How to make AC work with your swap, aka: Need help with AC wiring thread Options

[lagos]

ok... so my AC hasnt worked since the swap and i figure now is a good time to wire that crap up. so i have my harness apart and im trying to look at the wiring diagrams to figure out a few things. seems like i need some help.

"ac amplifier" in the diagrams means the main AC compressor, correct?

on it, is a plug called A8 (looking at the 5sfe diagrams). the harness goes from there to a plug called IM1 and then 3 wires go to the ECU's 1st plug. where is IM1 located ? is it the white, 5 wire plug that goes from the 3s hanress, and plugs in right behind the glove box?

This post has been edited by lagos: Jul 29, 2006 - 9:02 PM

[lagos]

i finally found my wiring book. IM1 seems to be the correct plug that i was looking for.

dustin corrected me by telling me the AC amplifier is a large unit behind the glove box and not the main ac compressor that bolts to the motor.

after looking around some more... i belive the AC compressor is labled as "A/C magnetic clutch". and it the harness plug on it is called A2. can anyone verify this?

[MaskedMan]

I think the plug is called A4 (A/C magnetic clutch and compressor sensor) should have 4 wires, and is a grey connector.

[lagos]

yeah, your right. on a 6th gen they call it A2 and on a 3s harness its called A4. thanks for clearing that up.

now.... here is my next qestion. if you were to take the 3sgte harness apart...and trace the wires coming from the a4 plug. where would they all end up?

for example... plug a4, pin 4 is a blac/white wire . this is the main power wire that engages the AC cluch. in the 6th gen, this goes to the main fuse box plug EA1 pin 10. where does it normally go on the 3sgte? im guessing it would go to one of the 2a,2b,2c fuse box plugs that used to be part of the original harness, but what one and what pin. and what about the rest of the 4 wires? where do they get routed to on the original 3s harness?

i cant find any 3s wiring diagrams that have the AC system in them. my book dosnt even metion the AC.... odd.

[lagos]

ok ... i think i figured most of it out...

on the 3s harness they go from:
a4 plug on the compressor.... 3of the 4 wirles go through the fire wall to a plug called IH1 and plug behind the glove box. but that plug wont work for our car, so we have to rewire the IM1 plug in.

and the 4th black wire on A4 goes to one of the fuse box plugs?

This post has been edited by lagos: Jul 18, 2006 - 4:32 AM

[MaskedMan]

well the Black-White wire from A4 goes to a splice point. one end goes to grey connector E7 pin 10. the other end goes up to another splice point. one goes to A/C magnetic clutch relay pin 1. and then other end goes to A/C condenser fan relay NO.3 pin 2. Those are both located in the relay box 5.

the Yellow-Black wire from connector A4 goes to a connector called IH1, pin 3, from there it goes to A/C amplifier connector A17 pin 5.

the White-Blue wire goes to the connector IH1 pin 5, from there, it goes to connector A17 pin 9.

The White-Red wire goes to IH1 pin 4. then to a splice point. one end goes to A17 pin 14. The other end goes to A26 pin 1. this is a 4 pin connector. A/C Thermistor

Pin 2 of A26 goes to A17 pin 16 and is a Yellow-Green wire.

Pin 3 of A26 is a yellow wire, and goes to connector IJ1 pin 5. from there it goes to a splice point. It then splits off and both end connect to other splice points.

I will describe one first..

one side leads to another splice point and then goes to A/C room temp sensor A23 pin 2. then A23 pin 1 is a White-Red wire and goes to connector IQ1 pin 7, then goes to AUTO A/C AMPLIFIER A34, pin 5. the other splice goes to connector EA1 pin 5, which then leads to A/C ambient air temp sensor A1, pin 1. then Pin 2 of A1 is a Yellow-black wire. it goes to connector EA1 pin 4, and then to connector IQ1 pin 1, and from there goes to AUTO A/C AMPLIFIER A34 pin 6.

OK now here is the second one....

Goes to connector IQ1 pin 2, and then goes to splice point I11 where it goes 3 ways. One way is a purple-white wire, that goes to A34 pin 15. Another purple-white wire goes to connector IQ4 pin 14, from there goes to A/C control assembly connector A18 pin 7. (this is a 25 pin connector)

The splice point I11 also has another yellow wire that lead to another splice. The yellow wire then goes to AIR MIX CONTROL SERVO MOTOR, A29 pin 3. (this is a 6 pin connector.) the other wire coming from this splice point is a Orange-black wire. This goes to the A/C water temp sensor A27 pin 3 (this is 4 pin connector). Then pin 1 is a Red-Green wire that goes to connector A34 pin 20 (Auto A/C Amplifier)

and thats it i think.. unless you want to know how the Air Mix Control Servo Motor A29 is hooked up.

This post has been edited by MaskedMan: Jul 18, 2006 - 4:36 AM

[lagos]

awesome! airconditioned car, here i come! haha

now, one more question, just so that i can doubble check everything to make sure the colors didnt change from 5th gen to 6th gen. can you tell me the function of each of the 4 wires coming off the AC compressor? i know the black/white one, but im not sure about the rest.


Black-White = ac magnetic clutch power
Yellow-Black = ?
White-Blue = ?
White-Red = ?

[MaskedMan]

oh sorry i forgot to put where the 4th pin of the A/C thermistor A26 goes. its a green-red wire that leads to connecter IJ1 pin 6 (18 pin connector) then leads to Connector IQ3 pin 3 (8 pin connector) and then it leads to pin 19 of A34 (auto a/c amplifier)

As for what those wires do exactly... ill have to find that out. all i know is that the both the white-blue wire and the white-red wire should have continuity with a/c switch (a/c control assembly) on and ignition sw at on position. I will see what else i can find out.

