screamer76

well, i guess i need some help with getting my a/c going. this is very frustrating after getting this far; so close!

i've tried everything i can think of as far as the wiring goes, and i'm not getting anywhere. i have heard that the amplifier must be swapped out, but i'm not quite ready to accept that. there is a post by willcypher stating that once he did the tach mod, he was able to run his a/c without changing amplifiers. also, people like mt_goat and breknraj have a/c after doing the swap using the ORS conversion harness, and as far as i can tell, they didn't have to swap amplifiers either.

so, i have done the tach mod and everything seems to be alright there. the tach works, so the amplifier should be getting the signal from the igniter. i have connected the wire from the "act" pin on the ecu to the amplifier. i have also connected the wire to the magnetic clutch from the amplifier. that leaves me with the "ac1" pin on the ecu(12v), the lead from the efi main relay to the now missing ac idle-up vsv(12v), and the return lead from the ac idle-up, which goes to the amplifier. i have tried multiple combinations with the remaining leads, and gotten nowhere.

the a/c switch lights up, and the blower works fine, but i am not getting voltage to the magnetic clutch lead.

here are my a/c ewd's for both trucks
4runner ac_Part1.pdf
tacoma ac_Part1.pdf

help from anyone would be very appreciated. my girlfriend and my two year old are quite miserable with the recent heat and humidity here in AZ. i'm fine driving back and forth to work, but the lack of a/c is killing my desire to get offroad and actually enjoy the fruits of my labor.

please help!

mt_goat

That is correct, I'm using the 3.0 amp.

screamer76

yeah, that's what i thought. so there has to be a way to do it with the existing setup, and i'm just not seeing it. thanks for your input, mt_goat.

mt_goat

Yeah, there's a way but I don't know how. Mike's harness was ready to go with the current amp.

jasond

Try wiring up the a/c clutch to the idle up vsv on the amplifier, might not work but what do you have to lose?

screamer76

another 10a fuse

jokes aside, maybe i'll try that tomorrow; i'm alone with the boy tonight while his mom is at work.

are you talking about splicing the 12v lead from the efi main relay into the clutch circuit, because the black/red wire going from #6 of ih2 to #9 of the amplifier should be recieving a signal from the idleup, not putting anything out. the blue efi main relay lead to #5 of ih2 is a constant 12v. i tried hooking those two up to each other, but that didn't seem to work.

or were you saying to just hook up the 12v lead from the efi relay to the clutch leaving another amplifier lead unhooked?

these pdf's have a general description of the way the system works. they unfortunately leave alot to the imagination
4runner ac_Part2.pdf
tacoma ac_Part2.pdf

jasond

Oh, ok, i see the a/c amp on the runner controls the ground, sorry i didnt look at the ewd before i spoke. Well, you could do this, use that ground to control a relay that will send power to your a/c compressor--i would almost put money on that one.

Do this... get a general relay, run pin 86 and pin 30 to a switched power source (on with key), run pin 85 to IH2 pin 6 (the ground source for the idle up vsv) and run pin 87 to the compressor. Let us know how that goes, but im pretty sure that will work.


I am assuming you already tried IH2 pin 15 to the compressor, right?

screamer76

yeah, i've got the ACT wire plugged into the E5 plug for the 3.4 ecu
(ACT pin), and the clutch to amplifier wire(#15 IH2) is also connected.

i'm assuming the efi main relay lead(12v) and the AC1 pin on the 3.4 ecu
(12v) will work for the switched power source that you're talking about, since they're both constant voltage at least when i've got the a/c set to on.

can i pick up the kind of relay that you're talking about at checker or autozone?

mt_goat

Mike's harness used a relay for something, I don't know what it is for though.

jasond

The only pin from an ecu to run to this relay is the IH2 pin 6 on your runner harness (not the taco harness). If you want to get power from IH2 pin 5 thats ok, just as long as it has power all the time when the key is on. Dont use the AC1 pin from the 3.4 ecu, at least not going to the relay.

Yes, any auto parts or accessory store will have a relay you can use for this, even radio shack will have it. Its the same relay someone would use to install fog lights or something like that.

