V1 SC vs TC Wiring (from Video)

[Robinjo]

I've been re-watching and re-watching the wiring video trying to get myself up to do the wiring. On the latest re-watch they mention the TC version intercooler pump but never mention the SC version. Is this covered by the harness someplace else or do we also follow the TC directions? How does the SC heat exchanger pump get wired and powered?

 

[Sluggonaut]

I've been re-watching and re-watching the wiring video trying to get myself up to do the wiring. On the latest re-watch they mention the TC version intercooler pump but never mention the SC version. Is this covered by the harness someplace else or do we also follow the TC directions? How does the SC heat exchanger pump get wired and powered?

The SC already has the heat exchanger pump wired in - it's already in the stock engine harness.

 

[Robinjo]

So, no need to do anything for it?

 

[Ross]

No need. We don't have to modify the engine harness... but you can later if you want to reuse the AC pressure sensor for a wideband O2 sensor, or an oil pressure sensor.

 

[Ghostknife]

No need. We don't have to modify the engine harness... but you can later if you want to reuse the AC pressure sensor for a wideband O2 sensor, or an oil pressure sensor.

that's not comforting, I didn't event think of this while doing my harness. I guess I have a turbo harness now lol. I will have to go back through and see what I need to fix

 

[Robinjo]

that's not comforting, I didn't event think of this while doing my harness. I guess I have a turbo harness now lol. I will have to go back through and see what I need to fix

I already cut out my A/C plugs from the harness as shown in the videos as well.....

 

[Gtstorey]

You wouldn't use the ac plug anyway. Just don't cut the wires at ECM or at least don't cut them short.

 

[Sluggonaut]

I used the wire that the video had us extend for the IC pump as an extra key-on power wire.

 

[Robinjo]

You wouldn't use the ac plug anyway. Just don't cut the wires at ECM or at least don't cut them short.

I cut them at the branch where the A/C plugs/wires mate with the heat exchanger pump. I then taped the area up well as to not have exposed wires showing so there is some length under all that.

No need. We don't have to modify the engine harness... but you can later if you want to reuse the AC pressure sensor for a wideband O2 sensor, or an oil pressure sensor.

How would one even do this? How do A/C wires get turned into a wideband connection? I'm interested in running an A/F gauge at some point.

 

[Gtstorey]

How would one even do this? How do A/C wires get turned into a wideband connection? I'm interested in running an A/F gauge at some point.

Engine wiring questions

Thanks for clarifying.

dfkitcar.com

 

[Sluggonaut]

I cut them at the branch where the A/C plugs/wires mate with the heat exchanger pump. I then taped the area up well as to not have exposed wires showing so there is some length under all that.


How would one even do this? How do A/C wires get turned into a wideband connection? I'm interested in running an A/F gauge at some point.

I was asking questions about this until I discovered the AC wire trick is for sending the signal to HPT for logging using an existing O2 sensor. I already have a wideband sensor/gauge and will be using the serial port to log with HPT at some point.

 

[Robinjo]

Ah, so you have to use HP Tuners. I'm not going down that route just yet. Maybe in the future when I feel like learning to tune, I'm not quite that much of a sadist. Doing the wiring myself is about the pain level I'm ready for.

 

[Gtstorey]

I have HP Tuners and can probably help some on the basic tuning, although I'm still pretty new and learning on the LNF.

 

[Ross]

How would one even do this? How do A/C wires get turned into a wideband connection? I'm interested in running an A/F gauge at some point.

The A/C Refrigerant Pressure sensor is just a 0-5V signal that the PCM reports on... and will programmatically turn on and off the A/C compressor clutch. Since we don't use either of these, they could be wired to a different 0-5V sensor.

The LSJ has 3 wires going to the A/C Refrigerant Pressure sensor, a 5V+ (grey wire), a negative (black wire, Low Reference) and a signal (red with a black strip wire). These wires could go to your new sensor (Oil pressure, or O2 wideband). Rauq created a great thread on Wiring Wideband O2 Sensors.

Once wired to your new sensor, you can monitor the old A/C pressure in HP Tuners OR buy one of those programmable OBD2 gauges, and find the GM PID code for the A/C pressure, and program the gauge to show it. Of course you also need to scale the gauge, as the AC pressure gauge probably will indicate different pressures that your oil pressure sensor, or your O2 wideband sensor. Properly scaled, the programmable OBD2 gauge can now show your oil pressure or O2 wideband's air/fuel ratio.

 

[Robinjo]

You might as well put up Egyptian hieroglyphics because that's all I see in that photo! I am by no means an electrical schematics guy.

I have HP Tuners and can probably help some on the basic tuning, although I'm still pretty new and learning on the LNF.

I may go this route in the future, but for now we're 'trying' to stay in a certain dollar amount. I just blew a bunch of the money for extras on a second intake manifold (with twin pass), header, phenolic spacer and the a new fuel pump (because I like to break hoses). My engine currently has the GM Stage 2 components on it but it'll go to a ZZP Stage 3 setup at which point it might be good to learn to tune. That'll be in the future as I want to get used to what I have in the current condition.

So, I can't just use an AEM OBD-2 wideband setup on the LSJ?

 

[Gtstorey]

To tune with HP Tuners, you have to get the wideband info into the scanner file. There are multiple ways of doing that. I have the newest version with the pro features so most of available ways can be used although I may have to add the $34 pro link+ cable.