Trailer Lights Gurus--Got a Question.

[jaxs]

Yes, but that is because it runs off the running light wire. The 12V line primary purpose is to charge the capacitors to power the trailers brake actuators.

I wasn't aware of those capacitors. Will you please tell us where they are located on this '03 Dodge Dakota and one other vehicle of any make or model? If not on truck,tell us location on a make and preferably model trailer. I'm pretty sure they will be listed in parts list for truck or trailer. Always god to keep spares.

 

[WranglerX]

My 57 sure doesn't, not even a switch for hazards.

Who leaves their vehicle to go get a flat repaired??? I put on the spare and drive the flat to the shop.

Lets be realistic not many of us are doing wiring on a 1957 vehicle....

 

[jaxs]

My 57 sure doesn't, not even a switch for hazards.

Who leaves their vehicle to go get a flat repaired??? I put on the spare and drive the flat to the shop.

Owners of 2014 Dodge Grand Caravans with hide-a-way 2nd and 3rd row seats to name some that do. I'm sure there's others,like those who forgot spare,spare is flat or never had a spare since buying truck. But this shouldn't prevent you nameing a vehicle so let's hear it.

 

[Midniteoyl]

Yes both trailer lights are connected to white leads on trailer harness. The white lead on pickup harness is attached to pickup frame.

Test results are in:
Fuse slot "C" in engine compartment labeled "Trailer Tow Connector" is an inactive slot so no fuse.
Fuse slot "T" in engine compartment labeled "Trailer Tow Connector" was empty so I installed a fuse.
Now getting "blinking power" at trailer connector between white and green and white and yellow pins with ignition switch on but LIGHT SWITCH OFF in the pickup. Hazards working also. No power to brown on connector which is as it should be with pickup lights off.

Haven't connected trailer yet but will do and expect all lights to be working as they should. Been working on this for almost 10 hours now with about 90 minutes out for lunch and nap. Going to have a beer now if you all don't mind.

Edit: Thanks to herm0016 in post #29 for arousing my suspicion that a fuse was lacking even though is wasn't necessarily the fuse for 12 VDC power.

The weird thing is that I've been pulling this trailer around for about 20 years now and have checked the old trailer lights on occasion, even last week, and found them to be working without the pickup lights on.

I suspect that the new lights, being LED, may have had something to do with it since the fuse was missing. Just weird.

Thanks to all for weighing in on the thread.

Not sure just how adding a fuse for a feature the truck doesnt have made it work, but I'm glad you finally got it working

 

[WranglerX]

Yes, but that is because it runs off the running light wire. The 12V line primary purpose is to charge the capacitors to power the trailers brake actuators.

Please explain where said capacitor are found..... The trailer brakes on my trailer (with 7 pin connector) are controlled by after market controller (below dash) which is actuated off brake pedal switch....

The other constant positive 12 volt lead (on 7 pin connector) to rear is to either charge the battery for trailer breakway brake circuit or maybe power lamps inside of a enclosed trailer ....

 

[CausticUrbanCoast]

Why would the trailer brake actuators be on the vehicle? What good would that do after the trailer leaves the hitch and tears off the wiring?

The controller is on the vehicle and a rudimentary receiver on the trailer to apply the proper pressure to the brake actuators whether they be electric, hydraulic, or pneumatic.

 

[CausticUrbanCoast]

Btw 1966 hazards were optional, 1967/1968+ they were required by USA DOT.

 

[Midniteoyl]

Why would the trailer brake actuators be on the vehicle? What good would that do after the trailer leaves the hitch and tears off the wiring?

The controller is on the vehicle and a rudimentary receiver on the trailer to apply the proper pressure to the brake actuators whether they be electric, hydraulic, or pneumatic.

Are you trolling us...?

 

[npalen]

I give up! After installing the fuse and finding the connections worked on the trailer connector as described in post #38 above with the pickup lights off, I hooked the trailer up and now find that none of the trailer light functions are working with or without the fuse and with or without the pickup lights on! Go figure.

Edit: So I go out now and did some more troubleshooting and find that the fuse I plugged in was in an inactive port BUT now I have all light functions working on the trailer connector again even with lights OFF.

I'm thinking there is a bad and intermittent connection somewhere in the pickup aftermarket trailer harness. Will pull the harness in the morning and clean all the connections as someone suggested above.

 

[Midniteoyl]

Take a break and start again tomorrow. Start from the top and make sure the trailer lights still work, then double check that adapter ground where it connects to your truck. Personally, still betting on the tralier light adapter kit you installed years ago being faulty, or at least dirty connections on it.

Take that break. You're going in circles at this point.