More tail light/brake light problems

[greasywheats]

Howdy-
Hooking up my trailer wiring. Have 7-pin connector on tow vehicle ('97 Nissan Pathfinder) and trailer. Checked tow vehicle connector with tester and found all in working order. However, the trailer connector/wiring harness is not color-coded according to the colors noted on www.etrailer.com and in diagrams on this site. I tested the various wires on the trailer harness though and identified the turn light wires and running lights and ground, etc...

My problem is this...All running lights (including tailights) work on the trailer when I turn on the parking (running) lights in the vehicle. Leaving the running lights on, I then tested both Rt and LT blinkers....both operated correctly. However, when I then depressed the brake and then tested RT/ LT blinkers, the left (drivers side) blinker operated, but the right blinker did not. It just seemed to have the tailight filament lit and the brake filament lit.

I also noted that when I disenegaged the brake and tested the blinkers again (they both worked again) that all the side marker lights and the non-blinking tail light dimmed noticeably in time with the blinking tailight.

I did not ground to frame but ran a dedicated ground wire to a bus bar.

Any ideas where to troubleshoot here. I am sure it is something stupid that I overlooked...I am just too tired to see it myself. I have read about the tail light converter, but don't know if I need that here as the left tail light & blinker/brake light seem to work.

Thanks!

[Leon]

What kind of voltages are you reading?

[Miriam C.]

Try this. Run a ground wire directly from your tail light to your frame.

http://tnttt.com/viewtopic.php?t=18309

Good luck!

[vipercairo]

Best idea... grounds can cause more problems if continuity is not made. A dedicated ground to the trailer frame is essential.

[Miriam C.]

Btw---where are your lights on the trailer. Got a picture?

[bobhenry]

Since you have ran your ground directly to the buss bar run a dedicated ground from each light fixture to the same grounding bar and you will never have another light problem. With many of our light fixtures mounted on wood surfaces of our tears a dedicated ground system is the best thing you can do when running your electrics. I have ac and dc dedicated grounds. The gfi system on the ac side has been tested and works ( accidently shorted out a porch light during wiring).

[Mike C.]

bobhenry,


Our AC wiring is on a GFI and we have never had a problem with it. It's what I do, AC wiring. But DC with all the grounding makes me crazy.

We worked on the trailer for 8-9 hours yesterday and finally figured out it was a grounding problem, after wiring, unwiring multiple times.

Anyway, think it will work now.

[Sonetpro]

It sounds like you don't have a good ground to the tow vehicle. I would check the ground on the trailer connector on the TV. A lot of times the ground is going to a screw to the frame of the TV. Rust of that screw would prevent good continuity. On my CJ-7 that is notorious for grounding problems I have a ground from the battery neg to the trailer connector.

[greasywheats]

Leon- I'll have to check my voltage readings and get back to you.

Others- regarding the ground...I hooked all tail light/ market light grounds to the bus bar and then connected the bus bar to the trailer connecter using 12 ga. copper. So the frame is not being used as a ground path.

Gonna play around a little more this morning...will report back.

[greasywheats]

Ok- played with my wiring for a few more hours this morning and here's what I did...

Disconnected the tail light ground wires from the ground bus bar and direct wired them to the ground wire on the trailer wiring harness (without wiring in the grounds for the side marker/running lights). This takes the 4 side marker/running lights out of the equation. It also takes the bus bar out of the equation.

Checked all connections for tightness (currently taped as i have not wanted to solder until I figure this out). Rechecked tail/brake/turn functions and got the same condition (Rt turn light does not blink when brake and parking lights are on, but does blink when the brake is not engaged).

Next...unplugged both tail light units and switched them (right for left). Since I was not having any issues with the left unit (blinker operated brightly with both parking lights and brake engaged), I figured that I could check that it was not the actual right taillight unit that was defective. Made the switch and the problem remained isolated to right side. So the unit is operating correctly...it must be the trailer or vehicle wiring operating the RT unit.

Before I left, I checked my readings at the vehicle connector and found the voltage on the RT turn signal to be between 10.2-11.0 (approx.) when the turn signal is blinking. However, my reading on the LT turn signal shows voltage in the 6.0 to mid-7 range. I was 95% certain that i was checking the right blades (RT vs. LT), but will have to recheck as this doesn't make sense. It would make sense if I have LT & RT readings reversed. If I have the readings reversed, it would lead me to believe that there is something wrong with the wiring harness that connects to the vehicle connector.

I feel like I am getting closer, but this is really testing my patience. Sorry for the long-winded report, but even if it doesn't help anyone else, it will help me to keep track of what I have done so far.

I'll keep ya'll posted!

[madjack]

greasy...do you have seperate brake and turn signal lights on the TV, if so, you will need a logic circuit(available from etrailer and other similar places) to make them work properly on the trailer...from your description of the problem, this sounds like the cure.......
madjack

[greasywheats]

Mad-
Yes they are seperate on the TV (couldn't figure out what TV was for ). I thought that i needed that at first as well, but then when the turn signals and brake worked on the left side, I was stumped. Any idea why the one would seem to work ok and not the other?


I'm still concerned about the voltage readings I was getting on the RT vs. LT turn signal blades at the TV connector...

[madjack]

...don't trust the 7pin to 4pin adapter to be manufacured correctly...take the adapter off and use the ohm side of the meter to check resistance thru the adapter...don't have any idea why one side would work and the other not but electrcity and logic don't always go hand in hand...if you have seperate turn and brake lights on the tow vehicle(TV) you WILL need the logic adapter, they also sell a logic adapter that takes power for the trailer lights directly from the battery...
madjack

[bobhenry]

http://autoaccessories-4-less.stores.yahoo.net/motaco.html

His madness is correct you have a 3 wire system and need a converter you are currently backfeeding form God knows where to God knows where. This is not good when combined with onboard computers. There are several tee conectors custom designed for your pathfinder. If your fed up go to a company u-haul center and tell them you are going to rent a trailer next week and want your hook up checked, Its supposed to be a no charge courtesy ( except parts ) Should take 6 to 10 minutes.

[greasywheats]

..take the adapter off and use the ohm side of the meter to check resistance thru the adapter...
madjack

Madjack- Lost me here - do you mean unplug the wiring harness from the "Adapter 4 pole to 7 pole to 4 pole" and test the voltage at the end of the wiring harness? If so, and if the voltages show normal (10-11V ?) at the end of the wiring harness, but drop at the adapter blade, you think the adapter then needs to be replaced?

As for the converter... i can use this one if I want a direct connection to the battery (http://www.etrailer.com/pc-VWH~18146.htm), or the one Bobhenry listed (The Hoppy) if i don't need the battery-direct connection. Since I am running LED side marker lights (12 LEDs each) and the stop/turn is 2.1 amps, I probably don't need to go direct to the battery - is my thinking correct here?

Thanks as well, bobhenry!

Thanks for your input!