Engine harness plug identification

[strutaeng]

I already have the ac clutch plugged in. It’s on the same branch of the harness as the ac clutch.

The ground I am looking is the smaller of the two coming right off the negative battery terminal. I think it goes to the frame somewhere.

It goes to the engine block, behind the power steering pump.

IDK what that plug near the AC compressor goes. I vaguely remember some air compressors actually have 2 connectors? Like the later GMT800s? What year is your truck?

 

[strutaeng]

I have the same problem on a 1998 Tahoe and if you drop the wire plug it's down around the throttle body in that area between the alternator and the cover for the throttle body

You should start a new thread. Your truck and OPs are completely different on the wiring harness... different generation of vehicles.

 

[jeffg]

top of frame in the front towards bumper

I think that handles the ground. I will update if I find the home for the smaller plug.

 

[Doubeleive]

I think that handles the ground. I will update if I find the home for the smaller plug.

passenger side area doesn't have many choices, either hvac or maf, cam position sensor, starter, 02 sensor, engine block heater, coolant level sensor.
can't think of anything else at the moment
*looking at it again it does look like 02 sensor which is why it is low like that

 

[jeffg]

Turns out the mystery plug on the passanger side plugged into a sensor on the AC line just in front of the compressor.

Engine is ready for fluids and first start up.

2004 Tahoe
LQ9 with BTR "TruckNorris" cam, springs, rockers
Ported 317 heads

Lowered on Eibach ProKit+DJM+Spohn

 

[strutaeng]

Turns out the mystery plug on the passanger side plugged into a sensor on the AC line just in front of the compressor.

Engine is ready for fluids and first start up.

2004 Tahoe
LQ9 with BTR "TruckNorris" cam, springs, rockers
Ported 317 heads

Lowered on Eibach ProKit+DJM+Spohn

Looking good. Did you get a tune for the aftermarket cam?

 

[jeffg]

I am going to start it on the factory flex fuel ecu and tune, but it will be headed to the dyno for proper tuning after break in.

 

[justirv]

I'll go out and take a

Turns out the mystery plug on the passanger side plugged into a sensor on the AC line just in front of the compressor.

Engine is ready for fluids and first start up.

2004 Tahoe
LQ9 with BTR "TruckNorris" cam, springs, rockers
Ported 317 heads

Lowered on Eibach ProKit+DJM+Spohn

Great to hear you found where the connector went. All I found was the A/C connector and what appears to be the wheel speed sensor on that (passenger) side.

As far as the small ground at the battery, mine goes down and under the radiator support. I did not take the grill apart to see where it landed, the second pic shows it crossing horizontally under the support towards the front.

 

[jeffg]

Thank you for checking. I haven’t put the rad support back in yet. Hopefully it will be obvious once I do.

 

[jeffg]

Finally got all of the wiring sorted (stupid dummy fuse in the fuse block), and the LQ9 is running. Holy crap. I don't know if the 5.3 was just that tired, but the 6.0 is night and day different. The tuner has serious concerns about the 4L60e surviving, so starting work on getting an 4L80e rebuilt.