Looks like I missed you by a day, but there is a product called "Freeze-12" that is for charging older R-12 systems without any change to oil/O-rings, etc. It is readily availbale vie eBay and other online retailers. I have used it personally in my 78 vette and it works great.

Oh well, maybe next time. Ironically I learned of it's existence right after I had my runners system converted to R134.

Once you get this all worked out I would love to see you post up a diagram if possible, as I know that I'll be doing this next month and I'm sure I'm not alone.

Good Luck

 

Ya ditto that. Anything that you guys can post on the AC would be great. I know absolutely nothing about AC. DOnt even really understand the components and what they do.

I think I could closer to building a nuclear bomb from household chemicals and bailing wire than getting this AC working.

Got to finish swapping back to 5 speed before that. I'll deal with when the "new" ECM comes in from the East Coast.

 

I think I am in the same boat as you UKrunner. My system ended up being basically empty. I did have something in there, but nothing much. I also got the wrong kit. I got a recharge kit only. Napa was closed, so I could get their recharge and retrofit kit. And Knecht's was out of theirs. Today I will be going to Napa on my lunch to get the right kit. Didn't know the connections were even different. Hopefully after the system is filled up, the pressure switch will work.. Did the kit come with the oil that is needed? I am seeing where ppl say you have to get the old oil out first? How would you get the old oil out? If the system is empty is there anything else I need to do??

 

Technically you are supposed to remove all old oil and refrigerant and vacuum any air out of the system. Air interacts with r134a and creates sulfur hydroxide.

Me? I did non of that. I used the conversion kits oil and a cam of r134a. I plan on changing all o rings out over the winter but I need A/C right now for my 2.5 year old.


Ok, so I've been doing a little work on the wiring today. First thing to overcome was the completely wrong wire colors in the wiring diagram. Every wire was wrong. Nice.

Second thing was making sure the double pressure switches were closed and providing 12v to pin 3. They are, so this means my A/C has enough charge in it and will function when the wiring is fixed. The thermistor is working as there is 1.08V on that pin. There is 12V on every pin that there should be and the light in the switch is on.

Changing the adjustable resistor for idle speed turn off, on top of the A/C amp does nothing.

ACT pin from ecu to A/C amp is at 0.8V.

This is as far as I've got right now. Will update as I can.

(I'm home alone today with my son who is napping. When he wakes I'll have to stop.)

 

WORKING!

Connect 3.0 amp up as per 3.0 diagram. Connect the 3.4 ecu pins except act pin.

The act signal from the 3.4 ecu is a momentary signal. The A/C will not run if this wire is permanently connected. If you touch it while running it will shut off the A/C but as soon as you remove the connection the A/C will start again. I see this as the ecu being able to control if the A/C is on or not - completely over riding the control the A/C amp has.
The act pin on the ecu has to go to 12v for the A/C to work. The ecu pulls this pin to ground internally. Consider this pin as a remote control turning the A/C amp on or off as the ecu sees fit.

I will work on this to see if it's possible to use this pin to allow ecu control.


Also wire in and use an idle up valve as the rpm's drop considerably without having this vacuum valve connected.

 

The proper procedure for charging the system is to pull a vacuum on the system using a vacuum pump. I got mine at Harbor Freight. It's cheap and works off of my existing air compressor.
http://www.harborfreight.com/air-vac...ors-96677.html

Once you achieve the proper vacuum (as per FSM) you can then begin to charge the system using manifold gauges. (also available cheap at HF) You can also just use the budget hose that comes with the cans usually, but the manifold gauges allow you to charge the system according to the proper high side and low side pressures safely.

If you are converting to R134 from R12 you are supposed to flush the system of old oil, change the o-rings to the style that will hold up under the new R-134 refrigerant then recharge system with first new oil then refrigerant. This will ensure longevity to the system.

