re-harnessing '86 CGT, friedness question

[auditude at cox.net]

Hello,

I am in the process of doing some work to my Coupe GT.  I have replaced the control arm bushings and am now looking at replacing the cold start valve's wiring harness.

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The wiring harness in question is the one that includes the wiring to the cold start valve.  It also is the one with the wires to the starter and oil temp sender.  I scavenged all the wiring from my previous wrecked Coupe GT, so I have that harness and am reworking it to install it in the current car.

As usual, the starter wires are all corroded and fried so I'm splicing in new sections.

It looks like the harness routes under the airbox, behind the battery, eventually leading to the underdash area in front of the driver.  Then it gets all crazy with branches and stuff that I can't seem to untangle to my satisfaction.

There is just so much stuff going on at the dashboard side of the harness that it is hard to make it look neat.  I don't think it needs to be neat to work, but I'll do what I can before I put it in.

I'm thinking I should go through the firewall from the engine side, rather than out from the cabin.  Everything, all the connectors, look like they can fit through the medium-sized round hole that the grommet/boot thing plugs once in place.

This is good practice for my MC swap into the 4ksq that is coming up.

I considered relaying the starter, but I don't know if I want to bother with that right now.  The new wires should be enough, unless someone has a compelling reason why I should do that.  It seems the failure mode is the insulation hardening and cracking, exposing the conductors to the elements to corrode and look ugly.

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Oh yeah, the point of my post.  The cold start valve wiring harness was fried near the battery, and the cold start valve wasn't connected when I bought the car.

I don't know why the harness would be fried.  Isn't stuff fuse protected?  Assuming the cold start valve shorted or something, I would think a fuse would pop somewhere before wires would get so hot they melted the insulation and plastic sheathing.

I would like to understand why it was melted before I put in another harness.  I don't want the new harness to melt the same way.

I'm thinking perhaps battery acid got on the wiring harness and melted the insulation, or perhaps it was somehow pinched.  Admittedly, I really have no clue as to why it is fried.

It is fried on the inboard side of the battery tray, near where the ignition coil and such is located.  Some of the wires continue to their devices, with the exception of the cold start valve wires and possibly others.

Is there any testing I can do to see what fried it?  Is the cold start valve a 12v device?  I've hit it with 12v many times by now, trying to get it to start when cold and back when I bought with a unknown missing CIS "spare" fuse.

Perhaps to be safe I should just swap in all the sensors from my old Coupe GT engine along with the harness.  But I'd rather not if I don't have to.

Any info or comments are appreciated.

Later,

Ken
'88 5kcstq
'86 Coupe GT
'85 4ksq t2b
'87 5k t donor
'94 SL2