Hondata

Ok so I found a "how to" when I used the search function. But let me double check this.

So I have a 93 civic SI with an s300 p28.

My car came without A/C. So I want to hook up the original AC button to work when I want to datalog.

I've read that you have to Cut the B5 wire, and wire it directly to the Blue/Red wire from the heater control unit. And also to Ground the Green wire (tap it into the ground wire from the heater control unit).

Can anyone confirm how to do this? I'd like to use this. It would be a great feature :)

Thanks,
-Jose

This link is where I got the information from:

http://www.hondata.com/forum/viewtopic. ... fcf43ed77f

I figured it out (I'm stupid)

For future refference:

Cut B5 (blue/red) on the ECU and connect it to (blue/red) on the green plug on your heater control panel.
Then cut the (green) wire on the green plug and tap it into the (black) wire on the beige plug (heater fan switch 6p)

8)

Now I can datalog by using the AC button on my heater control panel.

Yes,sorry,maybe i could have labelled that diagram a bit better,i just forget that sometimes electrical diagrams are not quite as clear to others as they are to myself....

What u have to achieve is to bypass the A/C thermostat & pressure switch,which are tapped in line on the blue/red wire, on its journey from the A/C switch to the ECU.

If u have no gas in your A/C system then the A/C pressure switch will be open & the EcU will not receive signal from A/C switch.

If u have not powered the thermostat than it too will remain open & even if u power it the temperature variations will see it cycling on & off,no good for your datalogs lol.

If u have removed all your A/C wiring which is a seperate optional loom(which usually happens when people rip out the entire A/C system),then the blue/red wire will no longer be continuous to the ECU from A/C switch.

In the above 3 cases u can see why its necessary to locate the blue/red wire at the ECU & A/C switch & join it directly together,thus bypassing all the above hazards.

For the green wire(ground) u would have to have your fan switched to one of the four on(speed) selections for the A/C switch to work,which is not ideal,so thats why u have to give the A/C switch a direct connection to ground also via the green wire.

Yup lol!

After looking at the shop manual and your instructions a few times I finally figured it out lol

It really isnt that hard. I ran into trouble because I didnt have the green wire ground correctly to the black ground wire.