1968 Mustang - Headlights come on with ignition to "On" position

[ESolorzano]

Hey everyone

Background - I recently replaced my engine wiring harness because it was looking a little tired. After the installation I have what appears to be a number of issues.

1. Burned out the Starter Relay - Fixed this issue, starting the vehicle is not an issue any more. Incorrect wire connected to the ignition switch.
2. Headlights come on w/ ignition switched to "On" position
3. And a couple of other issues that I'll post later.

This issue seems to be related to the ignition switch as well, Just not sure at this moment as to how the ignition is providing power to the headlights when the ignition key is in the "On" position. Note that the headlight switch in set to the "Off" position.

 

[Mcmahst]

If you could post year and photos of what you replaced, that would aid in figuring out what wire is crossed. Having a correct year wiring diagram is essential. Steve

 

[ESolorzano]

Thanks for the post Steve.

Steve if you need better pictures or even want to talk real time, send me an email at [email protected] and I send you my phone number.

I think I have may have wired the ignition pigtail incorrectly. If you could help verify the position of each wire that would be great.

Connection Under Dash Harness Ignition Switch Comments
1. Yellow Wire Yellow Wire Thicker wire than the rest, not sure of the exact gauge.
2. Violet " Violet " Colors match but I don't know where they go
3. Black " Green w/Red Stripe & Pink Wire Performed a test, see below
4. Red w/Blue Stripe Red w/Blue Stripe The connection goes to the Start Relay "S" Post and is working as expected.
5. Black w/Green Stripe Black w/Yellow Stripe Thicker wire than the rest, not sure of the exact gauge.


Test - I wanted to verify that the Pink wire was correctly connected, so I did the following. The car starts before the test.
* Disconnected the battery, cut the pink wire which I believe goes to the coil. Result the car would not start.
* Reconnected the Pink wire to the Black wire (under dash) and the car again starts.
* Result, I think this wire is correctly connected even though the colors do not match.

Other Notes - The car starts as expected but when you turn the key to the "Off" position the engine does not turn off. Again, I think my ignition is incorrectly wired.

 

[ESolorzano]

Steve

My table above got too hard to read. I'm hoping that this attachment is something you can read.

Thanks
Eddie

 

[Mcmahst]

Look at this link. It’s a set of diagrams, etc for your 68 Mustang. Use this to verify that each wire is where it belongs. This site is quite good for this purpose:

1968 Mustang Wiring Diagrams and Vacuum Schematics

On this page is a list of areas covered by the 1968 Mustang wiring and vacuum diagrams; scroll down the page to see the diagram image gallery’s for both. Find more 1968 Mustang Assembly Manua…

averagejoerestoration.com

 

[GOvert]

Red/green or green/red should be (key on) power to the coil.
here is a link on another Mustang forum where this is being discussed for a 1968.
1968 mustang ignition switch wiring

 

[ESolorzano]

Look at this link. It’s a set of diagrams, etc for your 68 Mustang. Use this to verify that each wire is where it belongs. This site is quite good for this purpose:

1968 Mustang Wiring Diagrams and Vacuum Schematics

On this page is a list of areas covered by the 1968 Mustang wiring and vacuum diagrams; scroll down the page to see the diagram image gallery’s for both. Find more 1968 Mustang Assembly Manua…

averagejoerestoration.com

Thank you, I'll take a look.

Much appreciation
Eddie

 

[ESolorzano]

Red/green or green/red should be (key on) power to the coil.
here is a link on another Mustang forum where this is being discussed for a 1968.
1968 mustang ignition switch wiring

Thanks GOvert

I'll take a look, this is part of my problem. I dont have good documentation.

 

[Mcmahst]

The good news is, lots of documentation is available and it’s free!

 

[ESolorzano]

I have already solved one problem and found a blown fuse as well. I'll post more as I comb through the schematics.

Thanks for the reply
Eddie