Voltage reg. question.

[prayers1 153]

I thought this picture might be helpful to others with similiar projects regarding the differences between 69 and 70 Ignition Switch Wire Ends.

 

 

I know that the 69 has a black connector, does anyone know what color the 70 is?

 

Here's a picture of the one bought on eBay, but yet to arrive. I think I see a black connector. I hope it's the right one.

 

 

Important question?

 

I don't know why this problem happened to the prior owner, but judging form all of the burnt wires close to the Ignition Switch. Should I also replace that switch?

[prayers1 153]

Here's a pretty good explanation I got regarding the two differences.

 

"The 69

had a dash mounted ignition switch that the harness plugged directly into, the 70 with the steering

column ignition switch has a different connector (rectangular shaped). Also in 69, the starter solenoid and charging wiring were part of the under hood harness. In 70 they are part of the under dash harness. And easiest of all - the 69 harness has a part number on the tag that starts with C9 - the 70 harness part number starts with D0."

[LoneWolf2U 136]

:thumbdown:... To the PO.

Looks like he did a short cut for the 1 wire alt and cooked the harness.

Yes it may be your best bet to replace the switch now.

Those burnt wires could have also leaded to frying the internal contact points of the ign switch causing you more frustration later once you have everything replaced.

 

Not completely sure but from that pic you posted of harness it looks like a 70 ign switch plug is in the center of the pile,

The long flat one.

Edited May 8, 2011 by Mach1Rider

[prayers1 153]

Just got the eBay wire harness. FoMoCo Purple tag on harness states S/X-F, C9ZB-14401 AE. Has the 69 Ign. Switch plug. From what I gathered on the web, it's a NO Tach, No AC, Std harness just what I need. Not bad for $62.90.

 

If anyone has access to the FoMo books, please confirm what the above code mandates.

 

I gonna wipe down the harness and get it ready to install. I did notice due to age some metal contacts look oxidized (greenish) How best to lightly clean then.

[prayers1 153]

After cleaning the harness up, checking the wire patterns and more surfing on the web, I'm pretty sure I got the right harness.

 

Before I destory this new one, I want to make sure I do the right procedure of converting the Ign. to Coil to 12 volts.

 

I'm looking at the color diagram above. I see that the PINK Res. wire goes from IGN © to the engine harness, therefore I have to replace the same with a heavier gauge wire to get 12 volts instaead of 7.5v.

 

The PINK wire is hard wired into the ING. Switch. Do I cut the PINK wire a few inches from the switch, then join the new wire? Is having a few inches of the PINK wire gonna drop my volts?

 

Do have to Join the NEW wire to the green/red (904). That wire is also hard wired into © Ign. Switch. OR just leave (904) alone.

 

I take the new wire from the Ign Switch ©, cut the Brown wire (262) and join the 2 together, then extend the new wire to the Coil.

Now what do I do with the other end of the brown wire (262) that goes to the fuse panel?

[buening 63]

What ignition components are you planning on using? This will determine if you need to bypass the resistor wire. An inch or so of wire won't add enough resistance to drop the voltage much, if you do have to bypass it.

[LoneWolf2U 136]

To keep it simple, just replace the pink resistor wire only!

Clip it as close as possiable to switch and other end.

Do not touch brown wire.

 

Tip: When you open up the harness to expose the resistor wire, Feel it. The section of resistence wire will feel fatter.

There is usually strand wire sections at each end of the resistence wire used for termination.

This is where you want to cut for splicing in your new wire.

[buening 63]

....but if he plans on using, for example a MSD Blaster II coil then if he bypasses the pink resistor wire he will need to add in the ballast resistor to bring the voltage back down to where it was with the pink resistor wire. This is why I ask what type of coil he plans on using. If it is the newer style that actually needs 12V, then by all means bypass it. He mentions the PO had the Accel Supercoil, but he needs to be sure that is the type of coil he wants to use.

