I do not have the factory engine wiring harness or ecu.
Can I still setup the factory ac to run off the logicon?

 

the compressor relay is the only thing you need to activate and it is in the relay cluster next to the hood latch. how you activate it is up to you.

 

Can it be activated via logicon without ecu or engine harness?

 

Wait for one of the wiring experts to arrive, but can't see why it can't be wired to the A/C button, but
you'll also need a way to bump up the idle when the compressor is running. You also need to have an
evap temp sensor to control the compressor when the evap is reaching the freezing point.
Many years ago installed air in a few cars and on one I used an electric anti-stall dashpot to be activated
when the compressor was on.

Back in @ 1983 I put air in our '89 RX7 Limited and ran great for the first 15 miles, then white mist started
coming out of the vents. Got home, installed the sensor probe into the evap, and then was fine.

 

IIRC the logicon a/c button runs through the ECU, and the ECU will rely on the pressure switch, so you'd have wiring to figure out

 

Hmm i thought the compressor was inturrupted with a thermoswitch... learn something new everyday

 

I could be wrong, but i swear i remember reading that somewhere on the forums

 

You can, there are two wires on the body side of the ecu plug that need to be jumpered to bypass what used to be the ECU. I don't know which off the top of my head but there should be some information in the standalone ems section of this forum.

 

Rest of the system aside, such as type of charge, pressure switch, triggering the fan if you have an electric fan, fully operational logicon, etc and so forth

Wiring wise Just tie the BLUE/ORANGE and BLUE/WHITE wires together on the plug where the factory ecu was. I just used a small piece of wire and stuck it in there

My ac still doesnt quite work i have a leak somewhere but it did work pretty good for a little bit .

The amount of time and money i have into this crap makes me sick lol

 

Will this work even tho I don't have the factory wiring harness? The problem is, I can't find the wire that connects to the compressor wire.

 

If you have the factory body harness and not the engine harness, all you would have to to is jumper the two wires as Rob mentioned to retain factory operation.

The wire that connects to the compressor clutch comes from the body harness.

 

So, I jumper the two wires, then where do I connect the compressor wire? It's not connected to anything currently.

 

What model Haltech? Some of them have built in A/C control. You feed the AC activation signal to an input, then the ECU provides an output to switch the compressor on/off, which would then generally be connected through your trinary/binary switch.

Advantage being that the ECU can idle up the engine via the BAC and activate the cooling fan. Also shut the compressor off at WOT.

So basically directly taking the place of the stock ECU.

 

Sprint RE-some quick research tells me that it unfortunately does not directly support ac. So, Im thinking I wont be able to wire it thru the hatech ecu. Need to figure out some way to wire it directly to the logicon.

 

i suggest you look in the wiring diagram, i think the ecu grounds the logicons output, they did this just so the ecu knows when the ac is on. it used the connector on the body side, so the wires rob mentioned will still be there

 

That's unfortunate. If you look at the diagram in the Haynes/FSM as others have said, the logicon just tells the stock ECU it wants A/C, and the stock ECU then activates the compressor. You can rewire the logicon to switch a relay instead which gives you the option to invert the signal if necessary.