switch did nothing. Does that mean the gap is to big or the compressor is shot? Wouldn't it have kicked on regardless of how much freon was in there (when I jumped the switch)? And what's up with the pressure getting that high from 3/4 of the first can being installed?

Thanks in advance.

<small>[ June 02, 2003, 01:27 AM: Message edited by: DJ SHO ]</small>

 

[projectSHO89]

The 65 psi you mesured is the pressure from the can.

This is normal.

You need to focus on the failure of the compressor clutch to engage.

Since the compressor was not engaging, it was not able to create a suction in the low side of the system to draw the rest of the contents of the can into the system.

Nook did a good writeup last summer about his diagnosis of his AC system/clutch problem. SEARCH for it.

Steve

<small>[ May 27, 2003, 07:56 AM: Message edited by: projectSHO89 ]</small>

 

[rangerj]

DJ,

Try applying battery voltage to the A/C clutch. I should become a very strong magnet. If not, the clutch coil is defective. A clutch gap of .035 will work fine, if you want to try that first.

If your system is empty, then you have a leak. Fix the leak. Then properly vacuum the system before adding refrigerant.

Air in the system will give you high pressures, and the moisture in the air will destroy the compressor. You would not put water in your engine would you? rangerj

 

[DJ SHO]

Thanks rangerj for your A/C expertise. I'll give that a try and let u know what happens.

 

[nutorious_sho]

does the clutch come on with the defrost?
thought that was the easiest way to see if there is any problem with it shrug

 

[projectSHO89]

does the clutch come on with the defrost?
thought that was the easiest way to see if there is any problem with it

There's a lot more to it than that.

Steve

 

[nutorious_sho]

It wont diagnose exactly what is wrong, but it will illiminate a bad clutch. I have been told that if the clutch works, than the clutch is good shrug

 

[projectSHO89]

nutorious_sho:
It wont diagnose exactly what is wrong, but it will illiminate a bad clutch. I have been told that if the clutch works, than the clutch is good shrug

Well, duh!

The clutch cannot energize unless the rest of the circuit is also working, regardless of the HVAC mode selected.


Steve

 

[nutorious_sho]

so the HVAC system uses a different system to engage the clutch?

but if the clutch engages, cant you illiminate having to buy a new one? and if the thats true cant you also illiminate having to buy a new compressor?? it still doesnt solve the problem I know but it narrows it down a bit.

just some things i have heard.

I'm in the prosses of diagnosing my own ac right now. I had it refilled last November and it worked fine, it blows nice warm air now and my clutch isnt engaging. my next step is to jumper, im crossing my fingers that it is just the coil or the low switch and not an electrical problem...

Jason

 

[DJ SHO]

Well I tired applying power to the switch and I can't tell if the coil acted as a magnet or not. It seems like I was just shorting the positve and negative leads that I was connecting to the battery. Is it supposed to be like that? Seemed as if there was an awful lot of current flowing thru when I did that (not sure of how low the resistance of the coil is). Anyways, can someone tell me a little more about how the system works and/or is setup electrically (meaning the cycling switch, compressor, things like that)? If the cycling switch is bad, I won't be able to turn the compressor on, correct? I've only had this car since Oct and I have no history on its A/C problems. This car had only 8000 more miles than my white 95 ATX that I sold in Dec, and I never ever had any A/C problems with that car. Blew ice cold when I sold the car. This current MTX is starting to be a p.i.t.a.

 

[rangerj]

DJSHO,

Read this carefully, please.

The low pressure switch prevents the A/c clutch from engaging if the system pressure is too low, that is not enough of a charge (usually).

The two wires at the switch connection are the same wire with the switch in between them. The switch "connects" them. So, to "jump" the connection put one end of a wire on one side in the connector, and the other end of the same wire on the other side of the connector.

You will have bypassed the low pressure switch. Now with the KOER and the A/C turned on the clutch should engage. If it does, either the switch is bad, or the system is low on refrigerant. (guages will answer that question.

If it does not engage, check the wires for continuity. You can also check at the A/C coil connection for Battery voltage.

Next, if the A/C coil is not activated by the above proceedure, then you can unplug the A/C coil and apply battery voltage to the A/C coil directly. It should become a powerful magnet. If it does not, it (coil) is defective.

I hope this clears up the test proceedures for you. rangerj

 

[Nook]

Not sure if this will help, my own experience trackign down A/C problems

http://www.utahfordclub.com/ace.htm

 

[projectSHO89]

Nook, Yeah, that's the one I was referring to earlier. Wish someone would pin that one to the top for the summer.

so the HVAC system uses a different system to engage the clutch?

but if the clutch engages, cant you illiminate having to buy a new one? and if the thats true cant you also illiminate having to buy a new compressor??

