Engine Wiring Harness Rebuild
11-05-2011, 12:28 AM
#1
Three Wheelin'
Thread Starter
Engine Wiring Harness Rebuild
I searched and didn't find any posts after JohnKoaWood's killer group buy of connectors, so I though I'd show how I did this one for the Spec Car 
Here are few pictures of how it started- pretty bad shape with brittle jacketing and some wires with the insulation cracking also.
Here are few pictures of how it started- pretty bad shape with brittle jacketing and some wires with the insulation cracking also.
11-05-2011, 01:44 AM
#6
Three Wheelin'
Thread Starter
Okay thanks, but sorry one is my limit- too many other projects and it already took me 3 years to get this done 
.
I started by stripping off all of the jacketing and connectors, and stretching the whole thing out on a 1X2 as I went. I also attached a tape measure at the main connector end for reference and took good pictures of all the branch points and connectors with wire colors. Extracting the pins was a PITA and not necessary, it's better just to cut them as close to the connector as you can.
. I started by stripping off all of the jacketing and connectors, and stretching the whole thing out on a 1X2 as I went. I also attached a tape measure at the main connector end for reference and took good pictures of all the branch points and connectors with wire colors. Extracting the pins was a PITA and not necessary, it's better just to cut them as close to the connector as you can.
11-05-2011, 02:10 AM
#7
Rennlist Member
Looks great! John and I have talked about building replacement harnesses, but every model and year is slightly different and it would wind up costing $1000+ just to cover time and material. Not really a winning combination to make money.
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11-05-2011, 02:25 AM
#8
Three Wheelin'
Thread Starter
Thanks Aaron, $1000 would be about right. Other than the connector kit, here are the materials that I used-
McMaster Carr High Temp Expandable Mesh (Braided Sleeve) http://www.mcmaster.com/#braided-sleeving/=esod4h
Adhesive Heat Shrink Tubing- This was the highest temp stuff I could find at http://www.web-tronics.com/
Tools- Should be apparent by the end of the thread.
McMaster Carr High Temp Expandable Mesh (Braided Sleeve) http://www.mcmaster.com/#braided-sleeving/=esod4h
- 8 feet #2656K11
- 10 feet #2656K12
- 4 feet #2656K13
Adhesive Heat Shrink Tubing- This was the highest temp stuff I could find at http://www.web-tronics.com/
Tools- Should be apparent by the end of the thread.
Last edited by kevincnc; 11-07-2011 at 11:38 AM.
11-05-2011, 02:32 AM
#9
Nordschleife Master
I am trying to build up the motivation to redo the harness on my car. Replaced all the connectors but still feel like there are wiring issues elsewhere. I have the LR crank sensor and fuel injector harness, but imagine there are issues elsewhere still.
I am honestly considering just going standalone to get a new harness!
I am honestly considering just going standalone to get a new harness!
11-05-2011, 02:52 AM
#10
Three Wheelin'
Thread Starter
Yep the best way to do this would be for someone else to do it. So after stripping off all of the jacketing, removing connectors, and straightening the wires, I spliced in new wires on the ones that were in really bad shape. Then starting at the far end, I put the sleeve on up to the next branch with shrink tube on each end. It's a little tricky to keep the sleeve from unraveling too much and it helps to loosely cover the ends with masking tape when you're sliding it over the wires. Masking tape around the ends of the wires helps also. Once the stragglers were covered, the groups were joined at the unions, again starting from the far end. Be sure to stretch the sleeve tight before shrinking the tubing with a heat gun.
11-05-2011, 03:27 AM
#11
Three Wheelin'
Thread Starter
The ground wires were actually worse than they look in the pictures above, and I ended up cracking off almost all of the insulation by squeezing them with smooth-jawed pliers. After that they twisted up easily into basically one conductor. I forgot to take a picture before covering them up. The ring terminals were in surprisingly good shape with solder connections intact, so I left them alone.
The Speed/Ref sensor wires were a little more of a challenge. The signal wires were good enough, but the grounds (shields) were corroded at the connectors. I ended up stripping the stiff jacket back as far as I could, and soldered on a good wire to the connector. I used new braided shield to cover up what I removed, and soldered it to the splice where the old shield ended. The remaining foil shields would probably have been good enough without the extra shielding. Sorry pictures aren't in order.
The Speed/Ref sensor wires were a little more of a challenge. The signal wires were good enough, but the grounds (shields) were corroded at the connectors. I ended up stripping the stiff jacket back as far as I could, and soldered on a good wire to the connector. I used new braided shield to cover up what I removed, and soldered it to the splice where the old shield ended. The remaining foil shields would probably have been good enough without the extra shielding. Sorry pictures aren't in order.
Last edited by kevincnc; 11-05-2011 at 04:15 AM. Reason: Added picture
11-05-2011, 09:18 PM
#15
Nordschleife Master
Great info, I think the pictures have motivated me enough to make this a winter project. Going to see if my buddy has a spare engine harness in his pile of parts.. then i think what i will do is buy the 3 replacement harnesses available from LR and just splice those in. Remove all the old insulation to inspect the original wiring, clean off the gooey friction tape and put it all back together.