Fulltext TSBs

Technical Service Bulletins

TSB
03-21-25
  • WIRING – AFTERMARKET WIRING ALTERATIONS – SERVICE TIP
Publication Date: October 6, 2003

FORD:
1995-1997 F SUPER DUTY, F-150-350 SERIES

Article 97-7-9 is being republished in its entirety as part of a consolidated 7.3L diagnostic aid booklet.

ISSUE:

This TSB article will provide guidelines for connecting aftermarket auxiliary components to an underhood ignition switch-controlled power source in a way that will not alter the operation of existing Original Equipment Manufacturer (OEM) circuitry.

ACTION:

Complete aftermarket alterations that will protect against a current feedback loop or induced reverse voltage and provide circuit protection for Fuses 11 and 14. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

NOTE:AFTERMARKET ADD-ON INDUCTIVE LOAD DEVICES (ELECTRICAL MOTORS, ELECTRIC CLUTCHES, ELECTRIC PUMPS, ETC.) SHOULD NOT BE CONNECTED TO OEM CIRCUITRY OR FUSE PANELS. POWER FOR SUCH DEVICES SHOULD BE TAKEN DIRECTLY FROM THE BATTERY POWER TERMINAL. CONTROL OF THESE DEVICES SHOULD BE MADE THROUGH RELAYS. NO DIRECT CURRENT PATH SHOULD EXIST BETWEEN OEM WIRING AND AFTERMARKET LOAD FOR INSTRUMENT PANEL FUSES.

CAUTION:THE PROTECTION DEVICE RATING SHOULD NOT EXCEED THE CURRENT REQUIREMENTS FOR THE AFTERMARKET ADD-ON LOAD COMPONENTS AND SHOULD BE INSTALLED AS CLOSE TO THE POINT OF TAPPED POWER AS POSSIBLE. ALL WIRING MUST BE PROPERLY SIZED TO ITS CURRENT LOAD (REFER TO WIRE GAUGE CURRENT CAPACITY CHART LOCATED IN THE 1996 BODY BUILDERS LAYOUT BOOK (BBLB), PAGE C31 OR IN THE 1997 BBLB, PAGE C38).

NOTE:FOR ADDITIONAL WIRING INFORMATION, REFER TO THE ELECTRICAL WIRING SECTION IN THE 1996 BODY BUILDERS LAYOUT BOOK, PAGES C30 THROUGH C33 OR THE 1997 BODY BUILDERS LAYOUT BOOK, PAGES C37 THROUGH C41. FAILURES CAUSED BY AFTERMARKET ADD-ON EQUIPMENT ARE NOT COVERED UNDER WARRANTY.

  1. Choose Instrument Panel (IP) Fuse 11 or 14 for control box power source. Refer to Figure 1.
  2. Connect Circuit A1 to the selected fuse. The in-line fuse should utilize a sealed crimp connector.
  3. The control box should be diode protected.
  4. Circuit A1 grounding must be connected from R1 to the vehicle using a self-tapping screw.

    NOTE:DO NOT USE ANY EXISTING GROUND SCREWS FOR THE CIRCUIT A1 GROUND. ALL WIRING SHOULD MEET SAE SPECIFICATION J1128 SXL OR SAE SPECIFICATION J1128 GXL, OR EQUIVALENT.

  5. Attach Circuit A2 to the positive battery terminal.
  6. Connect Circuit A2 to a properly sized in-line fuse and normally open relay (R1).
  7. Connect R1 to item being powered and Diode 2 (D2). D2 must be wired to both sides of the powered item and should have no current flow during powered operation of the load.
  8. Ground the load as suggested by the manufacturer or supplier.

OTHER APPLICABLE ARTICLES:

NONE

SUPERSEDES:

97-7-9

WARRANTY STATUS:

Information Only




Figure 1 – Article 03-21-25


NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and equipment to do the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information that could assist in proper vehicle service. The procedures should not be performed by “do-it-yourselfers”. Do not assume that a condition described affects your car or truck. Contact a Ford, Lincoln, or Mercury dealership to determine whether the Bulletin applies to your vehicle.

Copyright 2003 Ford Motor Company