Same circuit for the clutch. No difference. Of course if the clutch engages, you probably won't need a new one as long as the rest of the clutch is okay. Engagement of the electro-magnet is only half of the clutch. The clutch friction material is the other.

In order for the clutch to be energized during any HVAC mode that calls for it, the low-pressure switch has to be closed (adequate charge), the relay module has to be working (clutch coil relay is in there), and the PCM must not have commanded the relay module to cut off the A/C clutch (WOT Cutout).

rangerj, a point: With the low pressure switch bypassed, the clutch will be capable of energizing regardless of the state of refigerant charge providing the rest of the circuit is working.

All: Be aware that newer models have more complex control systems for the A/C clutch. You have to consult the EVTM or equal for your specific model year.

Steve

<small>[ May 31, 2003, 08:13 AM: Message edited by: projectSHO89 ]</small>

 

[nutorious_sho]

First off I would (along with many others i'm sure) like to thank anyone and everyone who is knowledgeable about these problems and others for helping those of us who dont know sh*t, or do and just got some bad information somewhere else

I will be jumpering the switch today and i am crossing my fingers.
I took a look at nooks page on ac problems a few days ago, I was very impressed.

 

[rangerj]

PROJECTSHO89,

Steve,

I'm glad you made the point about the jumper enabling the clutch to be energized even if the system does not have a proper charge.

The object of the jumper is to TEST the system, and is NOT intended to bypass a safety feature.

Once the test is completed the jumper wire should be removed. The idea is to find the problem and fix it, not to bypass it and "keep on trucken".

Neither the low pressure switch, high pressure switch, nor high pressure relief valves should be left disconnected, made inoperative, or bypassed. They are there for a reason.

Thanks Steve, good catch! rangerj

 

[rangerj]

Nook,

The Utah Ford Club A/C test proceedures, with pictures, is outstanding. Are you the author of that article?

Steve is right, that post should be pinned so it is accessable all summer. Hey Bizzy, can you arrange that? thumb rangerj

 

[Nook]

Yup, I did that myself, got my digital camera all greasy in the process, but oh well. I added a little trick that the A/C shop told me about when we recharged a SLO this weekend.

N

<small>[ June 01, 2003, 06:47 PM: Message edited by: Nook ]</small>

 

[DJ SHO]

UPDATE:

I had added that one can of freon last week and had nothing.

Yesterday I notice that the compressor does work. It cycles on and off when using the defrost and MAX A/C and the other two functions like it normally should. Maybe applying voltage to the switch gave it a jump start last week or something.

So the question now is, is it worth it to just fill her up with the freon and see what happens (only a few bucks worth of freon aint gonna break the bank)? The compressor is working, but I just didn't fill the system with enough to provide cold air. It's obviously enough to get the compressor moving though. Hey if it doesn't last all year I can always repair the leaks next winter, right? ****, I think I'm just gonna go do it. I want cold air for the summer...it's not far away.

<small>[ June 02, 2003, 01:05 AM: Message edited by: DJ SHO ]</small>

 

[Nook]

If it's just cycling on and off liek that, odds are you likely just dont have enough coolant in there.

So, where did it go ?

1) Find the leak. You can check the connections on all the lines and look for the leaky ones. You can tell it's leaking because there will be a big collection of mung where the oil leaked out and started gathering dirt.

2) Get one of those A/C UV dye kits, its like a recharge can, that you put in for the freon, then look for leaks with a blacklight.

3) Add one can of freon to make the unit work for now, then find the leak. Get one of those AC coolant leak detectors, it's a palm pilot sized unit with a cord and a wand, you put the wand near all the connections and it beeps or buzzes when it detects a leak. I have one and it's worth every penny, usually about $199 at better parts stores.

If you find the leak, start replacing orings, now's a good time to get one of those a/c uncouplers kits at a parts store, should be under $20.

4) If you cannot find the leak, take it to a good A/C shop and tell em you want to find the leak, and evacuate it at the same time. They will pull a vacuum on it and hold it for like 30 minutes to see if the vacuum holds. If it does, go for a recharge/conversion. If it DOESN'T hold, head on over to teh Ford dealership, and get a nice pile of O-rings and start replacing, shouldnt cost $20 in O-rings. Once all the orings are repalced, take it back for another vacuum check and recharge if it holds vacuum.


N

<small>[ June 02, 2003, 07:35 AM: Message edited by: Nook ]</small>

 

[rangerj]

Nook,

And anyone else that knows the answer to the following question.

Is the SHO A/C compressor, that is the Nipon Denso 10P15F one of the Ford compressors that is "Teflon" coated on the inside? rangerj