2003 Wiring Diagrams


I have had very little luck finding wiring diagrams online (or for sale) for a 2003 3.8L. The best I can do Is find a pinout for the 2001 pinout and compare it to the engine harness (which I am building a wiring diagram for).

The newest edition of the Haynes Manual from 94-04 is basically useless post 1998.

Does anyone have the 03-04 version?


Does anyone know where I can find an engine bay wiring diagram?

Fundamentally if someone is willing to do some searching, I need to know where they Red/Yellow wire runs to. (I know it is a power wire, for the IMRC and EGR Valve Control Solenoid, and I am fairly certain it is a hot on run wire. Even if you just know which fuse it runs to, I could make do.

Thanks in advance.
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hmm... I don't like the idea of buying a membership for content that should be accessible in a book, endlessly, for the same price or less.
If I have another use for it I will look into it, but I don't think I am not going to pay $30USD just to get some info on a wire.

Thank you for the suggestion though, it's good to know what resources are available.

6 Shooter

Well-Known Member
send a private message of your email address and I'll send you the wiring diagram for the 104 pin PCM wiring harness with wire colors.


I found what seems to be a FSM (Factory Service Manual) or WM (Workshop Manual) for the 2003 3.8L V6 & 4.6L V8 (GT) mustangs on allcarmanuals.com.

It has some wiring diagrams. Now I feel like having spent the time making my own wiring diagrams was a bit of a waste. ...I guess at least mine has pictures of the connectors & pins and follows the layout of the harness?