Box looks good. 4.5 ohms is way to much resistance, should be about 0 to 0.2 at the most. We need good ground. You have a probe to ground the black wires?

Actually, wait. Are they both solid black? Or one of them is black and white? If it's black and whitee it's a different wire

Also before I ask you to to give power to that green and orange wire on the black box( that you verified is at 0v when the a/c is requested). I need you to verify that that wire has no excessive resistance between one of the 2 pins on the plug going to the dual pressure switch. We don't know which pin on that plug, because it's been changed by OHM racing, but one of the 2 pins on that plug while being disconnected, should have good continuity with no resistance to that Green and orange on the black box) if not, we have an open there.

Both appear to be solid black

Vladimir said:

Also before I ask you to to give power to that green and orange wire on the black box( that you verified is at 0v when the a/c is requested). I need you to verify that that wire has no excessive resistance between one of the 2 pins on the plug going to the dual pressure switch. We don't know which pin on that plug, because it's been changed by OHM racing, but one of the 2 pins on that plug while being disconnected, should have good continuity with no resistance to that Green and orange on the black box) if not, we have an open there.

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If i remember we did that test earlier and none of the pins had continuity. I tested both pins on the dual pressure switch connector and all the pins on both black box connectors and got nothing

cswindel said:

If i remember we did that test earlier and none of the pins had continuity. I tested both pins on the dual pressure switch connector and all the pins on both black box connectors and got nothing

Click to expand...

Ok. That means we have a missing part of the circuit, ohm actually had to have made that connection happen since the plug on the dual pressure switch is changed by then...but... That still doesn't resolve why we have no power coming out on that G-O wire out of the black box.

We have to dig further, around the black box first. Because we know you are getting 12v from your a/c selector switches, and we have verified that your fin thermo sensor is working and has good resistance value and continuity to the black black box. What I don't like is that there is 4.5 ohms of resistance on the ground wire/wires connector, this indicates possible corrosion.

Can you provide a quality ground to those solid black, via power probe or just spice in and wire directly to good chassis ground ?

There is also one more switch that we have to verify. It is located on your a/c compressor. It's a temperature switch that should also be going through your black box diagrams yell different colors from what your plug looks like. But it should yellow green pin to yellow black or yellow green to yellow red. It's hard for me to verify and it's a big pain in the arse to crawl up under the car to check for continuity to verify which wires.

Vladimir said:

Ok. That means we have a missing part of the circuit, ohm actually had to have made that connection happen since the plug on the dual pressure switch is changed by then...but... That still doesn't resolve why we have no power coming out on that G-O wire out of the black box.

We have to dig further, around the black box first. Because we know you are getting 12v from your a/c selector switches, and we have verified that your fin thermo sensor is working and has good resistance value and continuity to the black black box. What I don't like is that there is 4.5 ohms of resistance on the ground wire/wires connector, this indicates possible corrosion.

Can you provide a quality ground to those solid black, via power probe or just spice in and wire directly to good chassis ground ?

There is also one more switch that we have to verify. It is located on your a/c compressor. It's a temperature switch that should also be going through your black box diagrams yell different colors from what your plug looks like. But it should yellow green pin to yellow black or yellow green to yellow red. It's hard for me to verify and it's a big pain in the arse to crawl up under the car to check for continuity to verify which wires.

Click to expand...

Yeah i mean if they are both grounds I can definitely do that. Ill just splice them together to a single common chassis ground wire

That temp switch isnt part of the 3 pin connector is it?

If they are both solid black, diagrams say solid black is ground. Also take a picture of that connector on the female side where it connects to the black box

How's that

Do you have a power probe?

Vladimir said:

Do you have a power probe?

Click to expand...

Unfortunately not

Make a temporary spice to ground the black to good chassis ground

Temporary? How do I go about that? Just back probe the connector and ground it

I would splice into the wires or you can cut them and put crimp connector to lead to good ground. Just leave enough room to turn them back to factor, if necessary, Do it further from the plug since you have no power probe, we need good ground, we cant have 4.5 ohms

Just gave this a go

You made a splice and used an alligator, booster wire to ground?

