PROBLEM SOLVED, CHECK POST #25

Hey guys,

A little while ago I posted up an SC400 with an Aristo 2JZ swap that I did. Everything is working great except for the a/c. For some reason the clutch will not come on. Now I've checked out all the wiring and whatnot, and there are two wires that go to the ECU that have to do with a/c. ACMG, which grounds the a/c clutch relay, and AC, which is supposed to receive a signal from the a/c control unit in the dash.

If I run a 12v signal to the ECU on the AC wire, then the ECU grounds the relay via the ACMG wire and the clutch kicks on. But for some reason the a/c control unit the dash won't send out that 12v signal.

I put R134 into the system and I even jumped the pressure switch to see if that was the problem, but even with the pressure switch jumpered I never get that signal at the AC pin. I also ran the a/c trouble codes and the system shows no codes.

I know a lot of you guys have done this swap (many of which I've personally wired up for you!) and I haven't heard of this problem before, anyone have any ideas? Thanks!

-Doc

 

 

Sorry about that

 

^^ Duh dr tweak, its a performance swap problem! Hope you figure it out. Have you tried using a different A/C relay to see if yours is bad?

 

We can make the text below the forum index title a little bigger if ya want.

 

No, the whole relay side of the circuit is working properly, the ECU can and does turn the relay (and therefore the clutch) on via the ACMG pin when it gets a signal on the AC pin.

-Doc

 

Okay.... is there anyone running a/c with an Aristo 2JZ swap?

-Doc

 

I am having the same issue on my swap
I read someone posted that a high sensitivity relay needs to be wired in .5amp to make the system active, but no where on to wire this in or on what wires. I am assuming this relay will send the 12v sig to the ac wire but which signal wire from the ac unit i have no idea.

BTW thanx again for the harness, car runs perfect other than this

 

Yeah we need to get this sorted out. Anyone know more about this "high sensitivity relay"?

-Doc

 

i got the same problem on my 1jz swap... still cant figure out yet..

 

I've heard you just make a manual toggle switch for the clutch to come on. Thats the only solution I've heard of right now.

 

How? Thays funny because i did like 3 of these swaps already and never had that problem.
As for the ac issue with the aristo ,i'll ask my boy about it. He has done tons of aristo swaps.

 

what output is the ac unit putting out. a normal relay triggers on milli amps so if wired correctly it should work.

 

It only sends out milliamps but it's still 12v, right? Because there's no signal at all coming from the AC unit when I measure for voltage. Is the A/C in your SC400 working?

-Doc

 

as you know because i just heng up with you, no driving SC400 yet. maybe today. so let me understand this. there is no output from the control unit. can you use something else to trigger it out of that unit.