My 4Runner had factory AC... I just need to figure out how to hook it up to the 3.4.

Here is what I think I want to do:

Run the 3.4 compressor with the 3.0 top plate so lines from the '90 will work. I'd like to run R134 throughout the system, thus wanting to run the more modern compressor.

I assume I will also need to change out the rest of the O-rings to something that will work with R134?

I assume I'll need a new dryer... but what else? The system has been "open" as I had a line break some time ago before the swap. I have had all the opening capped, and plan to get a new '90 line to get everything connected again.

I am not sure about the wiring. I have the factory switch, and the wire marked on the 3.4 harness... but are they compatible? My concern is there might be some change like with the oil pressure sender or tach between the 3.0 and the 3.4.

Any ideas or additional comments would be greatly appreciated.

 

The shop that did my AC service converted the fittings over to R134 fittings, I can't remember if they changed any O-rings then, but it had a leak afterwards and I think they did change at least one O-ring at that time. They also added oil to the compressor...my memory is fading...here's the post I did at the time:
https://www.yotatech.com/1015770-post315.html

The AC topic started on page 10 on my swap thread:
https://www.yotatech.com/forums/f160...5/index10.html

But ORS did the wiring for it as part of their wiring harness so I can't help there.

Oh yeah I replaced the receiver/dryer too, and before I took the old compressor out I had a friend at the dealer vacumm/discharge all the old R-12 out. It's best to replace the dryer right before you recharge and pull a vac on the system before recharging.

Its been over a year now since the R134 conversion and no more leaks and it blows good and cold.

 

If you need a vacuum pump and gauges let me know. You can borrow or I could help you.

 

Oh right... the R12 and R134 fittings are different. So if I want to retain the original R12 lines I'd need to adapt them to the R-12, correct?

I have heard sometimes R12 O-rings hold up. I have to learn where all the O-Rings are and see how I can replace them.

I'll have to figure that one out a bit more then.

Do you think using the new R134 compressor I'd need to discharge/ vacumm out the unit? I'll be sure to install the dryer as a last step before charge.

That's good news for sure. I haven't had AC since I broka a line alomost on day one when I purchased the vehicle. Mind you, I wasn't that bothered as the AC made the 3.0 even more gutless. But now I am looking forward to possibly getting this fixed before the 100 plus days start here in AZ.

 

Have you any AC experience? I wouldn't mind a hand once I get the parts I need. I am clueless when it comes to the R134 charge process.

 

Maybe I wasn't clear, I am also using a 3.4 compressor (R134).

 

hey elvota, have you made any progress with this? i'm particularly interested in your wiring solution. can't go much longer without it and i finally have all the parts.

 

One of the teachers from the community college (teaches A/C) and I are in the process of converting my R12 system to R134a. All he told me to get was the R12 to R134a fittings, which cost me about $6 each (need a high side and a low side). When we charge it we're going to put in 2 ounces of some high grade A/C oil that is designed for this kind of thing. My system's been open for quite a long time so there's no more R12 left in it so don't have to worry about having an R12 and R134a compatible oil. He hasn't said anything about O rings as it was my schrader valves that caused the leak. He also hasn't expressed much concern about moisture collecting in the dryer, but it wouldn't hurt to change it out.

On my 4runner the max amount of R12 is something like 1.9lbs, or was that the chevy we worked on that day, and a conversion table indicates that we should put in around 1.2 lbs of R134a. I'll have more exact numbers when we actually do it.

To make the A/C system perform like stock after converting you must install a larger condenser (in front of radiator) and a larger evaporator (in the cab). If you don't the A/C won't get quite as cold as it did from the factory, but it still works.

Hope this helps.

 

I haven't really gotten any further. I connected the lines and installed the compressor. Bought a new drier and have the grill off... but that's it.

I only have to drive about 1/2 hour during the heat of the day and haven't had AC for maybe 5 years now, so I am just used to it.

I will add some info to my thread when I make some forward progress.

 

And you keep telling me to save Money Steve!!

Ok back to our regulary scheduled trouble shoot! (I swear a 3.4 is in Tippy's futurte. I moved the engine like 4 feet the other day. Does that count??)

BTW steve got a really great friend that has done 5 swaps now and is involed with ORS so if ya still are stuck I'll pull in the beer favors (Meaning I now owe him a keg) and call him for ya )

 

I just have to put some time in to the figurin'.... just haven't had the motivation. One would think that 100 plus days would be all I need to get this figured out, but I just haven't had AC for so long I have trouble bothering now.

Usually, by the time I get fed up and swear to myself to get my AC sorted out... the temps cool off again and I just wait until next year.

 

So I am in the process of collecting the parts I need to do this. I have a old 3.0 compressor on the way for the connections, and a 3.4 compressor on the way to bolt up. My big question is electrical. What all do I have to do to get it to work. I have heard that the "a/c amplifier" is different polarity between the years. I have also heard I can pull the box/brain from behind the glove box and swap in a newer one.

Does anyone have any experience with this?

 

I've got my 90 4runner running great with my 3.4. Did it all myself including wiring, but my A/C isn't done yet. I'm in Sacramento and this is highly unacceptable. I kept the 3.0 compressor and all other A/C parts. I need help with the wiring for the A/C. If someone can please let me in on the secret wiring details for the A/C. I'm set up with a 96 3.4. HELP

4000 miles since July 08. Waiting to buy SC. Kick *ss seabass

 

Poor little fellow. What you got, 88 degree days?

Just giving you a hard time. If I can make it though a couple AZ summers complaining every day about my AC not working then I guess we all can.

Well, I still haven't really figured it out. Mind you, I haven't spent that much time on it either. I got the physical components all hooked back up... just no wiring. Now that it's cooling off, it will have to wait another 6 months.

By the way... aren't those 3.4's just to much fun to drive?

 

88 more like 108, but who's keeping track. I refuse to wait till next summer to try to figure this out. Call me stubborn. If anyone can help I'd appreciate it. In the meantime I will keep looking at these wire diagrams with cross eyes trying to decipher the secret code. ha-ha

 

Was your 3.0 an auto tranny? Because the 3.0 auto had an AC cutoff switch in case the engine coolant got too hot it would shut off the AC. The 3.4 ECU doesn't provide a signal to the AC to turn on that switch. It was only on the autos though. My AC cutoff switch has been bypassed.

 

Mt Goat--I've got a manual trans. So thats not going to be the problem.

Chris

 

I Had to run a new wire,from the a/c amp to the comp.It was a black wire with white tracer.I cut it at the amp and reran a new one to the comp.For some reason the old wire went directly to ground and fried one of my amps.Also I teed off that wire to run the factory fan relay.If the a/c amp will not turn on the comp at idle there is a turn knob on it that is glued so you cant turn it.It says RPM +- or something like that,cut the glue and turn it until the a/c comes on at idle.A/C has to be in working order for the amp to turn it on.
Bigblock

 

A/C is one of the many items on my list and I'm hoping to figure it out before the heat returns. I swapped the top plate from my 3.0 to the 3.4 and connected the hoses. Sounds like I have to change the fittings and clear the system of R12. Although I'll have to check my records cause I think the system was already set up for R134 prior to my ownership and the swap. It also sounds like I have to change the AC amp or just run a separate wire to it? This would me a good how to for those of us is warmer climates.