Connect everything back with the ground fixed. Turn on all the controls for a/c and see if we are getting 12v at the G-O wire now.

Haha yeah I just stuck a paper clip in the back and alligator clipped it to ground.

You want it plugged into the black box and then have the g-o wire back probbed?

Yes. Plug back, With the blower ON, a/c set to cold and a/c switch pressed and indicator light on, start the car as well.. Does 12 v gets to that G-O wire? Or does it just stay on the blue wire?

I gave power to the car and the ground resistance went up a lot. One wire was at 3.3 ohm and the other was at 2.6 ohm. This was just turning the battery on and having it unplugged

Something is not right. All diagram show solid black as a constant chassis ground. There should not be any floating resistance or anything of that nature. Just a constant 12 v groundaccording to all diagram

I'm sorry I typed 12v ground I ment ground. And 12v at the L-B wire. Then power goes through the thermo and into the G-O. G-O gives power to pressure switch

Yeah i have no clue why the resistance jumped. I re-probed it and got 0.3-0.4 ohm at each ground with no power. As soone as I turn the kill switch on it jumps and thats with keeping the additional ground point to chassis

Something is not right. Have I ever asked you to give 12v to either one of the 2 pins on the dual pressure switch connector while it's still connected, with all your a/c setting set to a/c with the blower oN, and car running? If not can you just do that really quick.

Does it matter which pin? Also do I need to hook the black box back up to the connectors

Yes hook everything back. Like it was. Do it later. Either one of the pins would work as long as the dual pressure switch plug is connected and you got pressure in the system.

I find it very difficult going over all of this testing stuff, it's so easy to do if I'm next to the car but with the car in Cali and all the wiring replaced, plus no 2 g to reference it's so difficult to explain, all the testing so far shouldn't have taken more than 20-30 minutes, but it take time to explain and you have to be at least somewhat knowledged in reading schematic and seeing how everything works. I'm just trying to simplify everything as much as possible.

When you give direct power to the switch tomorrow or whatever we can continue: just lmk .

We verified that your mechanical side of the a/c works but we cant verify normal pressures. Acted like there might be a clog. We have to solve electric side first

So far we have confirmed that your OHM harness actually comes with 2 pins going to the ECU ( doesn't mean it's complete

We verified that your dual press switch works as it should.

We verified that your clutch is kicking when jumping power from relay

We verified that your a/c control head sends power to the black box auto a/c controller.

We verified that the fin thermo is still connected to the black box and it has good resistance (within spec) based on ambient temperature.

You also told me that the pins on the dual press switch don't make circuit with the G-O wire on the black box. We have to look for why that circuit is open

We still haven't verified your compressor temp switch (mounted on the compressor going to black box) operation.

We cant verify yet why there is no 12v going to G-O wire, coming out of black box to dual press and condenser fan.

There is still some testing. Also it's a little harder to do them without test light and power probe.

Worst case scenario, like I told you previously, I can draw a simple sketch for you on how to make this system work through the dual press switch without the black box and ecu. You can use the 2 relays that you have for condenser fan and a/c switch, and just spend a little money on wiring. That would not require you to be heavily knowledgeable in electrical diagnostic and wiring , and will be a 1000 times easier to explain.

But that's the last resort. We can continue what we started for now

Well all I can say is OHM strikes again. This wire was the last piece of the puzzle to fix

And as many connectors as I tested and as much of my interior i pulled apart I could not get continuity anywhere. The only place I didnt check was the quick disconnect location under the fender but im not pulling body panels off to fix more of their mistakes. In total I have about a month and a half worth of my time and other people's time spent chasing down issues with their harnesses and I have fixed 2 major issues with pins being in the wrong locations

My best guess is that this wire for the dual pressure switch was wired incorrectly somewhere in the harness but im done chasing it

OHM is going to send me a re-wire solution and ill post on here if it fixes it or not

Hell yeah! We can finally make it all green ))))). We kinda knew it was something OHM did as soon as we found out that the B-76 connector to dual press switch was one pin off...... Good the owned up to it. Glad you got a/c now