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Can't believe this is so easy and I've never even done it! Still without ac after 4 swapped years in central California where it's over 100 from May to September......everyday just about. One dang wire!? I read this thread a long time ago but never came back to it.
Anyway, this is all accurate for the 1st gen runners as well? Doing a swap into an 88 and old like the ac to work. Never saw anything in here except 3rd gen trucks so I would assume 2nd gen runners as well.
Just magnetic clutch wire from ECM to body harness connection?
I know absolutely nothing about ac except that I want it working.
I have a 1985 4runner with a 2001 3rz but the ECU has the same AC1(blue/yellow) and ACT wires. If you ground the AC1 wire the engine will idle up (although not as much as the older trucks). My 1985 AC amplifier has a blue wire coming out of it that originally went to the 22RE ECU and the ground side of the idle up VSV. The wire is found (in my 85)in the same plug the black/white AC clutch wire is in. I connected the blue/yellow (idle up)wire from the 3rz ECU to the blue wire from the 85 AC amplifier using a 3k ohm resistor between the two and it has been working properly so far. If you hook these wires together without the resistor it will idle up all the time. The idle up function on the newer Toyotas is much less pronounced than on the older models almost seamless as when you turn on the ac the idle reacts by holding steady instead of jumping up. hopefully the 3.4 reacts to the 3k ohm resistor mod the same.
I have a 1985 4runner with a 2001 3rz but the ECU has the same AC1(blue/yellow) and ACT wires. If you ground the AC1 wire the engine will idle up (although not as much as the older trucks). My 1985 AC amplifier has a blue wire coming out of it that originally went to the 22RE ECU and the ground side of the idle up VSV. The wire is found (in my 85)in the same plug the black/white AC clutch wire is in. I connected the blue/yellow (idle up)wire from the 3rz ECU to the blue wire from the 85 AC amplifier using a 3k ohm resistor between the two and it has been working properly so far. If you hook these wires together without the resistor it will idle up all the time. The idle up function on the newer Toyotas is much less pronounced than on the older models almost seamless as when you turn on the ac the idle reacts by holding steady instead of jumping up. hopefully the 3.4 reacts to the 3k ohm resistor mod the same.
Thanks for your input. Maybe somebody can verify this. I might try it once my poor truck gets a new motor :-( :-)
Does anyone have issues while using the original 3.0 a/c setup where the compressor sits to far back?
the swaps in but the a/c compressor pulley doesnt line up with the crank etc so the belt will always pop off after one turn.
An addenduum to this posting.
I did not want to have a half-assed operating A/C system so I just grafted in the late model amplifier and grafted the cables together. I removed the 4WD idle cut relay (not needed) and I am using that to operate my sol. #4 in the transfer . No wasting good parts.
I just encapsulated the smaller amp board in anti-stat, high density foam and shoved it back into the little cubby that the original sat in.
Now I can have the added benefit of the proper idle-up speed and it works just dandy.
Nothing to make, really. Scour the junkyards, pull the wiring pigtail from the newer one and graft it to your existing one. Find any fairly dense foam material to hold it steady and, viola!
I have a 1991 Pickup that was originally R-12 and a 3.4 out of a 1998 4Runner. I tried several things (swapping pullies, etc.) When finally I stared at it for a few minutes and just swapped the top plate from the 1991 compressor over to the 1998 compressor then just wired up the A/C clutch.
And BOOM! A/C worked great on a 550 mile trip from Denver to Kansas City in August. The dog sure was happy about it!
And as an addendum to my earlier posting in this thread, I was not happy with the temperatures I was seeing out of the center vent. Never got colder than 50 degrees. That just aint gonna cut it. Because I implemented the use of the later model 4Runner A/C amplifier board it as designed, IMHO, to err on the high side temperature-wise. This, I am sure, was built in to the calculation to cycle the compressor more often and, at a higher temperature away from 32 degrees, to keep the evaporator from freezing up. also, thermistors do drift a bit especially after they age a while so it only made sense that this one was not where it should be. Toyota used a pretty basic NTC thermistor with a fairly close asymptotic curve that would range between 1.5K and 5K Ohms. 5K being ~32f and 1.5K ~77f. So, in order to close it in a bit tighter to the freezing point I decided to "fool" the amplifier by giving it a different reading than that which was being sent from the thermistor. Basic electronics states that in order to DECREASE resistance to a given number you need to apply another resistance in PARALLEL within that juncture. So, I grabbed a single turn, 100K pot from my junk drawer and just piggybacked the thermistor. I started driving down the highway after the system was stabilized and started tweaking the pot by increasing the resistance thusly noticing the vent temps coming down immediately.
Taking in consideration the thermal loss between the cooling unit and the center vent it should have been in the neighborhood of 3-4 degrees. I stopped when I got the vent cycling between 34.5 to 41 degrees. Since I live in a very dry climate I am not too concerned with evaporator icing so this is a good reading to maintain. The system will not cycle nearly as much as it did prior so that is a benefit.And if I am traveling somewhere more humid, and it starts to exhibit freeze over than I can dial it back a tad as I have the pot poking through a hole inside my glovebox.
Summer is almost here and now I can enjoy it better.
Any idea what plug the AC magnetic clutch wire is at for 1996 T100 auto? I've seen the ACC and ACT but haven't been able to locate the magnetic clutch on the diagram. Thanks!
