CCC Era Wiring Question For Those w/Experience (Been There, Done That)

[scoti]

The '81 El Camino I picked-up over a year ago is getting some love to move it on down the road.

This thing started out w/a CCC carb'd 6cyl/th350c combo but a 305 was CRUDELY swapped in @ some point in its life. It had a Holley 4-barrel w/adapter combo on a GM aluminum QJ intake (LG 305 intake), no cat-convertor, & all wiring to the o2 in the exhaust was not plugged in. It was a rats nest as far as underhood wiring (most of it in poor condition cut/ripped apart). We yanked the 305 & found several main & rod bearings bad so I'm swapping in a known 60k mile '78 non-CCC running drivetrain.

I started sorting through the rats nest of wires & have the main harness routings for actual functionality:
* Starting/power
* Charging/alt
* A/C
* Heater/relays

The bulky CCC related engine compartment wiring portion of the harness is surprisingly isolated from the rest. Is it as simple as removing the computer from under the top kick panel & just yanking the wire through the firewall? Or.... Are these wires routed within the cabin/under-dash harness which means I'll have to dig deeper to fully remove the CCC related wiring?

Again, we're moving this one on w/o getting stupid involved into anything if possible. If the wiring is tied to the dash/cabin stuff I'll have to just figure a way to loop & secure it underhood. But if it's simply just the need to yank it (& not having to mess w/the dash/cabin wiring) I'd rather do that for a cleaner set-up. Those that have been @ this crossroad..... let me know what you encountered.

 

[pagrunt]

The bulky CCC related engine compartment wiring portion of the harness is surprisingly isolated from the rest. Is it as simple as removing the computer from under the top kick panel & just yanking the wire through the firewall? Or.... Are these wires routed within the cabin/under-dash harness which means I'll have to dig deeper to fully remove the CCC related wiring?

Again, we're moving this one on w/o getting stupid involved into anything if possible. If the wiring is tied to the dash/cabin stuff I'll have to just figure a way to loop & secure it underhood. But if it's simply just the need to yank it (& not having to mess w/the dash/cabin wiring) I'd rather do that for a cleaner set-up. Those that have been @ this crossroad..... let me know what you encountered.

All that underhood wiring is fed thru a hole in the firewall just under the bottom outboard corner of the heat-A/C box. There will be a metal wire gaurd/cover on the engine side, held on with two small bolts. There is a 15 cavity connector with 13 wires that connects to the dash harness. That dash harness part is wrapped into the main dash harness so it would kinda require that section to be left in it unless you pull the dash & unwrap it out of it.

 

[scoti]

I knew about the hole in the corner under the HVAC box but what you described is what I suspected (a 'leg' that tied into the dash wiring for gauges/power etc).

Guess I have to make a decision. I might just stuff it into the cavity of the pass side fender after taping off any exposed ends.

Appreciate your feedback.

 

[78Delta88]

Before yanking out... Does your 81 have cruise control?

 

[pagrunt]

Before yanking out... Does your 81 have cruise control?

That won't be a worry, '81 didn't tie the cruise into the computer. It was the same as the earlier version but included the Resume mode which was a new feature for cruise control in '81.

 

[Clone TIE Pilot]

CCC harness usually have just 3 connectors inside the cabin. Two that go into the ECM itself and one that connects to the plug for the under dash harness. 81 is an oddball year for CCC so I am not sure if a later V8 CCC harness will plug into the under dash harness. When I swapped swapped my 86 Buick V6 out for a 86 Chevy 305, the 305 CCC harness was pretty much just plug and play into my Regal. The VSS, SES light and module, and ALDL are part of the under dash harness and the only items that should plug into the CCC harness. Sometimes with V6s they put the BARO sensor under the dash instead of in the engine bay like with most V8s.

 

[pagrunt]

CCC harness usually have just 3 connectors inside the cabin. Two that go into the ECM itself and one that connects to the plug for the under dash harness. 81 is an oddball year for CCC so I am not sure if a later V8 CCC harness will plug into the under dash harness. When I swapped swapped my 86 Buick V6 out for a 86 Chevy 305, the 305 harness was pretty much just plug and play into my Regal. The VSS and ALDL are part of the under dash harness and the only items that should plug into the CCC harness. Sometimes with V6s they put the BARO sensor under the dash instead of the engine bay like with most V8s.

The LC3 229 didn't. Everything was under the hood on my original set up. All I had was the VSS, ALDL & the wire leads for the check engine light going into the cluster connector.

 

[78Delta88]

Good on the cruise control. There are several threads on cruise and a line that needed grounded when disconnecting the ECM. Never had to deal with that before.

 

[scoti]

Before yanking out... Does your 81 have cruise control?

To be honest.... IDK. I'll have to check after work. If it does, it def was not functional based on the condition of everything else.

 

[scoti]

I decided to tape off exposed wires/clips & tucked that wiring into the fender. Cleaned up the excess under hood w/o it just laying there half-arse. It's now alive & running well.