I am planning on taking the ECU and a lot of the wiring out of my 1985 Z28 Camaro, because I am soon putting a carbed 383 stroker in it. What I need to know is which wires I need to leave and which wires need to go. I don't know where the alternator wire is routed to from the alternator & battery? Also, by taking out most of the wiring harness, will the gauge cluster and interor lights still work? Please give me all the info. I will need about the wiring when installing a carbed, NON-ECU engine.

I know basic wiring stuff, but I'm no expert by any means, so you may have to explain to me like I'm a 3rd grader.

 

There's two places where the wiring goes into the passenger compartment.

The bundle going throught the passenger fender is all ECM related. Everything connected to that bundle you can remove. The other is the bulkhead connector by the brake master cylinder. Everything connected to that you'll probably want to keep. Some of the wiring might overlap (run inside the same looming and tangled with) the other harness, but are essentially two separate harnesses.
They may not in your 85. I forget the exact year they started overlapping the wiring (I think 88), but the earlier ones are clearly two seperate harnesses.

The wiring you'll have to install is of course dependant on the accessories you'll have, such as AC. You'll have to run the appropriate wiring for the distributor/ignition, alternator, etc.

Gauges don't run off of anything related to the ECM. (Or does the tach lead?)
Fuel level comes from the back of the car and is run inside the vehicle.
Speedo is cable-driven obviously. Voltage you'll run from your alternator. Oil pressure you'll either run from your new sender if you install one, or you can tap into the factory wiring (ask when it comes time). And water temp senDER nowhere near the water temp senSOR and is on the other side of the block from the water temp sWITCH for the electric fan(s).

 

Thank you a ton for that bit of info. It is just what I needed. Can you tell me how the alternator and distributor/ignition should be wired? Or send me a decent picture. thankssss

 

WARNING!!! DON"T CUT ALL WIRES!!!!

There is a green and blue wire that runs from your transmission, through the passenger wall, and to your reverse lights!!!

I'm in the same boat as you (383 Stroker from my 86 Irock, Except I'm putting a supercharger on mine :-)) So far thats the only one i noticed that runs on that side. I am re-routing mine to run to the drivers side firewall, so i don't have ANY wires running on that passenger.

I've also been able to remove ALL the relays on the upper drivers side corner of the firewall... also removed a relay right next to the battery. Gauges should be fine. But the Tach runs from your distributer to the drivers side firewall (brown wire), wire also runs from right under your distributor to same place in fire wall for Oil pressure (unknown color)

Umm.. thats all i can think of on the top of my head...

Let me know if you allready cut those two wires.

 

Awesome man. Thanks for that info, that will save me a lot of hassel. I am planning on taking it one step at a time so I don't fudge anything up too badly.

I wonder why the transmission reverse lights come up from the transmission and then go through the firewall into the engine compartment and back to the lights? Maybe that's to get juice and ground first?

 

The reverse lights are switched from the shifter. That's all inside the car. Um.. if I remember, the wires from the transmission run up into the engine compartment then into that bundle that goes into the passenger side fender to the ECM. Those control the torque converter lockup, and let the ECM know if you're in park/neutral and/or first gear depending on application.

But definitely like serpentineocean said, don't cut wires if you don't have to. If it was me doing what you're doing, I'd pull disconnect and pull the entire harness out, then weed out the circuits I didn't want. It's extrememly painful, but you get a much cleaner result. I've already done it twice, and am about to do it again on my convertible.

Sorry... camera phone.. not the greatest pic..

 

Hmm... Yea, Mine's a manual, so it may be different.

 

I definitely want the install to be clean and I would love to get rid of all the extra wiring. I think you guys are giving me the right idea. That picture you showed was sure worth a thousand words. My other question is... when I remove the ECU, I know the torque converter will not longer lock up. I believe there are kits to buy that will lock it up manually, but how would I be able to have it lock up automatically when the TC needs to be locked. If anyone has any info. on how those work please fill me in. Thank ya.

 

There's a kit available that runs off of vacuum to determine when to lock up the torque converter.

 

Okay, great. Who makes the best one?

 

How about TCI?

JEGS High Performance - TCI 200R4 / 700R4 Torque Converter Lock-Up Kit

 

thank ya much

 

imbringing this oen up because you said it runs off vacuum ?

why would it do that ?

doesnt make sense to me

if it uses vacuum to sense when to lock it up then that means its going to lock it up in every gear when it get the certain vacuum reading

or maybe not every gear, but at least a couple times before it gets into 4th gear

want to elaborate ?

thanks

 

I'm curious too. I like to learn new stuff.

 

oh wait after more reading and comprehending i think i see what the vacuum thing is all about

it seems to be optional and to help keep it from locking up in other gears other than in 4th

or something like that

am i getting closer ?

lol


also i was just reading here on this page:
700R4 Info Page 2


and it sounds like that its not that coasting without lockup being engaged is wats bad, but that coasting without it locked up is whats the worst, on the sprag, due to extended overrunning

hmmm

someone want to add to this?


thanks

 

If you have or chose to keep your cruise control, please note the following (also note the blue and green wires for reverse lights):

https://www.thirdgen.org/forums/engi...-function.html

JamesC