Hacked up wiring help needed!! - Team Camaro Tech
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post #1 of 7 (permalink) Old Oct 4th, 09, 03:58 PM Thread Starter
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Hacked up wiring help needed!!

My 68 has really bad wiring thats really been hacked. It was running when i got it but i have moved/changed so many wires and im now so confused as to what is what. I question if it was even right to begin with so want to make sure i understand it all before i hook the battery back up.. I have a factory wiring diagram but it isnt helping me much.

Couple of areas of concern.

1) They have modified it to use a single wire alt. There is a heavy wiring going to the alt from the harness, i have not touched that. They have the original heavy red wire going to the 1wire alt, they have a sm green,white and darkblue with the heavy red that are all not being used. Over at the voltage regulator plug (no regulator) the only wire that has anything on it was a heavy red wire that goes to the battery direct. Is this correct? Hot all the time. Why would this be needed if there is no reg there? As far as i can tell this goes to the junction block originally which is the same place the alt/bat + go. Maybe there is more upstream that gets power from this spot too??

2) There is a connector coming from the firewall that contains in it. Wiper wires, washer wires, a woven whitish looking wire which i assume is switched 12v (orig coil +) as it is wired to my msd sm red. There is also a thick purple wire. more on this wire in a bit.

3) They have wired this to use a push button starter switch rather then the key. You turn the key on then push a momentary button on the dash which activates the starter. One wire on this switch is hooked to the starters large lug where the battery is also hooked. The 2nd wire on this switch is hooked to where my msd heavy red (constant power) and that thick purple wire from #2 is hooked to.. This does not seem right....
Nothing is hooked to the small starter solenoid terminals. Is it possible they are not using a solenoid and using this push button instead?? The wires to the pushbutton are rather heavy gage. Again this doesnt seem right.

So how do you guys think this should be wired up to be correct?? What is supposed to go to that heavy purple wire i mention above? Is that supposed to get constant 12v battery or is that supposed to just get energized when cranking the starter??

Was just looking inside the car. Most of the wires from the original ignition switch go to a 12pin (not all full) connector that isnt plugged into anything! Where does this usually plug in, i dont see its mate anywhere under the dash.

Last edited by jeffs68camaro; Oct 4th, 09 at 05:32 PM.
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post #2 of 7 (permalink) Old Oct 4th, 09, 05:57 PM
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Re: Hacked up wiring help needed!!

Jeff I am wiring my 68 using a complete harness from American Autowire. I have a similiar question. I used the heavy red wire from the battery terminal on my starter solenoid to the single pole on the alternator. Then I used the white and dark blue wires on the adaptor plug to go to the voltage regulator. There is also a heavy red wire from the junction block on 1 of the pins on the voiltage regulator. This is according to my shop manual wiring diagram. The question I have is I used a brown wire from the firewall connetion that goes into the fuse block on the inside of the car that then looks like it goes to the alt light and plugged that in to the last open space on the voltage reg. My Americam Autowire does not show the voltage reg. at all. I am also wirde into a MSD 6 and the matching MSD dist. Is this right anyone?

This harness also does away with the horn relay altogether. It comes from the firewall harness directly to the horns. Am I missing something here?
JeffsSS.....Yes my name is Jeff also lol
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post #3 of 7 (permalink) Old Oct 4th, 09, 06:19 PM Thread Starter
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Re: Hacked up wiring help needed!!

nice. 2 jeff's and 2 hacked up 68s!

I think the main thing i need to know is
1) What needs to go to that purple wire in the harness with the wipers..12v cranking or 12v always. Im guessing always based on what i have.
2) If i have no reg why did the previous owner jumper 12v to the thick red on the reg harness? Is this needed for something?? Maybe this is how the thick red on the horn relay gets its power too?
3) How should the starter be wired up correctly with the push button?
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post #4 of 7 (permalink) Old Oct 4th, 09, 07:01 PM Thread Starter
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Re: Hacked up wiring help needed!!

The more i think about this, there MUST have been something wired to the small S terminal on the starter solenoid. No way it could start otherwise, right? So i guess the one switch wire went to the MSD, Battery, Purple Harness wire,Starter. Then the other Switch wire went to the small solenoid terminal. Make sense?
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post #5 of 7 (permalink) Old Oct 4th, 09, 09:46 PM
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Re: Hacked up wiring help needed!!

Have a look at Mad Electricrical.
I redid my 68 Camaro using Mark Hamiltons diagrams and kits.
Mark is very knowledgeable and helpful.
The article above shows the original way the 68 was wired and how Mark updates everything.
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post #6 of 7 (permalink) Old Oct 4th, 09, 10:42 PM
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Re: Hacked up wiring help needed!!

Ditto what Paul said. You will see it on the MAD electrical site if you look around but 1-wire alternators are not good. Get a 10 or 12si if you want to use an internal regulator alternator or go back to the stock alternator and regulator. They have 3 wires, the large red one is power output, a voltage sensing wire for the regulator and the wire to turn on the regulator which also is used for the warning light in the dash. I suspect the fusible links have been removed as well so protect your car and make sure you have those or fuses on all major power circuits.

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post #7 of 7 (permalink) Old Oct 4th, 09, 11:19 PM Thread Starter
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Re: Hacked up wiring help needed!!

uggh that just confused me even more! So basically it says that even if i figure out how my car was wired, it is all wrong anyway!

Interesting reading, I have run many hotrods for years with 1 wire alternators with just a single wire to the battery +.. even modern EFI cars. Never had a problem that i knew of, but I guess i did?

Good call on the fuses. I think your right, many have been removed by the previous owner. The main thing im trying to fix are all his connections. 2-3 wires twisted and taped together with no crimp or solder connection.. horrible!

I think my goal is to get the connections fixed and get it all working as it was and then considor upgrades to the system such as the 3wire alt, etc..

The car is fairly stripped down, no heat/ac. msd ignition wired direct to battery. So main harness is basically just lights/horn/gauges.

One curious thing is they wired the 1 wire alt into the heavy red on the original harness. I have always wired them direct to the battery on cars i have wired.

Last edited by jeffs68camaro; Oct 5th, 09 at 12:06 AM.
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