I have known plenty of people that say screw it and just put R134 in without properly converting it over. Their systems seldomly last more than a season without seizing the compressor or developing leaks that require constant recharging.

Another note: It is always a good idea to replace the dryer after you have opened the system. It is a relatively inexpensive part and keeps the moisture down which is an A/C systems' nemesis.

 

well I went to fill the system, and I got about half a can through and I started hearing a hissing sound coming from the high pressure line right where the battery was. So needless to say I have a leak. Hopefully I can find that hard line at the junkyard or something. GRRRR why can't anything every go right. But hey at least before that happened, I went and checked my air and it was colder than the ambient air was! so it was starting to work. And the dryer started to have bubbles in it. So UKrunner, you are saying to not connect the original wire from the 3.0 amp that went to ACV to the ACT pin of the new ecu? for now you just have that pin empty? or did you do something else with that wire...

Thanks,
Chris

 

The ACT wire is disconnected. The wire is still there, just not connected to anything.

 

on my runner there is this switch or sensor in the line.


After reading through the FSM's I think that this is a hi/lo switch.

AM i going to have to have someone graft this onto my 3.0 lines?

 

Thats on your donor vehicle?

If you are using your 3.0 amp, you shouldnt need that as your vehicle will have the dual high/low pressure switches all ready and they will be wired to your A/C amp. Really, during this swap the only 2 wires that should be different are the ones to the ecu, and only one of those needs to be connected. Mine works fine, the ecu even controls the idle speed up. I removed the A/C idle up vsv that the 3.0 amp controls. It even cycles and the vent temprature on recirc goes from 43 - 46 deg F and pulling in 90 deg air from outside maintains 53 deg. It works perfectly.

 

LOL really so much difference from all over these threads, and it really comes down to one wire that needs to be sent to the ecu, and the clutch being changed out to the newer one. I knew it had to be easier than what I was reading. I can confirm that you are correct UK, as mine started working before the leak became apparent and I could hear it over the sound of my engine.

 

Don't even need to change the clutch over. I used the 3.4 compressor housing because I couldn't get the bolts undone on my 3.0. I changed the plate over where the hoses connect.

 

oh. I just switched clutches as I THOUGHT the system was still pressurized and working. I think if I get really motivated I will pull everything apart again and swap out the compressor I got with the clutch. so I have the newer compressor that is for the r134a crap.

 

okay guys, been running with A\C for what a week now? I am noticing that when I first start the motor now, my idle is higher than it use to be. And it doesn't go down to the normal 750-900 rpm range. This is of course with the a/c off. The idle slowly goes down, after driving and allowing the engine to warm up, but usually just above a grand now. This only happened since doing the A/C. Don't feel like messing with it to much, as its all working, but thought I would share this and see if others have noticed this. Also
after the motor is fully warmed up, and I go to start it, the idle jumps up to around 2k, then it will start to go down within 30-45 secs. But again only going to just over 1k rpms.

-Chris

 

Did you connect the vacuum idle speed control valve? Also, check disturbed vac lines for a leak.
The 3.4 ecu controls A/C idle up so you can remove the 3.0 A/C idle up valve, associated vac lines and electrical.

 

UK..where is the stock 3.0 idle up? Did it go with the motor, or is it in the cab? I would assume somewhere under the hood.

Gotta start on this after the ref passes this thing..........knock on wood.

 

Its under the hood, mounted with 2 other vac valves that are NOT for the 4wd ADD. I'll see if I have a picture. Its easy to identify because it has a vac diaphragm and a big screw and spring assembly. That assembly is adjustable and what it does is adjust the idle speed when the idle up valve is activated.

 

Hey do you still have the climate control for your '97? My fan switch just took a dump this evening. Would prefer just the switch if possible.

 

I believe I do. I'll look through my boxes and see. I'll get back to you.

 

ya I did check the the vacuum lines. They are all fine, and I do have the vacuum idle control valve hooked up. It was acting almost like that wasn't working. But it does work...