Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hi all,

I recently purchased my first ever corvette ('86 targa) and have so far been loving it. The only problem I have is that the previous owner did a fair bit of work on the wiring harness and did a pretty terrible job at it (low quality loom, bad crimps, use of cheapo spade connectors, etc etc etc). Thus I'm looking to completely redo the harness (starting with the engine bay) in a professional way (spec 55 wire, raychem sheath, mil-spec connectors, the whole nine yards). I've done several wiring harnesses as a member of our schools FSAE team (2x for car and 1x for dyno) so I know about harness manufacturing and have access to good crimpers etc.

I just mostly want to know:

a) Has anybody around here done this before? If so, what kind of cost/time commitment did you have to put into it? I was planning to budget ~1.5-2k and 1 month of car downtime for the project, which seemed about right from my experience on the formula car (where we spend about $750 and get it done across a weekend).

b) Is there any kind of drawing of the stock harness with pinouts, section lengths, mounting points, etc? It would really make my life easier if the lengths were already known so I dont have to go through the trouble of making up a rope harness.

Any thoughts would be greatly appreciated.

Thanks!
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #4 ·
The factory service manual (FSM) for your car contains all the circuit diagrams , connector pin outs , etc.
Thanks! I hadn't thought about the factory manual (I've got the Haynes manual but the information in it about wiring is a little sparse). Just one question, do you know if the FSM has wire lengths in it? Having the factory wire lengths would make the whole process about 1856513x easier, so thats mainly what I'm trying to chase down now (if this information even exists).

www.jimsperformance.com will rebuild it to stock for $150, call Jim
I originally looked at the idea of having somebody rebuild the harness, but I decided against it. Mostly, it was because I'd like to know what components are put into it (I'd like it to be close to a professional motorsports harness in terms of parts/quality) . However, I also like working on wiring/electrical systems, and this also seems like a good project to get to know more about all the various parts and assemblies of my 'vette. I'm not nearly as mechanically inclined as I am electrically, so I should be able to tackle this project while still learning all the mechanical bits I'm not so good at.
 

·
Registered
Joined
·
128 Posts
do you know if the FSM has wire lengths in it?
Mine does not.
My harnesses were in bad shape. I used a razor blade to cut the wrap and found the insulation literally fell off some of the wires from heat and age. At that point there was no turning back, lol.
I ended up running new wire one at a time, then removing the old. Once the entire harness had been replaced, I re-wrapped it with Scotch 66 and stuffed it into new hi-temp plastic wire loom.
I re-used most of the connectors by clipping the wire 1" from the connector, soldering the new one on to the pigtail, then heat-shrinking the splice. All you see is the heat-shrink from the connector into the loom, came out pretty good looking.
 

·
Premium Member
Joined
·
2,106 Posts
Thanks! I hadn't thought about the factory manual (I've got the Haynes manual but the information in it about wiring is a little sparse). Just one question, do you know if the FSM has wire lengths in it? Having the factory wire lengths would make the whole process about 1856513x easier, so thats mainly what I'm trying to chase down now (if this information even exists).



I originally looked at the idea of having somebody rebuild the harness, but I decided against it. Mostly, it was because I'd like to know what components are put into it (I'd like it to be close to a professional motorsports harness in terms of parts/quality) . However, I also like working on wiring/electrical systems, and this also seems like a good project to get to know more about all the various parts and assemblies of my 'vette. I'm not nearly as mechanically inclined as I am electrically, so I should be able to tackle this project while still learning all the mechanical bits I'm not so good at.
PLan well before you start. Little things will creep in.. The VSS sensor is not a standard weather pack. some old school stock plastic parts of the connectors are really hard to find-- think about upgrading the sensors and relays also (oil pressure/temp/ Fan relay etc.)

Skip the in cap coil TPI and go the the design for the 89 trans am (external coil)
If you plan on upgrading the injectors and custom tuning -- odds are you won't need the cold start injector.

even with the field manual -- don't count on it being 100% correct..
Plan on running a few extra grounds-- just because..

If you go to the rear harness-- the tank cradle is aluminum, and you need to run the grounds up to the steel frame by the wheels

Just some thoughts before coffee...
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #8 ·
Made the mistake of thinking the thread had died after my last post. Guess I wont do that again :laughing:.

PLan well before you start. Little things will creep in.. The VSS sensor is not a standard weather pack. some old school stock plastic parts of the connectors are really hard to find-- think about upgrading the sensors and relays also (oil pressure/temp/ Fan relay etc.)

Skip the in cap coil TPI and go the the design for the 89 trans am (external coil)
If you plan on upgrading the injectors and custom tuning -- odds are you won't need the cold start injector.

even with the field manual -- don't count on it being 100% correct..
Plan on running a few extra grounds-- just because..

If you go to the rear harness-- the tank cradle is aluminum, and you need to run the grounds up to the steel frame by the wheels

Just some thoughts before coffee...
I hadn't planned about doing any kind of upgrading besides the harness itself (and potentially relays/fuses/power dist).

Is there a distinct advantage to having the coil external to the dist? Also, is it a difficult process to install the Trans Am style coil? I can't say I've ever seen one and google is yielding no useful results.

After just a cursory glance I had actually assumed that the VSS was just a standard weatherpack. Thanks for pointing that out. Do you know of any other sensors with weird connectors?
 

·
Registered
Joined
·
414 Posts
ON my 84' i redid the wiring to the TBI's, took me about an hour(had to take a break!) and maybe cost $40, the most expensive thing was the wire, we had everything else.


If ya need any help just ask, im just a hop and a skip away from Norman! ive been dying to take the 'vette on a little road trip!:devil:
 
1 - 9 of 9 Posts
Top