Also, you will need to disconnect the wire from the a/c clutch to the amplifier so that you can run it to this relay. I know that the old a/c amp box is supposed to send 12v to the clutch, but I dont know what would happen if you back fed the voltage into it.

Like I said earlier, I not certain it will work but I would try it on my truck (I would be trying it right now if my evaporator fittings didnt get twisted off trying to swap out the lines)

screamer76

. if it makes you feel any better, i broke the liquid tube for the evaporator( the one with the high port) when i was removing-destroying-my old battery tray. up until that happened, i had managed to leave the a/c pressurized.

will trying to set up the compressor this way leave it on whenever the truck is running, whether or not the blower is operating? if it works, will i have to put in a toggle switch or something to manually turn it on and off? will the evaporator freeze over if the compressor doesn't shut off periodically like it does with the factory setup?

sorry for all the questions. please don't take them as me second guessing you, because that's not the case at all. i just like to have all my bases covered.

jasond

No, it wont leave the compressor on all the time. What this is doing is turning the compressor on when the a/c ecu wants to turn on the idle up vsv, when the compressor would be on anyways. Since the a/c ecu controls the ground circuit on the idle up vsv, this has to be changed over to controlling the power going to the a/c clutch as the a/c clutch has a constant ground anyways (on the compressor itself)

If you had the compressor running all the time it would freeze over on the evaporator, thats why they cycle it in the first place.

screamer76

alright, i understand what you're getting at. thanks for your patience with my questions; i'm a little slow with new things, but i get there eventually.

i'll give it a shot. like you said, what have i got to lose? i'll try to pick up a relay today and possibly wire it up tomorrow after work.

odonekanobe

A quick bump to see if you have had any luck?

screamer76

well... i do have a/c now, but no luck as far as a permanent solution. what i ended up doing was running power straight to the compressor with a toggle switch to turn it on and off every few minutes. it's white trash, i know, but i did manage to do all of the wiring for it under the dash. you can't even see the switch unless you know it's there. so now i have two a/c switches. like i said, it isn't a permanent solution, but it will get us through the rest of the humidity. i've spent close to $200 with the broken line i had to replace, the idler pulley from the junkyard and then the evacuation and recharging, so as far as spending money on it goes, i'm done for this year. i'm going to continue to research and try different things, but it seems like my amplifier might be fried, because it seems to be getting all of the correct signals and just not sending any out . jasond's suggestion could be a good one, but i can't confirm that myself. the guy does seem to know what he's talking about, but his fix involves a working amplifier, which i'm not sure i have anymore. in any case, i will update this when i have a more solid solution, and as always, any input from anybody is welcome and appreciated.

and extra-special thanks to jason for his efforts; i'd love to know if anyone else has success trying it this way.

mt_goat

Yeah Jason is a Master tech at a local dealer here and has done his own 3.4 swap. He and Mike from ORS both were in Toyota tech school together.

screamer76

yeah, i'm pretty sure the reason that fix didn't work for me is the amp is toast. before i tried it, i got the system evacuated and charged and the guy turned it on to see if it would work. he said it kicked on and ran through a cycle, then shut off when he gave it gas to drive it back over to me. maybe it fried then, or maybe i fried it when i was trying to get it working by myself, i don't know. now i'm stuck with trying to figure out if i should bother with another '95 amp, or just go with the '00 . i guess it will depend on which is cheaper. i just wish there was a more conclusive way of testing the amp, not just the signals going to and from it. at least i can use it now. it's needed to be evacuated and charged since i got it, so it actually works better than it ever has for me. i'm planning on taking it out soon to see the difference offroad; i know i love the difference in town. i've got about 2000 miles on it with no issues other than the a/c.

jskijoe

mt, where is the amp you are referring to? And should I have the one from the donor? I'm trying to keep my R12 system since I don't have everything a/c wise from the donor and hopefully I'm able to keep it simple. Thanks

mt_goat

I guess its behind the glove box, I never did anything with it. It's still in place where ever the factory put it. No, I didn't keep anything from the donor truck for the AC except the compressor.

screamer76

once you have your glove compartment removed, your cooling unit is exposed. at the top of the front side of the cooling unit is a small(9 wire) harness connection, which is plugged into the amplifier.