C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1986 Corvette wiring harness

Thread Tools
 
Search this Thread
 
Old Jan 17, 2018 | 10:31 PM
  #1  
Rob86's Avatar
Rob86
Thread Starter
8th Gear
 
Joined: Nov 2017
Posts: 8
Likes: 0
From: Clarksburg West Virginia
Default 1986 Corvette wiring harness

Quick question for the "gurus" of C4 Corvettes....
Recently purchased 1986 C4 Corvette coupe with a "stray" five (5) pin harness located to left of power brake booster. Originates at firewall and
appears to be at the top of a stack of other harnesses. Length about one foot long. Not mentioned in the Haynes Manual or
diagrams I have located of the engine. Car has approximately 94,000 miles.
Thanks in advance.
Reply
Old Jan 18, 2018 | 01:25 AM
  #2  
VikingTrad3r's Avatar
VikingTrad3r
Oil Producer
Supporting Gold
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2014
Posts: 9,368
Likes: 2,735
Default

hi there. can u post pics?
Reply
Old Jan 18, 2018 | 02:47 AM
  #3  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,389
Likes: 2,741
Default

There's 3 relays that have 5 pin connectors that could be considered 'in the vicinity' maybe. All have cavities A, B, C, D, E. If you mention the wire colors @ the terminals it could ID the connector.

Have you located the cooling fan relay that hangs on the rear wheelhouse shield on an '86 I believe? How about the mass airflow relays higher and I'd consider more in the vicinity of the cruise servo above the jump block behind battery tray.
Reply
Old Jan 18, 2018 | 09:04 PM
  #4  
Bwbob's Avatar
Bwbob
Instructor
 
Joined: Oct 2015
Posts: 134
Likes: 6
From: Osceola WI
Default

sounds like a MAF burn off relay or power relay. Any mods that someone may have done to eliminate or upgrade the MAF?
Reply
Old Jan 19, 2018 | 09:41 PM
  #5  
Rob86's Avatar
Rob86
Thread Starter
8th Gear
 
Joined: Nov 2017
Posts: 8
Likes: 0
From: Clarksburg West Virginia
Default

Thanks all respondents...1. I do not have the capability to upload pictures at this time. 2. the MAF burn off relay and the power relay seem to be connected at the firewall. no indication of
any mods, etc. or upgrades to the MAF, etc. that I can find.
3. the wire colors are as follows. A= Blue; B=Tan; C=Black; D=Light Blue; E= Lime/Light Green. No id number on the connector except the possible wire size being "14". Letters "PED" on
plastic spiral wrap covering of wires.
4. The connector has a square opening for the pins and tapers back in a triangular shell.
I considered it to possibly be an additional connector for a later model C4 that the Haynes Manual depicts as having the ECM mounted at the rear of the engine compartment above the
battery and in front of the left hand hood attachment mount.
5. Cooling fan relay found on fender well (hanging loose like some other items scattered about the engine compartment).
6. Possibly the cruise control connector as it did not work while driving from Effingham, IL to Tara Haught (sp), IN. before finding a car carrier to complete the trip.
More fun to be had as the project creeps forward...weather permitting. Thanks again.
So far the experience(s) on corvettforum have been most enjoyable and educational..especially as the car is a CORVETTE and a very fine example of American innovation and abilities.
Once it is in ones' blood, as my wife says, its there to stay.
Reply
Old Jan 19, 2018 | 09:59 PM
  #6  
Benny42's Avatar
Benny42
Drifting
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2006
Posts: 1,423
Likes: 96
From: Magnolia Tx
Default

That is the location of the cruise control servo and i think that is the number of pins on the plug. Does your cruise control work? (If so would prove me wrong)
Reply
Old Jan 19, 2018 | 10:10 PM
  #7  
Rob86's Avatar
Rob86
Thread Starter
8th Gear
 
Joined: Nov 2017
Posts: 8
Likes: 0
From: Clarksburg West Virginia
Default

Thanks very much. I am researching that at the moment. The cruise control is not working and did not work on the short trip home.
Reply
Old Jan 19, 2018 | 10:12 PM
  #8  
RWDsmoke's Avatar
RWDsmoke
Drifting
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Liked
 
Joined: Jan 2005
Posts: 1,354
Likes: 325
From: San Antonio Tx
Default

Those are the correct colors for the cruise control connector.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-1

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-2

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-3

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-4

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-5

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-6

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-7

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-8

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-9

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
Old Jan 20, 2018 | 12:21 AM
  #9  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,389
Likes: 2,741
Default

Originally Posted by RWDsmoke
Those are the correct colors for the cruise control connector.
Yes they are. OP - looks that's a done deal!
Reply
Old Jan 21, 2018 | 03:14 PM
  #10  
Rob86's Avatar
Rob86
Thread Starter
8th Gear
 
Joined: Nov 2017
Posts: 8
Likes: 0
From: Clarksburg West Virginia
Default

Thanks folks....been busy clearing the place of snow! Now to find the replacement cruise control dashpot or whatever was taken off the car before I bought it.
From all I have seen on this car I believe it to be an "abused child"! Just thankful that Spring, 2018 may be out there somewhere.

Thanks again for the assistance. Great folks on the forum.

I will keep you posted as time marches on.
Reply
Old Jan 28, 2018 | 09:45 PM
  #11  
Rob86's Avatar
Rob86
Thread Starter
8th Gear
 
Joined: Nov 2017
Posts: 8
Likes: 0
From: Clarksburg West Virginia
Default

Originally Posted by Rob86
Thanks folks....been busy clearing the place of snow! Now to find the replacement cruise control dashpot or whatever was taken off the car before I bought it.
From all I have seen on this car I believe it to be an "abused child"! Just thankful that Spring, 2018 may be out there somewhere.

Thanks again for the assistance. Great folks on the forum.

I will keep you posted as time marches on.
Thanks folks. It (the harness connector) is indeed a part of the cruise control apparatus. The entire cruise control system short of the lever on the steering wheel was removed from the area above the battery. Probably sold off the car or removed by the previous owner. So the search for the missing parts is on. post as of 1/28/18 2144 hours.
Reply
Old Jan 29, 2018 | 12:19 AM
  #12  
xrav22's Avatar
xrav22
Drifting
10 Year Member
 
Joined: Mar 2013
Posts: 1,952
Likes: 239
From: Venice Cali.
Default

Reply
Old Jan 29, 2018 | 07:11 AM
  #13  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,389
Likes: 2,741
Default

Here's typical L98 'under-hood' components so you can maybe inventory yours.

Name:  L98 Cruise.jpg
Views: 11020
Size:  101.9 KB Name:  L98 Cruise (2).jpg
Views: 2704
Size:  98.5 KB

Last edited by WVZR-1; Jan 29, 2018 at 07:30 AM.
Reply
Old Jan 29, 2018 | 09:42 AM
  #14  
Rob86's Avatar
Rob86
Thread Starter
8th Gear
 
Joined: Nov 2017
Posts: 8
Likes: 0
From: Clarksburg West Virginia
Default

Thanks so very much. A great help on this one of several "opportunities" with this C4.
The diagram and parts list will go a long way toward sorting this out. Thanks WVZR-1.
The photograph greatly assist in knowing just where the items missing will be refitted to. Thanks xrav22.
Very much appreciated everyone.
Reply

Get notified of new replies

To 1986 Corvette wiring harness





All times are GMT -4. The time now is 07:02 PM.

story-0
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-1
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-2
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-3
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-4
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-5
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-6
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-7
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-8
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-9
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE