trailer wiring installation issues

[91BroncoBoy]

New to the forum and not sure how it works so here's my issue. I have a 91 full size bronco and she appears to have a "factory installed"(?) trailer connector. It has both a 7-pole AND a 4-pole spliced into the 7-pole connector. I purchased a Pollak part #11-998 to replace the rusted original one. However, when i try to trace the wires to connect them properly, i cannot locate the black (power) wire on the truck wiring harness. Now I'm not even sure if the new plug will work! ugh!!

 

[Seabronc]

Welcome to the Zone!  I don't have a wiring diagram for a 91, but I suspect the color code has not changed over the years.  Check to see if there is a heavy yellow wire,(probably a number 10).  If so, check it for 12V, that is provded the fuse for that line is in and good.

Good luck,

>-

 

[miesk5]

yo 91,

another WELCOME!

Wiring Colors TSB 89-14-17 for 90 Bronco & F Series
Source: by FORD via miesk5 at Ford Bronco Zone Forums

http://broncozone.com/topic/19970-trailer-wiring/?gopid=105291

TSB 89-14-17 Trailer Wiring Colors
Publication Date: JULY 14, 1989

LIGHT TRUCK: 1990 BRONCO, F-150, F-250, F-350

ISSUE: Trailer tow wire harness color codes have been revised to be compatible with SAE color code standards. When hooking up a vehicle to a trailer that has been wired according to the SAE standard, the wire color/circuits will match.

ACTION: Refer to the following Circuit Color Code Chart for the correct color/circuit usage.

CIRCUIT COLOR CODE CHART
CIRCUIT FUNCTION - OLD COLOR* - SAE COLOR*
Trailer LH Turn/Stop - LG/O - Y
Trailer RH Turn/Stop - O/LB - DG
Trailer Brake Lamp From Controller - R/LG - R/LG
Trailer Electric Brakes Solenoid - BL/BR - DB
Trailer Back Up - BK/PK - R/Y
Trailer Ground - W - W
Trailer Running/Tail - W/R - BR/W
Trailer Power (Battery Charge) - Y - O
Trailer Brake Control Feed - R - R

Color Key - Color Abbreviations
BL-Blue
BK-Black
BR-Brown
DB-Dark Blue
DG-Dark Green
LB-Light Blue
LG-Light Green
O-Orange
P-Pink
R-Red
W-White
Y-Yellow     

I'll try to find a wiring diagram for you; or you can try local library and see it they have Free access to Chilton on-line or  ARRC Repair Manual there or at home via www. My library has All Data on-line for free but in-library use only; All Data uses the Ford docs