Wiring Prep circuits' fuse location? - Diesel Forum

artherd · 07-12-2006, 05:51 AM

Dumb question, can't find this in the search, in google, or any other forum.

I belive I have found the so called "Wiring Prep" wires, they are sealed with dippable rubber and are floating in the engine bay next to the brake master cyl, where the ECM harness punches through.

But, which wires are which, and to which fuses are they associated? In short, I need a wiring diagram for these babies. It is rather emberasing that I haven't been able to find one in searches, have mercy! [img]/ubbthreads/images/graemlins/smile.gif[/img] PS: see sig for truck production date, it is an early 99 if it matters.

crzybowhntr · 07-12-2006, 10:52 AM

Try asking Grampy Jim.

Here is a post he made.

Black05 · 07-12-2006, 11:43 AM

Check the wires with a circuit tester -- you will find they are not energized. They are merely pass through wires that you can hook to and then find the other end under the driver's dash to hook up to the appropriate power supply.

artherd · 07-12-2006, 05:40 PM

OH... not that exciting then :P These guys must be wrong: "A four-circuit wiring prep in the instrument panel eases the job of mounting aftermarket controls in the cab. The wiring prep is sealed against water leaks from the engine compartment and is on its own fuse-protected circuit. " http://www.truckworld.com/Truck-Test.../f-series.html

Sigh.

GrampyJim · 07-13-2006, 02:24 AM

It appears that the "wiring prep" your article is referring to is the connector for the trailer brake controller, located to the right of the steering column, under the dash. Re-read the entire paragraph carefully.

The four wires you see coming out of the harness near the brake booster terminate under the dash (somewhere behind the central junction box) to the left of the steering column.