How long should it take to remove old and install new engine wiring harness on a 66? Using Lectric Limited harness and headlight extension. Having it done for me by a mechanic with lots of experience on older classics.

 

Took me less than 2 hrs...its a fairly easy job.

 

DUB

 

I did mine not to long ago....my first time..it took about took about 3 hours..start to finish...all grommets installed and wire supports,replaced...

 

couple o hours about right be sure to use conductive grease on all connecters

 

I would guess 3 hours easily to remove the old and replace. That would be taking a little extra time to work carefully to avoid scratching paint or maring under hood components.

 

A pleasant Saturday morning task that will make your car safer and better...

 

Any tips or tricks?

This is next on the list, since brakes are done. I remember years ago when I tried to start it last, as the engine was turning over, there a puff of smoke that came up around where the starter was. A new engine harness was then on order. Didn't want to take any chances with 50year old wiring.

Is the a certain place to start? Any need to take pictures of how the current harness is installed? Can it be done all topside without having to get underneath or Jack the vette up? Do you take the old one out completely and then put the new one in or put the new one in as your taking the old one out?

 

this is something to consider....for me I jacked the car up....and started at the starter...you said you had a puff of smoke there....might be time to do starter and soloniod R & R,,,but my point is...I found install the wires on the starter in place is a challenge especially if your laying on your back....its hard to get there with exhaust on...so then I wired up the started not installed....

If I had the car on a lift and standing would have been much easier for starter hook up......but the rest of the wire replacement is very easy

install the starter,,,( pull remaining harness up, or push extra loom below)and very carefully route the wires to get as much Clarence as possible from exhaust...HUGGING THE BLOCK...easy to burn them if not really routed and placed and pushed into certain areas to make sure they stay in place and don't move later...... while driving resulting melted /burned up loom @ starter ruining a new loom

 

Three hours is probably more reality especially if you have ignition shielding that needs to be removed to get to the starter. Also taking the headlight rims off to get the wiring harness out of there sometimes could be a challenge, and to get the plugs properly on the headlight extensions. If you're lucky Letric limited change their supplier for their plastic plugs because they're old ones used to break off in your hands when you put them together they were way too brittle.

 

Yeah, I think I am going to remove the starter and solenoid to inspect and either shelf and rebuild when it's restored and buy a replacement or have it rebuilt now.

How did they install the engine harness at the factory? Did they attach to the starter first, then drop the body on and then route and hookup the rest?

 

I honestly feel that the starter was NOT on the engine and it was installed when the body came down, The reason being...On the 1977 (I believe) to 1982 Corvette. GM used a wiring harness that WAS attached to the starter with a plug on the end of the harness and all they had to do was plug it into the main engine harness...so it save them time. That was great idea for time savings...but for electrical connections...that was NOT a good idea due to getting dirty can causing problems.

This is what that GM connector from the starter basically looks like.


Close up of connector:


DUB

 

I removed the engine harness connector at the firewall and it's not too bad, just what looks like blueish powder. Quite surprised the connector didn't break off, the tape around the wires was breaking off in pieces it was so brittle.

Before I connect the connector from the new harness to the firewall connection, is there something I can put on there, like dielectric grease or something, or just take a soft bristle brush and clean and vacuum it as much as possible?

Also, it looks like there are 3 black ties on the vendor which hold the harness wires going to the alternator/VR/horn relay areas. Can these be saved, meaning can they be unhooked to reuse again? They appear to be attached through the fender wheel well. Or are they just cut and new ones used?

 

Gently clean the firewall connector using electric contact cleaner and a soft brush...you don't want to bend the tangs. Clean as thoroughly as possible, and then apply dielectric grease to the tangs. As to the three plastic retainers, if you can pry the originals apart without breaking them, I would attempt to reuse them. The stud that goes into the fender well on the reproductions, in many cases, are too small and don't stay in place very well. I had to get mine from three different suppliers before I found some that had a large enough stud to stay in place. Take your time and this will be a very satisfying project

 

It may be me being slower than average, but whenever something was supposed to take 3 (or any number of) hours I usually ended up at double that, cause there was always something else showing up while doing the job

 

I also agree with carefully cleaning your firewall junction area and than using dielectric grease.

When cleaning the terminals...make sure you take the TIME to actually understand what surface of the tang in the firewall junction area you need to be making sure are clean.

If you have not done so...taking the time to understand how the terminals meet up can and make a good positive contact with each other is important. These terminals when joined are under tension due to their shape...so simply assuming that they are all good can cause for the terminal or terminals that are not tight with each other...in conjunction with how many amps that circuit is providing can cause for a resistance and actually cause for that area to get hot and possible melt.

NOT meaning to put fear into your project...just trying to make you aware. Often times the circuits that can cause for terminals to get hot and melt are those are generally circuits that command a lot of amps...and by 'a lot'...I am generally referring to circuits in the range of 25 amps+. Any circuit regardless of amp draw can get hot if it is not making good solid contact.....but if the amps are low ..generally so is the heat.

I have felt the 20 amp fuse in the battery box are on a 1982 that supplied power for the computer and fuel pump relay,etc...and I have felt them and sometimes this fuse holder is HOT...but not to the point of being able burn me or melt the plastic fuse holder GM used. And what caused that heat was the fuse itself was dirty and not making good contact...even though it was able to still supply power to the components in that circuit.

What might take someone like me to do something can easily escalate to an insane number of hours due to so many potential problems can show up.

DUB