Engine harness plug identification

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

strutaeng

Full Access Member
Joined
Aug 10, 2023
Posts
1,124
Reaction score
2,313
Location
Dallas, Texas
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

Full Access Member
Joined
Aug 10, 2023
Posts
1,124
Reaction score
2,313
Location
Dallas, Texas
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.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
25,995
Reaction score
38,779
Location
Stockton, Ca.
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
SENS.jpg
 
OP
OP
J

jeffg

Member
Joined
May 9, 2022
Posts
39
Reaction score
58
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
 

Attachments

  • IMG_5270.jpg
    IMG_5270.jpg
    273.8 KB · Views: 2

strutaeng

Full Access Member
Joined
Aug 10, 2023
Posts
1,124
Reaction score
2,313
Location
Dallas, Texas
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?
 

justirv

Member
Joined
Dec 28, 2011
Posts
77
Reaction score
83
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.
 

Attachments

  • 20241103_133438.jpg
    20241103_133438.jpg
    137.2 KB · Views: 3
  • 20241103_133417.jpg
    20241103_133417.jpg
    197.8 KB · Views: 1
OP
OP
J

jeffg

Member
Joined
May 9, 2022
Posts
39
Reaction score
58
Thank you for checking. I haven’t put the rad support back in yet. Hopefully it will be obvious once I do.
 

Forum statistics

Threads
132,030
Posts
1,861,251
Members
96,474
Latest member
Austin prather
Top