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Discussion Starter · #1 ·
Hey there, SNS people! Working on a temporary solution for a wiring harness to get my car running well enough to charge and drive without catching fire. I have removed the entire factory harness under-hood from firewall connector forward and am trying to wire it up to drive it to a new location as I do not have access to a trailer at the moment. I have an externally regulated alt, Hitachi mini starter, HEI dist and mechanical fan so not much to work on for wiring. Voltage regulator, horn relay, alternator, starter, ignition (12VDC). Any help would be greatly appreciated. I still have the orig harness which I have separated into the upper (lights) and lower (charging and ignition/starting) and am trying to painstakingly repair it but it has been so butchered and hacked over the years, it is a daunting task. I have the AAW kit for later but I really do not feel it prudent or wise to temporarily install any part of that nice new setup.

Thanks in advance,

~Andy
 

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Off of the battery positive post you will have a large cable/wire that will go down to the starter

Off of the battery negative post you will have a large cable/wire that will bolt to a clean spot on the block

Off of the battery positive post you should have a smaller gauge fusible link wire that attaches to a junction stud on the backside of the radiator support.

Off of this same junction stud you should have a 10 gauge wire that goes over to the passenger side headlight area and there this wire needs to be split to where one leg of this split will go to the proper external voltage regulator connector, another leg going to the output stud on the alternator, and then the third leg going to the horn relay buss.

Off of the horn relay buss you should have a fusible link wire that attaches to a 12 gauge wire and this wire goes to and through the bulkhead connector to the interior wiring such as the ignition switch, fuse block, headlight switch and such.

You may have to add a ground wire between the battery negative post and the fender and/or a ground wire between the engine and the firewall.

On the external voltage regulator there are 4 connections with one being a battery positive connection covered in the above info and then the remaining 3 have 2 of them going to the proper spots on the externally regulated alternator and the last of the 4 going to a specific wire out of the bulkhead connector that then goes inside the car and wires to the ignition switch and dash GEN light circuit.

Now all that's left to get the motor to crank over with the key is to find the cranking 12V wire out of the firewall bulkhead connector and attach that to the solenoid activation terminal on your starter.

Since you are running an HEI you cannot use the factory resistance wire out of the firewall bulkhead connector so you need to find that wire and cap it off and then run a fresh wire from the BAT terminal on the HEI through the firewall and plug it into the fuse tap marked IGN.

Once you get the car where it needs to be disconnect the battery just in case.

Jim
 

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Discussion Starter · #3 ·
@Custom Jim I was going to ask you directly. That's funny!! I saw you on the sidebar when I was writing my question. Thanks so much for the info. I have a stand-alone switch panel I have mounted to the dash for temporary use until I get things in order so it's really going to be much easier than digging through the existing tangled spaghetti under the dash to get my ignition switch working. I have a new steering column going in but I don't want to install anything new until I get my welding and grinding/painting finished so, the old one is hacked to bits.

So with all you stated above, I have the batt pos to the starter directly from the batt, the batt neg directly to the block and chassis, the switched starter solenoid wire to the front that's going to be wired to a relay then to a momentary push-button switch on the dash panel but I think I have the rest worked out from there with all you have given me above. I only need a very simple charging and starting circuit. I know I'll need a switched full 12VDC lead directly to the HEI from somewhere (voltage reg or J-block from there like the horn relay), the relay from the solenoid to the switch at the dash, I have three other switches in that panel so I'm going to have one of them for the 12VDC to the HEI so I have ignition on/off. Mech fuel pump so still good with that for now, just trying to figure out how to wire it up for a short jaunt across town in the daylight hours. I can rig up brake lights so that's a non-issue. Any idea how I should endeavor the relay from the solenoid to the momentary on the dash? I don't have much if any experience wiring them.. I have a 30A 4-pole and a 40A, 5-pole relay at my disposal with the female connector wired for either.

Thanks again and sorry for the long diatribe. Just the rambling thoughts of a Bowtie madman.. :p
 

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Discussion Starter · #4 ·
Why I'm hesitant to use any of this wiring even for temporary use at all... Friggin' dangerous! Some of them were warm to the touch before I pulled them so.. warm wires are no good...

Motor vehicle Electrical wiring Electricity Gas Cable

Purple Electrical wiring Circuit component Computer hardware Audio equipment
Electrical wiring Gas Cable Auto part Wire
 

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Discussion Starter · #5 ·
Just a cheap-a$$ switch panel that was in a box I found... Guess it'll finally come in handy.. lol. Ugh. Bent up some flat stock aluminum for mounts and bingo!
Land vehicle Grille Automotive lighting Automotive tire Hood
 

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Why did I think all of the typing or pecking in my case did I think there was a big variable like you having a switch panel ?

How important is having the alternator working ?. If it needs to be driven further than what the battery can supply to get you there then let us know. If it's a short drive but the car may be needing to be moved or started a lot, throw a charger on the battery to keep it up.

As ar as other things a constant will be you having the large battery cables going to the starter and the block as well as grounds to the fender and/or firewall.

Since we now know about this switch panel and how messed up the wiring is you need to gather some things.

I would find you a 10 gauge fuse holder to where a 30A fuse can be put into it.

