Current Classifieds

Drivers side door panel Orange
Date: 05/22/2018 01:54 pm
2.3/C-4 torque converter needed
Date: 02/08/2018 02:26 pm
1971-1975 Pinto
Date: 01/09/2017 04:14 pm
Seeking parts
Date: 10/18/2020 10:35 am
1975 Pinto wagon emissions decal wanted
Date: 09/20/2018 11:01 pm
Need seals Pinto Wagon
Date: 02/16/2017 05:09 pm
2.3/C-4 torque converter needed
Date: 02/08/2018 02:26 pm
Wanted instrument cluster lens for 74
Date: 04/30/2023 04:31 pm
1979 Runabout Rear Panel
Date: 01/04/2020 02:03 pm
73 actuator for heater blend door
Date: 09/19/2019 04:43 pm
78 wagon instrument y
Date: 04/30/2018 07:41 pm
74 & Up Parts
Date: 01/20/2021 03:22 pm

Author Topic: Idle air control signal, turbo swap, a/c  (Read 1611 times)

0 Members and 1 Guest are viewing this topic.

Offline denmach1

  • Pinto Member
  • **
  • Posts: 25
  • FeedBack: +0/-0
  • Another Pinto Driver

  • Total Badges: 2
    Badges: (View All)
    Topic Starter Windows User
Idle air control signal, turbo swap, a/c
« on: August 18, 2014, 05:36:59 PM »
I am in the middle of a turbo swap into my 77 Cruisin Wagon using a LA2 ecu. I am also installing a vintage air system. Does anyone know what type of signal I need to send to the ecu to adjust the idling when the compressor turns on? (voltage? ohms? which pin? etc...) Any help is greatly appreciated.

Offline Wittsend

  • Pinto Master
  • *****
  • Posts: 2499
  • FeedBack: +241/-0

  • Total Badges: 8
    Badges: (View All)
    Tenth year Anniversary Mobile User Topic Starter Poll Voter 1000 Posts Linux User Windows User Fifth year Anniversary
Re: Idle air control signal, turbo swap, a/c
« Reply #1 on: August 18, 2014, 06:58:49 PM »
As best I can recall an LA-2 and and LA-3 are direct swap ECU's. My Pin Out for an LA-3 shows:

 10 = A/C clutch - A/C input

54 = WAC  WOT (wide open throttle) A/C cutoff

There were also two fan control signals one of which might be relevant to the A/C:

52 = HEDF Highspeed Electro-Drive Fan

55 = EDF    Electro-Drive Fan (low speed)

Hope this helps. At the moment I don't have the "type" of signal sent only where they are going/coming from. Are you using the factory relay box?

Offline denmach1

  • Pinto Member
  • **
  • Posts: 25
  • FeedBack: +0/-0
  • Another Pinto Driver

  • Total Badges: 2
    Badges: (View All)
    Topic Starter Windows User
Re: Idle air control signal, turbo swap, a/c
« Reply #2 on: August 18, 2014, 07:11:54 PM »
Wittsend, thanks. I am using a Vintage air system and its controls. I see the a/c input on pin 10 of my diagram but just not sure what kind of signal to send to it. I can easily send 12v to it when the clutch is engaged but i need confirmation that that is what it needs. I don't want to fry anything

Offline oldkayaker

  • Pinto Master
  • *****
  • Posts: 758
  • FeedBack: +114/-0
  • Gender: Male

  • Total Badges: 5
    Badges: (View All)
    Topic Starter Signature Windows User Tenth year Anniversary Fifth year Anniversary
Re: Idle air control signal, turbo swap, a/c
« Reply #3 on: August 19, 2014, 12:44:42 PM »
The 87TC EVTM shows the LA2 pin #10 connected to the +12V side of the A/C clutch coil.  Note there is one of those surge protection diodes in the wiring harness connected across the A/C clutch coil to moderate the voltage spikes.  I believe this #10 pin is the circuit that opens the IAC a little to maintain idle speed when the A/C is on.
Jerry J - Jupiter, Florida

Offline denmach1

  • Pinto Member
  • **
  • Posts: 25
  • FeedBack: +0/-0
  • Another Pinto Driver

  • Total Badges: 2
    Badges: (View All)
    Topic Starter Windows User
Re: Idle air control signal, turbo swap, a/c
« Reply #4 on: August 19, 2014, 08:10:40 PM »
Thanks for all of the great info guys! This build would be a real struggle without this site and all of your knowledge and help.