Now that the front clip has been installed back on the Corvette, and most of the trim features fitted in place, my attention turned toward reinstalling all of the electrical
harnesses and vacuum lines in the engine compartment. To say this was a challenging task would be an understatement - it
was like putting together a giant 3D jigsaw puzzle!
I can't stress enough how important it is to have a good photo record of how
everything was installed before you disassembled it. In addition, I recommend
tagging every connector and component using an index card and zip tie with a brief description and photo number
on each tag as outlined in my tech article
Simple Car Restoration Tips". I'm convinced that this practice was a
huge part of my ability to successfully complete this task. In my opinion the illustrations in
the Corvette Assembly Instruction Manual (AIM), and the other manuals I have, just
aren't detailed enough to allow the wiring harnesses to be reinstalled without
That said, as is often the case my work started by cleaning up what came off the
car. In my case the harnesses were caked with dirt, grease and grime and were
also covered with overspray from a past paint job gone wrong. Here's an example of what I
Following a cleaning using good old soap and water I set to work cutting away
the old tape. After thinking about it for a while I decided that replacing the
tape was a much less daunting task than trying to clean it. To keep the wires
properly aligned I did this work a little at a time. I would remove several feet
of tape, clean the wires using a rag soaked in lacquer thinner, and then wrap
new high quality electrical tape around the wires. It was a tedious process, but
it worked well.
Keeping the tape tight and the wires bundled tightly together are important
as you re-wrap the wiring harnesses. Also, try not to leave any ends of the tape
exposed. If you have to cut the tape for whatever reason (I tried to avoid it)
when you start wrapping again run the tape back over the starting end of the
tape so that it doesn't unravel over time. I also learned that, while it's
good to pull the tape nice and taught as you wrap the wires, it's best to use
very little tension where you end and cut the tape. If you stretch the tape near the
cut ends the tape will pull away and come loose over time. Leaving the tape
slack at the ends will provide a better seal and will make the end less likely
to come unstuck over time (learned this from experience).
Once the wire harnesses were cleaned up and taped I realized that the
factory-installed rubber coating at the fuse block was very deteriorated
exposing many of the wire ends and terminals. To resolve this a bit of liquid
electrical tape was applied to the fuse block to get everything sealed up nice
and water tight. It worked really well. You can buy liquid tape at most hardware
or home improvement stores.
And here's the finished product - just one of several wiring harnesses that
needed a lot of TLC. I found that maintaining the tags was difficult during the
cleaning process so I actually ended up temporarily removing them and
reinstalling them one at a time while the harnesses were cleaned. It was a lot
more work to do it this way, but when it came time to install the harnesses I
was thankful to have the tags as a guide.
Obviously there are many components under the hood that the wiring and vacuum
lines connect into so I spent some time cleaning up those items too. These
included the windshield wiper motor, wiper door actuator, coolant reservoir,
vacuum reservoir, and windshield washer bag. Obviously not all of these are
included in the electrical and vacuum systems, but installing them before all those wires
and hoses went in seemed like a good idea.
Once everything was cleaned up and ready to go I set to work installing the
wiring harnesses and getting the wires routed. The first step was to install the
fuse block on the interior side of the firewall.
Once installed I applied some dielectric grease to the terminals and bolted
the engine-bay side of the harness in place. This is when the "fun" really started...
Initially I roughed out the routing of the wiring and vacuum hoses, positioned
them where I thought they went, and verified all of the
wires and hoses could reach where they needed to go. This actually took quite a
while - even using the tags and photos I had. There was a lot of trial and error
to the process.
This is how I spent about six weekends over the course of the summer -
examining photos, connection details, routing paths and other relevant
information visible in the hundreds of wiring photos I had taken. Again, having
all of these photos was a huge help!
One thing I noticed in my photos was that the headlight vacuum relays were
mounted directly to the hood surround header bar when I bought the car. However,
at the factory they were mounted to a metal plate which was then bolted to the
header bar. This plate positioned the relays closer to the nose of the car and
helped to hide the relays and associated tubing. I was really striving for a
clean installation here so I fabricated a new plate out of some plate steel that
was laying around my garage.
After about an hour of work I had a replacement plate finished and ready to
Many hours and countless zip ties later here's what I ended up with. The routing
scheme isn't quite factory, but I think
it's a clean arrangement. For instance, I tucked the wires behind the
windshield washer motor, used many zip ties to keep the wires and hoses bundled
together, and did my best to keep the arrangement very compact. As a result
there are now some J-clips that really don't serve much of a purpose now. I'll
probably end up removing those before dropping the body onto the frame since their function has been replaced by
all the zip ties that were used. Note that the various hanging wires and hoses connect
to the engine so those have been left as-is for now.
Ignore all of the dust. I forgot to blow everything off before I took these
I was surprised to see how well the wires cleaned
up. Soap and water hardly put a dent in the grime, but a lacquer thinner soaked
rag worked really well.
Note that I used plastic zip ties instead of the original ties. Zip ties are
cheaper and less visible in the finished product. Just don't over-tighten them
on the vacuum lines or you'll pinch the lines shut and the headlights will
operate very slowly, or not at all.
I spent quite a bit of time dealing with the wires and hoses near the nose of
the car. I really didn't want to see them so I worked hard to get them hidden.
Notice that I got rid of the original plastic ties along the header bar and used
some rigid plastic clips instead. This allowed me to tuck the wires tight to the
underside of the hood surround and then bolt them securely in place. This worked
great and came out looking really clean!
Some shots along the passenger-side fender. These are mainly air conditioning components.
The installation of these
will be covered in my next update (consider this a sneak peak)!
This area was a real challenge. Hoses, wires and lines everywhere! I must
have tried tweaking the arrangement of the lines 20 different ways and went
through a ton of zip ties in the process - route the lines, zip tie in place,
view the result, decide to tweak it, cut the zip
tie, repeat. All in all I think it came out well though.
And there you have it! The wiring harnesses and vacuum lines installed and
ready to be connected to the engine - one more update done and in the books. In
my next update I'll be documenting how I retrofitted the original Freon-based
air condition system to work with R134a refrigerant and the installation of the
various heating and cooling lines. Hopefully I'll have the next update posted by
If you have any questions on the routing scheme I used for the vacuum lines or
wiring harnesses feel free to post a
question over on the
Corvette Restoration Forum and I'll do my best to provide an answer or
additional photos. Also,
if you haven't done so already, please
Like this project on Facebook to receive additional progress updates and
notifications when updates have been posted. The page has nearly 800 likes so
far and growing - wow!