with rodj.
Is 85 to 89 wiring the same?
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
I could be way off here but it looks like there are options available in 89 that were not in 85 so certainly wiring would be different, someone will certainly ask... Do you mean a specific harness or just all wiring in general?
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
85 is 'unique', pita to repin to 86-89 type -165 ecm but possible if highly motivated.
89 lost cold start sensor/timer wires and 9th injector wires.
IIRC there are also a few wire color variations between MY's
part way thru 89, wire insulation was upgraded.
89 lost cold start sensor/timer wires and 9th injector wires.
IIRC there are also a few wire color variations between MY's
part way thru 89, wire insulation was upgraded.
Last edited by redrose; Jan 12, 2011 at 09:58 PM.
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
Wouldn't call the 85 crappy. Call it a major step forward, basic, innovative but not crappy. The Burn off module was a means to an end. In most cases has worked well for a lot of years. Oh yes, the 85 ECM is very slow in output compared to say 86, but faster than anything prior. 85 ECM and MAF burn off can be upgraded to 86-89 in about an hour if you do your homework.
Give you three guesses who proudly drives an and has done the ECM upgrade.
Give you three guesses who proudly drives an and has done the ECM upgrade.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
just an fyi, you can send your 85 harness to www.jimsperformance.com and for @ $125-$150, he will repin it to match the 86-89, replace broken connectors, add or replace wires that you might require and do a diagnostic on the harness.
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Melting Slicks
Joined: Apr 2007
Posts: 2,616
Likes: 111
just an fyi, you can send your 85 harness to www.jimsperformance.com and for @ $125-$150, he will repin it to match the 86-89, replace broken connectors, add or replace wires that you might require and do a diagnostic on the harness.
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
just an fyi, you can send your 85 harness to www.jimsperformance.com and for @ $125-$150, he will repin it to match the 86-89, replace broken connectors, add or replace wires that you might require and do a diagnostic on the harness.
And now the rest of the story: A CalPac from the Chebby Sto cost me $75.00, a new chip was $6.00 and $350.00 ( this is a WAG) for the hardware and software to program the chip.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
the biggest differences I found when doing something as simple as upgading the headlights on my 87 to a 92, or three wire to two wire , was that the color codes on the wiring had changed. I suspect the differences you are asking about would involve the same issues
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Thanks for the Reply's everyone. The Wiring Harness in my 88 is kinda hacked up plus it is from a 4+3 car which I want to Change over to a Automatic since i'm going to Race it regularly. Isn't the Wiring for the Trans merged in with the Engine Harness? So a 86 to 88 is a safe bet it will be a plug and play deal? Is the Connectors the same where they plug into the Firewall by the Battery and the Bulkhead where it goes through the Firewall into the ECM? THANKS FOR ALL THE HELP Pipe
Le Mans Master
Joined: May 2004
Posts: 5,387
Likes: 534
I'm doing something similar. I'm running a complete bumper to bumper 4+3 harness out of an 86' in my 85'. I've "pinned out" the AIR diverter solenoid and AIR switch solenoid wiring and removed it all. It was done properly so it can be reinstalled if necessary.
Was planning to just run a pulley in place of the AIR pump, block the egr provision in the manifold, and cap the fuel rail as well as eliminate the cold start injector.I've read a few post saying ditching EGR wasn't suggested. Haven't quite made my mind up yet. Guess we'll see what kind of fireworks I get when I hook it all up and try to run some current through it...
By the Bye: Can anyone tell me where the blue wire running off the ESC plug goes to? I checked the 86 wiring diagrams and if I'm reading it right it goes to a knock sensor which also is drawn as a ground. I spliced on a new ESC pigtail only to find that the blue wire runs to nothing once I fished it out of the bundle. Not entirely sure how this could have happened.
Was planning to just run a pulley in place of the AIR pump, block the egr provision in the manifold, and cap the fuel rail as well as eliminate the cold start injector.I've read a few post saying ditching EGR wasn't suggested. Haven't quite made my mind up yet. Guess we'll see what kind of fireworks I get when I hook it all up and try to run some current through it...
By the Bye: Can anyone tell me where the blue wire running off the ESC plug goes to? I checked the 86 wiring diagrams and if I'm reading it right it goes to a knock sensor which also is drawn as a ground. I spliced on a new ESC pigtail only to find that the blue wire runs to nothing once I fished it out of the bundle. Not entirely sure how this could have happened.
Last edited by 1985 Corvette; Jan 13, 2011 at 08:05 PM.