[lagos]

awesome, you rock

[lagos]

chrisD from ctech was able to hook me up with the diagrams for the alltracs AC system!

http://www.celicatech.com/vfewdsou/1990/90.../ATmaairpus.pdf

[MaskedMan]

oo nice, I was just going off my own alltrac, and the difference from my alltrac and that diagram right there is that mine has Auto Air Conditioner push type control, and that diagram is for a Manual Air Conditioner push type control. I wasn't sure which one you wanted since the 6gc is manual, and the Alltrac is auto (but idk if all alltracs were auto). Just to point out a difference in EWDs There is also Auto Dial type control, and Manual Dial type control EWD. So i was kinda confused on which to use, but now you have a lot of information to go by

[lagos]

alright.... one more quick question. seems the AC wiring has changed in 90. 95 and 98 in the celica . why? who the hell knows.

the AC has a plug (A4) with 4 wires on it.
pin numbe 3's function is labled as "VC" . what does this DO? whats its function inside the AC compressor?

the reason why i ask, is that in a 95 celica, you would hook this up to plug IM1 pin 3, and the it would go to the AC AMP. problem is, this they removed this pin from the 98 IM1 plug and its function (MGV?) dosnt seem to exist on the AC amp! im guessing i can just skip this wire... but i want to know what it does, before i eliminate it.

This post has been edited by lagos: Jul 18, 2006 - 9:08 PM

[MaskedMan]

hmm... ok 2 wires should be to activate the magnetic clutch. And im guess the 2 other wires are sensors? I know there's this one sensor that reads if the compressor is spinning. This will help protect the compressor if there is something cuasing the compressor to be stuck.. But the thing i dont know, is if it's on your car, cuase they did eliminate this later on. Hmm, ill try to find out the name of this, cuase i can't remember, but i'll prolly have time, since my flight is going to be crazy delayed. stupid LAX airport has no electricity.

This post has been edited by MaskedMan: Jul 18, 2006 - 9:18 PM

[lagos]

cool ... if you find out all the functions of the 4 pins on the AC unit, let me know. i like to know what is doing what and why.

now for some good news. everything should be wired up and "in theory", i should have AC again (after i get the system blead and recharged).

i lucked out, because i kept my 5sfe compressor, instead of the 3sgte one. i unpluged the 4 wire plug from it and looked at the pins..... only 3 pins!!! so whatever function they removed from my 98 ac amp, is also not in compressor, so i shouldnt have any issues there. tomorrow, ill plug everything back in and run some tests with the multi meter to make sure everything is wired up correctly. then ill take the car in for a recharge.

on a related topic... man this weather sucks. i couldnt work on the car at all during the day because of the 100+ deg weather. so i wait till night time, and as soon as i get in the garage, we get this huge thunderstorm...lol . i have all this little stuff i want to do before the meet but at this pace, i dont know how much ill be able to get done.

next project is to figure out why my ABS stoped working after the swap.

[MaskedMan]

OOO nice, your 98 compressor should be better anyways. . ill try to figure out what does what when i get home. Is it really that hot up in the EC right now? wow, i remembered it being cooler than here in Cali haha. Haha i think im going to fall asleep at the airport. haha i was up all night looking at the Celica EWDs hahaha. It would be nice for you to have A/C again, A/C is nice, i should be getting my A/C certificate or whatever sometime soon, so i can legaly work on A/C systems , it's just that the course went by so fast, we didn't get to cover wiring much, just mainly the mechanics of it and how to service it. Ugh i just wanna get back home already, haha all this waiting and not being able to work on my car is like killing me haha. Goodluck with your A/C, if you use your stock compressor, cant you just hook everything up the way it says to hook it up in that 6th gen celica EWD?

[lagos]

if you use your stock compressor, cant you just hook everything up the way it says to hook it up in that 6th gen celica EWD?

thats the basic idea.... but you are now using a 1990 3sgte harness. so you have to rewire where the AC gets its power from to engage the magnetic clutch , comunicates with the AMP, and then rewire the signals the AMP gets from your 3sgte ecu (Ac1, ACT, and imput from your ignitor).

This post has been edited by lagos: Jul 18, 2006 - 10:45 PM

[lagos]

ok.. i figured out the functions of the 3 wires that go to the AC unit

pin 1 =SSR+
pin 2 =SSR-
pin 3 = MISSING n/a
pin 4 = MG+


ssr + and - and the speed sensor that only allows the AC compressor to turn on when it detects that the Ac compressor is spining. like you said above, this is a safety feature to make sure the magnetic clutch wont engage if the drive belt breaks or something.

MG+ is the main power for the magnetic clutch.

edit: i doubt anyone else cares about this thread, but this should be some good info if anyone finds it in the futue.

This post has been edited by lagos: Jul 19, 2006 - 1:19 AM

[MaskedMan]

haha nice, i was just about to give you the same info haha. cuase i was reading the Celica EWD on the plane, and i read that PIN 3 was excluded on the 5sfe. I hope you get your A/C working soon! Oh and i read about the ABS as well and yeah, your going to have fun with that haha.

[WannabeGT4]

edit: i doubt anyone else cares about this thread, but this should be some good info if anyone finds it in the futue.

I care. Especially since the last few days have been 105+ I will not be going without AC once my swap is done.

[phattyduck]

I'm also curious as to why there was any rewiring of the A/C system?

For my swap, I left all my A/C wiring stock (along with keeping the stock compressor). At that point, all you need to wire up are the couple wires that go to/from the ECU related to A/C idle up and A/C cut...

Without even hooking those wires up, I get A/C - just no idle up (I only use it on the freeway at the moment) and no A/C cut (turn it off before full throttle).

I looked into swapping over to all ST205 stuff, but putting together that mish-mash of parts and wiring looked like it was going to be hell.

-Charlie