AC Wiring for MS3 Gold Box

tim4698

Member
Jun 16, 2019
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Kansas City, MO
Digital Tuning Pros,
Finally charged the AC up on my 93 GT and working on MS3 settings to kick on my electric fans when the AC is on. My MS3 Gold Box did not come wired to pin 10 on the factory EEC plug on either of the MS3 black or gray plugs. I'm working on adding the wire, but want to make sure the black/yellow wire is only a signal wire, so I can setup AC Idle up and AC fan control. Just wanting to make sure I understand the voltage at pin 10 to prevent frying the MS3 board when connecting it to the Tableswitch pin on the MS3 gray plug. I'm guessing that this is the only input available to let the MS3 know when the AC compressor is on. I attached my MS3 gray plug info. If anyone could help I would appreciate it. -Tim
 

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a91what

SendMeUrDataLog
Mod Dude
Apr 6, 2011
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Pin 10 is a 12v trigger input. You will need to use the 12v digital in or build a simple transistor switch with a 1k resistor and a 2n2222 bjt ...

The best way to do this is to wire the input to the ecu then use a separate output in the ac settings to trigger the wot relay, move the pin from 87a to 87 and your setup
 

tim4698

Member
Jun 16, 2019
13
1
13
42
Kansas City, MO
Nitrous in on my MS3 is a 12v + input. Just confirmed that pin 10 supplies +12v when compressor kicks on. AC has all factory wiring remaining. Can I trigger the fans using the Nitrous in for the ac idle up?