[LoneWolf2U 136]

See post #43, he states the coil he is going to use requires 12v.

[buening 63]

Ahhh, I see. Well nevermind LOL

[danno 128]

If a 12 volt coil is to be used, fine. But be absolutely sure it is a 12 volt coil. If it is not, everthing could burn up all over again. If you take a coil designed to operate at a lower voltage and connect it to 12 volts, the car will start and run fine. Run fine, though, until the coil overheats and shorts out. A shorted coil will then start burning wires because the only fuse to it is a fusable link by the solenoid, and that was probably removed by the PO. Maybe that is how the whole burned wire process started?

 

So be 100% sure you have a coil designed to be connected to 12 volts, with no ballast resistor or resistor wire.

[prayers1 153]

Please tell me if any of you agree with my plan.

 

Yes, it is a 12 volt coil, Mallory Promaster e-coil, Mallory Unilite Distributor.

 

The plan is to cut the PINK wire 2-3" from the Ignition Switch and 2-3" from the engine wire harness grommet before going into the fire wall, then connect a 14 gauge wire with a fuse between the two.

 

If I splice the new wire as described above, that will still leave 7" of the PINK wire that will go through the firewall and up to the black connector for the engine harness. Is the 7" OK! OR will I still get some voltage drop?

 

Or, should I cut the brown and PINK wire before the firewall, splice the brown wire to the new wire, run the new wire through the fire wall all the way up to the coil, this way I eliminate the 7" of PINK wire.

 

Below is a picture of my PINK Res. wire from the Ign. Switch up to the firewall grommet.

 

Also, can someone tell me what the light blue/red stripe wire wrapped in a circle is. Its next to the engine harness connector.

 

[buening 63]

Is the firewall grommet molded to the wires? I'd cut 1" from the ignition connector and run one length wire to the coil. Adding that many splices introduces more areas for it to fail and cause fires.

[prayers1 153]

So, your thinking not to mess with the brown wire, but allow it to run to the coil by itself and to run the new wire seperatley to the coil. I can either drill a hole in the firewall, use a grommet and run directly to the coil or I can cut open the engine wire harness grommet on the firewall and run the new wire through that.

 

You mentioned not to have too many splices. How does everyone feel about a fuse between the new wire for safe assurance.

 

Would a fuse give any resistance

[buening 63]

My thought was to cut the pink resistor wire by the firewall grommet and pull the wire from the other side to remove it from the grommet. If your new wire won't fit through the hole in the grommet that the pink wire occupied, then find the drill bit size for the hole and step up one bit size. Thread your new wire through that hole and tape it into the harness under the hood to where your coil will be mounted. I'd leave extra wire and not put a terminal on until you are 100% sure where you are mounting the coil.

 

I'm not familiar with the brown wire (other than what is for the starter solenoid), so I'll have to look at a wiring diagram.

[buening 63]

After looking at the diagram for the 69, what does everyone think about having him use the Green/Red wire (now use for coil +) that is at the same ignition switch post as the pink wire which runs to the "S" post of the Voltage Regulator? That wire he could use for the coil + as it should have a full 12V, and assuming that wires isn't hacked to death he could put his coil in the general vicinity of the regulator and not have to splice any wire or cut that pink wire. Just a thought.

[prayers1 153]

After reading your post, I felt funny about reaming a bigger hole in the multi-firewall grommet in fear of nicking another wire, therefore I went to see how much movement I have at the PINK wire at the molded firewall wire grommet. I found that I could easily pull that wire through the grommet, therefore I can pull the new wire through the same hole and still have a safe route through the firewall.

 

There is still one thought remaining. After the firewall molded grommet, the brown wire and PINK wire share the same terminal on the 3 wire engine harness.

 

I would like to do the following:

Cut the PINK wire flush off at the engine harness terminal, fill in that cut off with silicone, then plug in the orignal coil wire at the 3 wire harness and feed the coil.

