Converting a 89 2.3 harness to work with a LA3. PIN 27

[ianb]

Im attempting to check for wiring breaks with my junkyard harness out of the car. I have 88 TC LA3 ecu and motor for a swap going in a 89 notchback fox body with no engine harness in it.

When switching over to use a VAM going by the instructions found on our site im cutting up the 3 wired EGR connector and not using it going forward (im assuming). Im following a 2.3 NA wiring diagram for my year and its showing the following pin outs, somebody correct me if im wrong.

Connect the Orange/White from EGR (PIN 26) to the Orange/White from VAM.
Connect the Brown/Light Green wire (PIN 27) from EGR to the White/Black from VAM.
Connect the Black/White wire (PIN 46) from EGR to the Black/White from VAM.


My issue is with PIN 27 aka Brown/light green not ohming out at the ecu connector at pin 27 or anywhere for that matter. If I follow that wire it goes into another 2 wire connector on the harness which I cant figure out what it is.



And from the other end of that mystery connector that wire leads to another connector which I cant figure out what it is.



White/Black Stripe, Variable Voltage--------------->>> Brown/Light Green Stripe

So is "Variable Voltage" the same thing as a "VANE Air Flow" which is PIN 27 on a 87/88 turbo coupe? If so does it make sense to have the wire for this jump around to 2 different connectors? I know this harness came from a fox body it had a distributor it was definitely a 2.3 lol.

If this sounds right then ill leave it as is but its not ringing out but its not in the car either

[Stinger]

Variable voltage means it can read 0-5v depending on conditions (like a TPS does) and VANE Air Flow varies voltage as it opens farther so yes, they are the same thing.

Since hundreds of people have used that swap guide without issue, my suggestion would be wire it as it states and revisit that wire if it doesn't work correctly.

[ianb]

Stinger im going to be working installing the 89 2.3 NA harness this week and next week. Once I establish all the right connectors to the 2.3T sensors I should be left a bunch of useless connectors like A/C, Knock Sensor, ect. Is there any reason to keep them or can I cut them off/tape up the ends to help up to clean up the bay?

[Stinger]

You can get rid of them IF you connect all of the VREF wires together (normally red/green). I suggest verifying functionality before removing all of them. That way if it works before you remove them but not after, you have narrowed down where the problem is.

[ianb]

Feb 17, 2020 14:30:31 GMT -5 Stinger said:

You can get rid of them IF you connect all of the VREF wires together (normally red/green). I suggest verifying functionality before removing all of them. That way if it works before you remove them but not after, you have narrowed down where the problem is.

Okay thanks I’ll save that project for a later date when it’s all running.

[ianb]

Quick little update regarding my original issue. I am an idiot and didn’t realize the mystery connector connected to another portion of the main harness. Guess you can consider them sub harnesses. Either way once I connected them I was able to ring out pin 27 to the Vam and all everything is ohming out correctly.

It’s pretty embarrassing to be honest with you and a right in my face fix that my buddy pointed out, but maybe it’ll save somebody a headache later.

I’m getting closer to attempting to start this car I’m pretty excited.

[Stinger]

Yeah, that's why I always caution removing any connectors unless 1) it's already up and running and 2) you pull all the loom off the harness so you can trace each wire and make sure you're not killing a circuit if you remove it. The way the harnesses are made, you're certain to make it non-functional in some way removing connectors. Glad you figured it out.