Go back to home

gen2-gen3 elec conv AC issues?

Author
Post
Essentials Only Full Version
just_ace
Moderator
  • Total Posts : 2508
  • Scores: 89
  • Reward points: 4598
  • Joined: 2011/04/07 19:51:15
  • Location: perth wa Australia
  • Status: offline
2012/06/15 13:50:09 (permalink)
0

gen2-gen3 elec conv AC issues?

my st185 (norm gen2 3sgte) is fitted with a gen3 engine and ecu setup using a berk patch loom. the AC no longer works, the signal isn't being sent to turn on the AC mag clutch. i think i've prtty much figured out why and the difference between the gen2/3 setups.
 
just wanted to know and confim if others have come across this issue and sorted it?
 
AFAIK, the gen2 earths the signal from the AC MAG clutch relay at the AC1 pin (BGB says you should have 12v between pins AC-E1 with IGN and AC ON)
 
where as the gen3 sends a signal from the AC1 pin to the AC ecu which inturn earths the mag clutch relay (theres no voltage check to be done according to the bgb for the gen3 ecu between E1-AC1)
 
i'm going to cut the AC wire on the patch loom and see what V i get from both ends etc and report back, but i'm guessing i'll get 12v from both with IGN and AC ON, which will mean i'll have to fit a relay between them with the gen3 ecu sending a signal to earth the incoming AC wire from the AC MAG relay...? is this how one "reverses polarity?"
#1


3 Replies Related Threads
    Mrskylighter
    MR2 Deity
    • Total Posts : 2156
    • Scores: 174
    • Reward points: 6592
    • Joined: 2011/04/07 19:51:15
    • Location: NSW Australia, Hills District
    • Status: offline
    Re:gen2-gen3 elec conv AC issues? 2012/06/15 13:58:31 (permalink)
    0
    I had this problem in the past using an AP Power FC on an early gen2.
    I solved it with a simple relay and some wiring.
    Let me think how I did it and get back to you.
    #2
    just_ace
    Moderator
    • Total Posts : 2508
    • Scores: 89
    • Reward points: 4598
    • Joined: 2011/04/07 19:51:15
    • Location: perth wa Australia
    • Status: offline
    Re:gen2-gen3 elec conv AC issues? 2012/06/15 14:28:41 (permalink)
    0
    cheers. small update.
     
    i cut the wire and with a little test light pen connected to chassis earth tested what happened with engine running and AC on.
     
    earthing the wire going from ecu dropped the idle which i assume meant the AC mag clutch kicked in. however the AC light on the dash started flashing also.
     
    earthing the wire from the loom achieved nothing, so i guess that wire needs to be powered in the gen2?
     
    so i think i need to set up a relay which sends power to the AC ecu while at the same time earths the eng ecu pin(AC1).
    #3

    nissky
    MR2 Aficionado
    • Total Posts : 285
    • Scores: 11
    • Reward points: 1854
    • Joined: 2011/04/07 19:51:15
    • Location: Sydney, NSW
    • Status: offline
    Re:gen2-gen3 elec conv AC issues? 2012/06/15 14:35:59 (permalink)
    0
    I had a problem with my swap, which was fixed by removing the ACT pin (pink/grey) going to the AC amp. This was stopping the the AC amp from turning on the AC clutch.
    What i found on my car was that the AC amp, has control over the AC clutch.
    The engine ecu had control over idle up and via ACT pin could tell AC amp to turn off AC.
     
    I now have the idle-up controlled via AC amp (spare VSV pin), and no override ACT pin from engine ecu.
    Looking at wiring diagrams its halfway between gen2 & gen3 setup.
    post edited by nissky - 2012/06/15 14:48:00

    Carless again :(
    #4
    Jump to:
    © 2025 APG vNext Trial Version 5.5