Next, then run the new wire from the Ign. Switch right to the coil.

 

To answer your question regarding that brown wire, I found the following explaination:

 

The brown wire is coming from the rear small terminal on the starter motor relay. It powers the coil to give you spark while you are cranking the engine. When the car starts and is running, you let off the key and the car is still running being powered off the pink wire that runs from the © terminal ignition switch.

 

Here's a picture of the brown & PINK wire leaving the firewall grommet, becoming one at the engine harness plug in.

 

[LoneWolf2U 136]

Clip the pink wire between that black mark and eng harness plug.

Pull the wire out of the firewall grommet and slide new wire in its place and splice it.

Remove pink wires end from ign switch plug and attach new wires end to connector and replace it into the plug. Done!

[danno 128]

You are correct about the brown wire. At the connector under the hood, the brown and pink wire come together. The pink wire has resistance and goes to the ignition switch to supply voltage to the coil when the car is running normal. The brown wire goes to the solenoid and has 12 volts on it when the car is trying to start. So what these 2 wires do is supply a full 12 volts to the coild when the car is starting, and the voltage is reduced when the car is running.

 

The brown wire starts from where it meets up with the pink, at that connector. From there is goes through the firewall to the underdash harness to the fuseblock. It does not go to a fuse, but that is where it goes back through the firewall and connects to the primary under hood harness. The wire then goes through the under hood harness to the solenoid.

 

You are on the right track with your changes, I just thought of explaining things a bit more.

[prayers1 153]

Thank you for clearing things up, I am bit green when it comes to electrical work, but I do see progress on my learning due to this site. I've taken things into my own hands instead of farming it out, there is a sense of pride and self reward that follows even the smallest of challenges.

 

Yes, I do believe I am on the right track, I now know what wire goes where to conclude this project, but I'm still a little unsure about the points of splicing.

 

I would like to pull out the barrell terminal in the Ign. Switch, remove all of the PINK wire, then place the new wire and the green/red wires back in the barrel connector, then place the barrel connector back into the Ing. Switch. I don't see any way that I can get the barrel connector out of that hard plastic Ign. Switch. If I don't get it out, I have no other choice but to leave approx. 1 1/2" of the PINK wire sticking out for splicing. I've already cut that end of the PINK wire and can see how thin the wire is compared to the new 14 ga wire.

 

Now as for the other end, I have the same scenairo. The PINK wire and brown wire come together and are connected by a barrel connector, then molded into the 3 wire engine harness. On that thought, I would cut the PINK wire flush with the 3 wire terminal and only use the brown wire from that and run it right to the coil. I would then take the new wire form the Ign. Switch and run it directly to the coil as well.

 

My thinking is this, I believe if any of the PINK wire is used, there is a chance for a voltage drop or possible over heating of that PINK wire.

If I can take out as much of the PINK wire that I can, the less splicing along the way and less chance of a future problem.

 

Maybe because of my naive electrical experience, I may be a little too cautious. I don't know! What do you think?????????????????????????

[prayers1 153]

Well, I took the plunge and did what I thought was best.

I was able to pull the barrel terminal © out of the ingition switch plug, removed all of the resistor wire and installed the 14ga and green/red wires, slip the barrel in and tape the ends to prevent it from pulling out.

 

At the engine 3 wire plug, I slit the molded part on the side of the coil wire, I was able to slide out the barrel connector and remove all of the resistor wire. I then ran the 14ga through the firewall grommet and install the same with the brown wire on the barrel connector, I then slid the connector back into the 3 wire plug and wrap it with electrical tape.

 

I think it came out pretty good, it's not show quality, but the wires will look close to stock if anything.

 

Next, I'll have to install the dash & headlamp harness and then the drivetrain, then I'll be back in business.

 

I couldn't of achieved any of these repairs if it wasn't for the GREAT people on the 69Stang Forum.

 

Thank You to all!

John

Edited May 12, 2011 by prayers1