'01 trailer connector wiring
 

Last night I started to install the trailer connector & harness for my GN in the bed of my '01 CTD. Located a spot I was happy with and cut a 2" hole in the inner bed wall for the new 7-wire connector. My 100' :rolleyes: spool of 7-conductor trailer cable showed up yesterday so I was set to run the cable and splice it in. I found a place that was accessible and acceptable to me to splice into the wiring harness, but I ran out of light and didn't get the tie-in done. I decided to tie into the trucks harness on the frame rail well before the stock trailer connector on the receiver hitch for two reasons:

1. Didn't want to run the extra length of cable to "backtrack" to my new connection point.
2. The factory trailer connector steps the trailer tow relay (used to power the trailer running lights) wire, the trailer brake signal wire, and the fused B+ wire down from 12 to 14 gauge.

I am a little :confused: about one circuit in the trucks wiring harness though. There are 9 conductors in the harness at the point I want to tie in at:

1. BR/RD - 16ga - right turn signal
2. VT/BK - 18ga - back-up lamp feed
3. RD/OR - 12ga - fused B(+)
4. BK/OR - 12ga - trailer tow relay output (running lights for trailer)
5. LB - 12ga - trailer brakes signal
6. BK - 12ga - ground
7. DG/RD - 16ga - left turn signal
8. BK/YL - 18ga - park lamp relay output (running lights for truck)
9. LG/TN - 18ga - ?????

I know what to do with 1-7 and 8 is not needed for the trailer connector but I'm not sure what 9 is. As best as I can tell, it is tied back to the turn signal/multi-function switch and is run to each of the turn signal lamps. Maybe the feed for the hazards? I need to do a little poking around and probing the wires with a test light to see if I even need to concern myself with this wire while hooking up my trailer connector.

Anyone have any insight?

Also, instead of hooking into the 12 gauge fused battery wire, I'm thinking about pulling a new 10 gauge conductor from power distribution block (fused, of course) back to the trailer connector tie-in. Also thought about pulling a 10 gauge ground from the connecter tie-in all the way up to the battery to ensure a GOOD ground for the trailer.

I guess nobody has any idea....:confused:

Mechanos I have a 01 FSM I can take pics of the wiring harness diagram this weekend...

Thanks... but not necessary. I have the FSM as well. It's just not real clear and the way they break the diagram up to fit the pages and label the splice points, etc. further clouds the issue. I studied it at length and flipped from page to page and was still not able to unravel a clear-cut answer. Hence my post.....

I would say no... Just hook up the 7. it's only a 7-pin connector.

I got my spool of trailer cable last Tuesday.... it's nice stuff. 4 - 14 gauge, 1 - 12 gauge and 2 - 10 gauge conductors. I was pretty surprised at how flexible it is... I thought it would be stiffer than it is. I haven't rewired the gooseneck yet, but I finally got a chance to splice into the trucks harness and run some cable up to a new outlet in the bed for my GN.

Spliced into the running lights (feed from trailer tow relay), left & right turn signals, back-up lights and trailer brake signal wires from the truck's harness right behind the fuel tank. I chose not to splice into the 12 gauge ground and 12 gauge fused (+) wires in the harness. I plan to run a 10 gauge wire from the power distribution center through a fuse back to the new harness for the connector to supply power to the trailer. I'll also run a 10 gauge ground from the battery back to the connector harness to ensure the trailer has a good ground. I haven't decided yet, but I may run the 10 gauge power wire through a relay that is activated by the ignition switch..... I need to think about just what I will be powering with it and just how I will want to use it.

I never did find out what the mystery wire (#9 from above) was for... by probing the wires with a test light, I determined that I didn't need it.

I had the same problem when I first wired up my GN as well. I didn't use it and everything works fine. Be sure you solder all the connections. I didn't the first time and had a terrible time with bad connections from time to time.