Confused on wiring in engine bay

[Kats66Pny]

I took lots of pictures before I took it all apart which allowed my hook up most of it back to the way it was, but none of the pictures I have show where the heck these hook up. Since the previous owner made no attempt to make things nice looking, or how its really suppose to look like... it has me lost.

First..are these two wires. Thick black one and think black one. They are bolted to the firewall/little black box thing.

Second is this long black one that is comes from the firewall/black little thing.

Last one is this thin black wire that comes from the middle of the wire bundle that goes from the ignition coil to the distributor.

Anyone have any clue where they all go?? :shrug I know one of those thick black ones, bolts on to the engine underneath.. here.... I think.

 

[cmayna]

OK, I'm confused with these pics. I do see that you are running a MSD coil. Are you running MSD ignition? I ask because I see a red wire connected from the left big post of the solenoid going somewhere towards the firewall. Is there a battery in the trunk?

Typically, + batt cable connects to the left big post (closest to the battery) of the Soleloid.
Typically, - batt cable connects to the engine block via the black bolt you show in your 4th pic.
Typically, there is another large diameter cable going from the right big post of the solenoid down to the starter (unless you are running a mini starter).
Typically, there is a ground braided or regular wire bolted to the firewall next to your heater hoses. The other end of this wire is grounded to the backside of the passenger head or nearby on the block. This insures a good ground between the motor and chassis.

Typically,,,,,,the above are typical. Nothing is set in stone especially when the PO has freaked around with the wiring.

Typically Yours :bowdown
Craig

Here's a pic that I just took of Red's setup. Damn I love my IPhone

 

[Mach1Rider]

Well I will have to go with assumtion here..... :roul
Looks like the battery is in the trunk and its using the chassis as the main ground point.
With the size of the eyelett's on the wire ends, I will have to assume they are all to go to the eng bolt ground point.

 

[Kats66Pny]

Yes, the big thick red cable is the cable that runs under the body to the battery in the trunk. Like how the PO set that one up? lol I eventually want to redo it, but for now.. I'm leaving it like it was since it worked before.

 

[Kats66Pny]

With the size of the eyelett's on the wire ends, I will have to assume they are all to go to the eng bolt ground point.

So what would be the point of having these two wires coming from the left side of the solenoid also grounded/bolted to the engine if the the other black thick cable on the right side of the solenoid is bolted down there as well? :shrug

 

[Kats66Pny]

Took some more pictures... maybe this will help figure things out. :shrug

Thick red one... goes all the way back to the kill switch/battery in the trunk.

This thick black cable goes from the right side of the solenoid to that bolt on the bottom of the engine.

Here's another picture from different angle that might help. The wire bundle has a red wire coming from it that goes to the back of the alternator and some blue & green wires connected to the top of the msd coil.

 

[Horseplay]

Hey Kat,

That thick black wire on the right side of the solenoid goes to the starter, not the bolt on the engine. That would be a direct ground and not good!

Might I suggest you get a copy of the underhood wiring diagram and follow it and not try to figure out how the idiot PO had everything rigged. The only thing that might be different is the distributor wiring as it is not stock but you can get a copy of it's wiring set-up on line if needed.

 

[Mach1Rider]

:roul...more assumptions here.
From the looks of it it has a mini starter, that would be the (black) power cable to it.
The extra ground wire is redundant at the sol, best guess it has a poor ground to the chassis.

Sorry but that is one nasty hacked wiring job. :wth

 

[Fast68back]

 

[Kats66Pny]

This is my starter.........that I have yet to put back in. Forgot about it actually. Was hidden in the corner. :hide

So the big black cable connects to the starter where the bolt is stick out and gets tightened down?

 

[Midlife]

Yes. That is not a starter with an internal starter solenoid, so the diagram up above is incorrect.

 

[Mach1Rider]

Yep, That wiring to the sol is not going to work for the starter or possiably the ign too. :roll

 

[cmayna]

That looks like a regular starter, thus should be wired like the top drawing in the following:

 

[Kats66Pny]

Answering here...

Big red wire: What gauge is being ran all the way to the trunk?

I have no idea what gauge it is.


What other wire identification issues do you have besides that single black wire that goes parallel with the big black wire going to the block?

Other than that single black wire... I believe that's it for the bay area.

 

[Mach1Rider]

The black wire your thumb and fingers were on in your pic's is the starter wire to that bolt on the rear.
The other black wire bolted to the sol mount goes on the lower bolt at the eng block.
I suggest you move the other end to a better chassis grounding point, Try a clean spot on one of the shock tower bolts.
The extra thin black wire with it is an :shrug

 

[Kats66Pny]

The other black wire bolted to the sol mount goes on the lower bolt at the eng block.
I suggest you move the other end to a better chassis grounding point, Try a clean spot on one of the shock tower bolts.

Move the end of this big black one?

 

[Mach1Rider]

Yes, the small bolt it is attached to now may not be a good ground.
With the batt in the trunk and the batt ground with attached to the frame,
A better frame grounding point in the eng bay may help when you are cranking the eng.

 

[Horseplay]

Kat,

Both of those black wires (big and small) were used as grounds as you have the other connected ends screwed to the chassis. The heavy gauge wire should be used as your engine ground and yes it should have a better connection than currently shown. You probably do not need to use the small wire as it is just redundant. The way the PO put your car together he more than likely had lots of electrical issues as was just cobbling things together to make something work. Hence the extra wires.

You need to make sure that HOT lead from the trunk is heavy enough to handle the load of the starter. Routed through the cabin it could become a fire hazard if undersized.

 

[cmayna]

Kat,
There is no stamping or markings on the big red wire to indicate the gauge? It looks too small to me for what is being demanded from it. Yes replacing it would be a major PITA. No it's probably not that critical do swap out for a 1-2 gauge wire right now but I would at least consider doing it this winter.

 

[Kats66Pny]

Nope, no markings or anything on it. It has to be changed out eventually when I reroute it later on in the future. It's going to be too short for what I want to do.