Engine Comp. wiring *************HELP PLEASE

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.

bobby v

I'm Awesome
Joined
Jan 6, 2019
Messages
345
Reaction score
381
Location
lake havasu city AZ
These are just unknown wires on the pass side of my motor that I'm trying to find info on. You can see the one set is wrapped in what looks to be the factory harness laying alongside the manifold on top of the valve cover, The oblong one has power when the key is on, the smaller one doesn’t??

I should mention everything on the truck works. Did the OEM air cleaner have some type of a monitoring system??

The other set comes out of the firewall and the length extends to clear in front of the trucks grille, I thought maybe it was for the Aux A/C fan but that’s connected already. Neither plug has power to it with key on. I know that the factory sends cars with a stock wiring harness that has provisions for other addon items and they just leave them blank so I'm wondering if this is that.

Anyways if you can decipher any info it would be appreciated

Bobby

PS I always for get1990 SS454 auto, a/c and all power
 

bobby v

I'm Awesome
Joined
Jan 6, 2019
Messages
345
Reaction score
381
Location
lake havasu city AZ
These are just unknown wires on the pass side of my motor that I'm trying to find info on. You can see the one set is wrapped in what looks to be the factory harness laying alongside the manifold on top of the valve cover, The oblong one has power when the key is on, the smaller one doesn’t??

I should mention everything on the truck works. Did the OEM air cleaner have some type of a monitoring system??

The other set comes out of the firewall and the length extends to clear in front of the trucks grille, I thought maybe it was for the Aux A/C fan but that’s connected already. Neither plug has power to it with key on. I know that the factory sends cars with a stock wiring harness that has provisions for other addon items and they just leave them blank so I'm wondering if this is that.

Anyways if you can decipher any info it would be appreciated

Bobby

PS I always for get1990 SS454 auto, a/c and all power

You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach
 

arrg

I'm Awesome
Joined
Apr 29, 2015
Messages
402
Reaction score
314
Location
North Las Vegas, NV
My guess is the one with the orange band goes to your EGR solenoid; the one with the green band goes to your AIR pump diverter valve. Since it's a 454SS, I'd guess the long ones have something to do with the fog lights, but that's just a guess based off the length, the picture is too blurry. Looks like someone has been into your harness as they don't come wrapped in tape from the factory.
 

PlayingWithTBI

2022 Truck of the Year
Supporting Member
Joined
Jan 3, 2019
Messages
9,658
Reaction score
14,981
Location
Tonopah, AZ
My guess is the one with the orange band goes to your EGR solenoid; the one with the green band goes to your AIR pump diverter valve
IIRC the ESC (for knock sensor) has a 4 pin plug with 3 wires (at least for the SBC), not sure if your BBC has one.
 

bobby v

I'm Awesome
Joined
Jan 6, 2019
Messages
345
Reaction score
381
Location
lake havasu city AZ
Arrg****
Sorry about the photos, they suck and thanks, the long lead seems a mystery, my fog lites are wired and work as they should so that's not it. It comes out of the plastic cover on the firewall pass side so Ill remove that and see where they originate, maybe that will help.. :(
Thanks Pete, man I wish we weren so far apart, but then you'd probably have to chase me off with a baseball bat, so much too learn and you seem to know it ;)
My weekend neighbor has a 90 with a 350 so Ill take a peak at his, maybe that will help.
Bobby
PS Better photos, the last three are of the long loom and where it comes out from under the black plastic housing on the firewall and the plugs themselves.
Im assuming you (Pete is correct) on the ones laying on the valve cover as that seems to be a factory loom although I don't know what your abbreviations stand for but Ill look them up for my self

You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach
 
Last edited:

bobby v

I'm Awesome
Joined
Jan 6, 2019
Messages
345
Reaction score
381
Location
lake havasu city AZ
OK Pete, is this what the terms mean
IIRC = If im remembering correctly ????
ESC = Electronic stability control ??? I find that GM didn't introduce this ability until about 1996 and only on select Cadillacs ???
Remember Im old and don't get out much LOL
Bobby
 

bobby v

I'm Awesome
Joined
Jan 6, 2019
Messages
345
Reaction score
381
Location
lake havasu city AZ
The long single plug is most likely the T400 kickdown lead

Since the truck now has a 700R4 I am to assume it doesn't need that then ?? I just tried turning on the lights & fogs to see if it had power but nope, so I tie wrapped it up as nicely as I could and tucked it away until its figured out, I just don't like not knowing what its for.
Thanks
 

arrg

I'm Awesome
Joined
Apr 29, 2015
Messages
402
Reaction score
314
Location
North Las Vegas, NV
The one with the orange band, with the pink/black, gray, and black/white wire goes to the electronic vacuum regulator valve (E.V.R.V.) aka EGR solenoid, and the one with the green band with the pink/black and brown wire goes to AIR injection diverter valve. If that white plug has tan/black and light blue wires, its for the T400 kickdown.
You must be registered for see images attach
 
Last edited:
Top