Connect one end of this fuse holder to the battery positive post and then with a 10 gauge wire off of the other side of this fuse holder route that to inside the car.

This "Power" wire will feed the panel and may just have one power input.

On the panel there is a starter button and the output of that will need to have a 12 gauge wire attached to it and routed to
the starter solenoids activation terminal.

You can then probably run off of the output of the switch marked ACC1 to power your HEI and use a 12 gauge wire between this switch and the terminal marked BAT on the HEI.

To start the car probably will require the far left switch to be turned to ON, then the ACC1 switch turned on to power up the HEI and then by pushing the round button should get the motor to crank over and the engine should run.

To shut the car off one could turn the far left switch off or the ACC1 switch off as this should stop power going to the HEI.

All of this will get the car to run and drive BUT if you want things like brake lights, turn signals, headlights, and so on, you might want to put the right harness in and then take it where it needs to be or get a trailer (or even rent one).

MAN, what a cluster with what looks like hot melt glue over the one switches terminals.

Jim
 

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Discussion Starter · #7 ·
MAN, what a cluster with what looks like hot melt glue over the one switches terminals.
Thanks, Jim! Yeah, the wiring from the PO was a friggin disaster! Putting it mildly for sure. I tried to trace some of it back and got lost with the speaker wire and hot-melt so... under hood, it's no better with different colored wires spliced into the harness at different locations, kinda just used what he had on hand I guess... not even going to try wasting any more time on it. I have all the wiring set up for power and will follow your lead (lol) on the verbal diagram above. I am going to try and get the alt to function as I don't know how much driving i'm going to be doing but, really the HEI will be all that's needing power once the starter fires the motor and that's very little amp draw from the battery besides the brake lights when needed (I can wire those no prob off another jump from the power at the panel to the brake switch then to the tails, wired directly). I have a good fresh 900 CCA battery with a full charge in it so it should power me for a few miles... at least :p As for the switch panel, sorry I didn't make that initial statement in my entry. Details, details... right? FML! Do you think it would be necessary to have a relay wired for the solenoid switching from the momentary or would that not cause enough resistance with a 10G wire to and from it to cause any overheating/melting issue just wiring the momentary directly to the solenoid without the relay? It'll fire immediately each time, as this motor is fresh and the ignition and carb are pretty dialed in. Before the ring gear replacement, when it DID catch a few teeth, it fired on less than one full 360° spin with two pumps from the go pedal.
 

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@Custom Jim are these about right for what I need? I can adjust the wiring as necessary to get power for my temporary circuits
View attachment 431459 View attachment 431460
Basically, yes this is what is needed.

Just be careful as the MAD stuff is a guide but lacks info in area's for the novice.

On the diagram with the 10 and 12 SI alternator, there is no protection on the circuits. One needs a fusible link, fuse, or properly sized breaker on the wire between the battery and the junction block near the battery.

On my 68, there is also a fusible link on the wire off of the horn relay buss that goes to the interior of the car.

These fusible links are shown though on the second picture of yours.

Just pay attention to your wire gauges and like they are showing a 14 gauge fusible link on the 10 gauge wire, further down the circuit where the wire changes to 12 gauge, then a 16 gauge fusible link is in place to protect that wire.

If later like you adding brake lights, this may be a 16 gauge wired circuit to where then closest to where you are getting power from, let's say the 12 gauge wire that where it is getting power from is protected by a 16 gauge fusible link then for the 16 gauge circuit put in maybe a 10A fuse.

Basically:

Battery positive---14 gauge fusible link--10 gauge wire----Horn Buss----16 gauge fusible link---12 gauge wire-----10A Fuse--16 gauge wire----brake lights

Every reduction to a smaller gauge wire requires a smaller protection device.

Jim
 

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Discussion Starter · #11 ·
Basically, yes this is what is needed.

Just be careful as the MAD stuff is a guide but lacks info in area's for the novice.

On the diagram with the 10 and 12 SI alternator, there is no protection on the circuits. One needs a fusible link, fuse, or properly sized breaker on the wire between the battery and the junction block near the battery.

On my 68, there is also a fusible link on the wire off of the horn relay buss that goes to the interior of the car.

These fusible links are shown though on the second picture of yours.

Just pay attention to your wire gauges and like they are showing a 14 gauge fusible link on the 10 gauge wire, further down the circuit where the wire changes to 12 gauge, then a 16 gauge fusible link is in place to protect that wire.

If later like you adding brake lights, this may be a 16 gauge wired circuit to where then closest to where you are getting power from, let's say the 12 gauge wire that where it is getting power from is protected by a 16 gauge fusible link then for the 16 gauge circuit put in maybe a 10A fuse.

Basically:

Battery positive---14 gauge fusible link--10 gauge wire----Horn Buss----16 gauge fusible link---12 gauge wire-----10A Fuse--16 gauge wire----brake lights

Every reduction to a smaller gauge wire requires a smaller protection device.

Jim
Awesome, Jim! Thank you for the info for sure!! I'll only be using this for a short jaunt so should be good to go. I have 10, 12, 14 & 16ga wire and I'll be placing fuses in-line for protection.
 
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