sgib07

I have just done this swap in my 4runner and got 3.4 amp and had wired it in.
Well it appears that the air conditioner amplifier i got may have been the wrong one or model as i have just had the air con regassed and after the auto elec and i went all through my wiring with the diagrams we couldnt find any problems..... just the air con wont kick in.
I dont know if the amps differ between models but neither of us could see why it wouldnt work. The only other option is that the amp is stuffed as well.

So in the end we are ditching the amplifier and hooking up a thermostat and relay to control the air conditioning instead.

hamish_18

I am doing the wiring tomorrow. but I haven't gotten the correct clutch yet as I am using all 3.0 stuff for the AC. I saw that you can just replace the clutch to the 3.4 one and be fine. I planned on waiting on the wiring as its still to cold here to worry about it. So if we could get a good answer to what needs to be wired where for the 3.0 stuff that would be freaking sweet.

GJCruiser

I wired the 3.4 amplifier this weekend. I'll have the system charged and report this week.

GJCruiser

Just returned from the shop where the A/C was evacuated and recharged with R134. The system blows cold at 40 degrees. If it helps, this is what I have and what I did.

1993 chassis and 1999 4Runner donor.

I removed the A/C amplifier with attached thermistor from the 3.0 and replaced it with the new assembly from the 3.4. The 3.4 circuit card sits in the "drawer" where the 3.0 card came from and the thermistor goes back trough the plastic at a seam and reclips inside to a central fin.

I cut the 3.0 plug end from the chassis harness and reattached the 3.4 plug end cut from the donor. There are eight wires there. That plugs onto the amp.

Then I found those wires at their other end in the kick panel and wired in the same fashion as the rest of the conversion. (You know- C1-20 goes to II3-25, and so on).

Hope this helps.

GJCruiser

For what it's worth, the shop charged two hours labor and with dryer, conversion kit, etc. the cost is not cheap!

I asked them about the web statements such as "R134 won't stay in a R12 system". Their response was that happens when one uses the old compressor as the 134 seems to eat them. Considering the cost of the conversion, if you have both compressors lying around, you may think about using the 3.4.

dntsdad

I have a couple questions.

1) What is a "conversion kit"?

2) Any chance that you can post exactly what wires you connected, joined, didnt use? A schematic in a sense while its still fresh in your mind.

GJCruiser

I had to buy what was called a R134 conversion kit. It included new o-rings and service "tees" which allow the R134 equipment to connect. They are different from the R12. I'm at work, but when I get home where the schmatics are, I'll post up.

GJCruiser

Forgot to mention, a new dryer is added as a sealed unit off the shelf and installed directly before resealing the system closed. As I understand it, the dryer is kind of like the kidney where thing collect over time like old R12.

sam4runner

iTrader: (1)

I am curious about something. Does the compressor and a/c system have to be charged for the clutch to engage? I am doing the wiring for it and i can't get the clutch to engage when i turn the a/c on? The system is drained, would this be the problem, or just my wiring? or does the clutch only engage when it is needed, not right off the bat. Thanks

jviers

The AC system has a low-pressure cut-off switch which does not allow the comp to engage if there is too little pressure in the system (freon low or system empty of freon). I don't recall where this switch is at the moment but it will be somewhere near the firewall on the larger hose. The AC system has two parts, a high pressure leg and a low pressure one. The low pressure lines are larger and travel between the evap under the dash and the comp suction side (the end from the firewall); the high side flows from the comp to the condensor in front of the radiator, and back through the small line to the firewall. Trace the hose on the low side and you should find a switch in the line somewhere. If you jumper that switch connector the comp will engage even if there is no freon. I'll look later and post any locations I find or corrections....
I'm at the AC point in my conversion (Tucson, AZ--AC is a necessity now that I am older and softer).

sam4runner

iTrader: (1)

Hey Gj any chance on getting you wiring you did for the A/C?