Hello, Im trying to follow your directions, I built my own harness stripping the 3VZ plugs and 5VZ and then re-pinning everything. the way I understand the logic. On my 93 4 runner. the Magnetic clutch is coming from the amplifier through IH2 pin 15. so when I rebuilt my harness, I used the 93 plug (because it fit in the body harness) and put the black/white wire back into IH2 pin 15. I checked continuity from IH2 pin 15 to the little round plug that goes the the compressor and its good.
what am i missing here? I dont have ACT, AC1 or ACV hooked up at all. Both cars were 5 speeds oh by the way, my donor was a 95 T100. its AC also had the same single wire plug to the compressor
...update....
i put 12V straight on the compressor plug and the clutch does engage, however im not getting cold air out. im using the original compressor, just changed the pulley. never opened the system
*****update update**** i figured it out. in the process of the swap, and flexing the rubber AC hoses, i guess they were just old and formed a small leak. the system drained. I replaced the hose and recharged. all good!!!!
so since I built my harness, I kept the AC line in IH2 pin 15 and dont have ACT or AC1 or ACV hooked up.
Mine is wired exactly the same way. Matched up the magnetic clutch wires when repinning the harness. System has a good charge on it as well. Still can't get the ac clutch to engage though. Any ideas? I have also tried grounding the pink wire as well seeing as my truck was originally an auto. No results. For the ACC and AC1 wires have to be eliminated for this to work?
Hoping to get AC soon. It's gonna get hot and I've been driving this thing for a year and a half without it. Thanks!
Last edited by Goddamnboh; 05-14-2017 at 11:45 AM.
I haven't had a/c since I did my swap about 14 years ago. Decided it's time so when I was having a local shop install my URD 7th injector setup I asked them to connect the a/c wire. All the other a/c components needed replaced so I wasn't expecting to have a/c leaving the shop.
I finally got around to replacing every component and pulled a vacuum that held so I went to put a charge in it. THe only way I could get the clutch to engage was jumping it to the battery directly. I was hoping it was not engaging because the pressure was too low. I now have a full charge in it and still cannot get the clutch to engage. I tried jumping the pressure switch to rule that out and it does not engage.
Am I correct in that the only thing I have to do is connect that one wire to IH2, pin 15 and it should work? My harness was done by my friend 14 years ago and to be honest is a source of embarrassment. I wish I could start all over with an original 1993 harness and purchase a conversion harness.
I had my magnetic clutch wires routed right, but ended up having a bad AC amplifier on my 94. I believe the signal the goes through the pressure switch and amplifier first, so maybe check those components if you're not getting the clutch to engage. Also l fan speed can't be on OFF. Sounds simple, but often those things are overlooked. Hope that helps!
What is weird is the wire to the magnetic clutch runs directly from the clutch, through the firewall and into the wiring loom. Maybe my harness was missing the a/c connection?
This was a super helpful thread, thanks to everyone who put up info on wiring A/C. Just wanted to add that for my application - 1990 Toyota Sunrader RV 3VZE to 2004 Tacoma 5VZE manual swap, I needed to hook up two wires. One was the B/W wire from AC Amplifier in the body harness to the green wire in the engine harness that goes to the magnetic clutch. I also needed to wire the black Igniter/Tach wire in the body harness that goes to the AC Amplifier to the G/B wire in the engine harness that comes from the igniter. At least on my truck, the AC Amplifier needs to see an RPM signal before it will engage the magnetic clutch. Just FYI.
I've been trying to figure how to complete the a/c swap in a T-100
I'm helping a friend swap a 3.4 from a 1995-96 T-100 SR5 4x4 5 speed to his 1993 T-100 DX 4x4 5 speed. The newer powertrain and wiring harness had already been swapped in another 1993 T-100 SR5 5 speed which my friend bought complete for the swap. That one lacked a/c but the DX that's getting the new motor does have it. It's an early 1993 but but it came with R-134 from the factory unlike my 1993 pickup that's a few months newer but still had R-12. I've read that there were some wiring differences between R-12 and R-134 systems in compact pickups but I guess it's not the case for this one since it never had R-12 in!
We swapped the whole wiring harness which came from the 1995-96 with the OBD2 connector.
We managed to replace the compressor and I did replace the dryer, vacuumed and recharged the system but the compressor still won't get power when I turn on the switch on. The black and white wire that energizes the a/c clutch has continuity from the 10 wire connector of the new harness that connects to the evaporator box to the compressor plug but I noticed that the newer harness has less wires than the original. I did check the continuity for the low/high pressure cutoff switch on the evaporator box and it does have enough charge to start the system so I think there must be something that changed and that the A/C amplifier must need to be wired differently or replaced.
I'd like some advice on that.
here are a few pictures of the old connector on the 1993 wiring harness and the new one with less wires on the 1995-96 (I don't know which year but the computer's number seems to match the 1995-96 models). If I understood correctly, there might have been a new A/C amplifier used in 1996.
Here's the plug from the 1993 T-100 harness I removed. Just the two pins on the right have no wires in.
this is the newer plug 1995 or 1996 T-100 that was unused in the previous installation on a non-a/c 1993 T-100. Wires are on different locations and just 6 wires instead of 8.
Of course there was no a/c amplifier to match with this connector in the no a/c T-100 and I can't find the wiring information for the 1995 version.
Any help would be appreciated, I've read a lot of stuff but I'm getting confused now! And not a lot of information on the T-100 vs 4Runners or compact trucks from the same period.
07-28-2014, 10:10 PM
