86 g-body

iTrader: (3)

Does any part of the 2 wireharnesses need to be kept or can they be unpluged from firewall???

themachasy

iTrader: (5)

If my s10 is any indication (sorry not a g-body person), I would need part of the harness through the firewall for the turn signals, headlights, and such.

86 g-body

iTrader: (3)

Come to think of it my wireharness has 3 parts one on pass side for a/c and ecm and on driver side it has 2 one for engine and the other for lights..so all I need to keep is the one for my lights right????

2Aspire

iTrader: (4)

Ditch the ECM wiring.. Keep the AC.. Leave the other on driver side..
(Temp sender, Oil pressure, Starter, ACC & BATT power, Wiper motor) and as you mentioned lights..

Matt

86 g-body

iTrader: (3)

If I'm not useing factory gauges do I still need the factory temp and oil??

HILROD

No you wouldn't

Pocket

iTrader: (22)

Find a pinout for the body connectors and use this process to disassemble the factory harness to just the wires you need. This is for a 3rd gen so just gather the general process, not the step by step procedure

http://www.thirdgen.org/techboard/lt...p-3rd-gen.html

Most 80's GM cars had a two part C100 like the 3rd gen thread up there. Half for the front lights which is untouched and the other half controlling the engine with basic power and gauge functions spread throughout. Separating the essentials from the EFI bits requires a specific pinout per year of the car

86 g-body

iTrader: (3)

So the lights,starter,wiper and a/c wires stay ?? Every thing else (batt,temp,volt etc...is aftermarket....

nj85z28

iTrader: (6)

malibu racing has alot of the diagrams you need in order to eliminate what you dont want.

2Aspire

iTrader: (4)

I have an 86 Monte Carlo SS so Im assuming that your car would be somewhat similiar.. But anyway..

I chose to keep the stock gauges... so as Hilrod mentioned if you intend to ditch the stock ones you can forget the stock provisions for temp, oil etc..

The Battery and ACC lines will remain to power Lights, interior Dome lights, Power windows, locks,(if so equiped as mine is) Cigarette lighter, Car stereo.. Also starter solinoid power runs in same loom..

86 g-body

iTrader: (3)

I would like to keep my Stock gauges how did u hook yours up.u only need the temp,batt and oil press right?? And I don't know what is what on the fact harness..

2Aspire

iTrader: (4)

Best thing to do to know for sure is to get a schematic..

Otherwise its a process of elimination and if you dont have the wiring already hooked to the original engine that may be a little more difficult..

I had mine in tact before I started to yank so it wasnt that difficult to figure out.. I got a stock temp sensor turned down on a lathe and re-threaded graciously by LS1MCSS... If you send him one he will probably do it for nothing as long as you pay for the stock sensor and the ride..

For the oil pressure.. Again I knew where the original sensor and wire was so I just used a NPT to metric adaptor for the stock sensor to the rear of intake on my LS2 and plugged it in..


It does definitly help to get a schematic of your car..I found one on the net that worked for my car (85 monte SS schematic). It was nice to have for other obvious reasons as well as for the swap...

It may not help you much in terms of color codes as I really dont know what the variances were from product line to product line for G-bodys..but will give you an idea of how an 85 G-body was wired and how useful it can be..

http://www.badss.net/other/monte_85_wiring.pdf

Cheers...

LS1MCSS

iTrader: (18)

One of the wires, from the firewall is ignition power. You need that to power the pcm. There is also the starter wire coming from there, so be very careful what you delete.