Trailer braking, running lights, etc. & current load

[noseoil]

This is something I've been pondering and haven't been able to find yet. If there's a sticky, please point me at it, but here's the question. I have an '07 Nissan Frontier to use as a TV. Had a hitch installed with a 4 wire flat connector, which I may change over to a 7 pin once the trailer is finished. The function on the connector is correct and it works well. My question is about the loads on the existing harness and electronics in the truck. The trailer I found is from about 2000 and still has the original filament bulbs all around. I tested this when I first hooked it up and things work, but... the turn signals are over-loaded once the trailer is being towed. Since I'm working on it for now, the wiring isn't a big concern or problem, but once it's in use, things will change.

I'm going to install LED lighting as far as the running, turn signal & brake lights go for the final build. These are a much smaller load and should be much easier on the TV's harness than the old stuff which functionally doubles the current load. Since the truck already has incandescent bulbs, will the LED wiring on the trailer work better than the extra loads created now with the two sets of filament bulbs? Hoping the LED stuff will cure the balky turn signal flasher issue. I don't want to fry anything in the truck, so am I missing anything here by changing over to LED lighting from all of the exterior stuff? Is there a relay needed on some vehicles (specifically the Frontier) to accommodate the extra loads I should be looking into now? Thanks in advance for looking.

[M C Toyer]

I am sure some of the electrical experts will address the load and wiring specifics but the quick fix for the balky flasher is a heavy duty flasher which will be plugged in to replace your present flasher.

[twinight]

LED loads are 1/10 of incandescent loads.
I spliced into the light circuit of my highlander hybrid and the LED trailer lights did not affect the TV. My highlander already had LED tailights as well.
Easiest solution would be to replace the incandescent bulbs with LED drop-in units.

[bobhenry]

Humor me and conduct an experiment, it will take you about 60 seconds.

Drag out a set of jumper cables and clamp them on the tow vehicle frame and the trailer frame making sure you have a good bite. If the problem disappears simply install a hard wire ground from the trailer to the tow vehicle. 90% of lighting problems are caused by a poor ground.

[Dale M.]

Typically stop/turn element (filament) of 1157 type bulb is about 2 amps, the "dimmer" marker filament (element) is about , 0.50 amp... 1156 single filament bulb is same as bright filament of 1157, 2amp...

The typical LED stop/turn element is about 0.45 amp (.450ma)and the tail/marker portion is about 0.023 amp(.023ma) so if you were to replace stop/tail lamps in trailer and tow vehicle you would be well below the engineered specification and fusing of stop/tail lamp circuit of tow vehicle... Would not hurt to convert side markers in tow vehicle and trailer to LED also....

The actual numbers quoted here are real as measured by me when doing a conversion project on a street rod...

IF you are having flasher problems, you need heavy duty unit the can flash 2 to 8 incandescent bulbs to have it operate properly.... IF converting to LED, you need electronic flasher designed to work with LEDs as the LEDs do not draw enough current (amperage) for standard incandescent application flashers to operate properly...

Dale

[noseoil]

OK, thanks for the feedback folks.

This weekend I'll do the ground test first (thanks Bob), to see if it's just a grounding issue causing the problem. I'm going to my welder's place, so it should be simple enough to check once I hook it up again. If that doesn't work, I'll take a look at the flasher unit to see what's up with it. I was hoping for something simple on all of this, so until I do a test, it could just be an easy fix to sort it out. Thankfully I have plenty of time to look into it.

I know the flasher unit is load-dependent and will malfunction with the wrong current draw (single bulb goes out & blinking is rapid, etc.) so I'm hoping the LED will be OK once it's installed. Still wondering if other people have had similar things happen with turn signal circuit when hauling a small trailer & what their fix was. Will post back this weekend once I make the trip and let you know. Thanks, tim

[noseoil]

Strange, I'm looking at re-doing the ground wire on the trailer frame. I tried a jumper cable to the frame & truck, but no luck (thick paint?). The turn signals started working after I went to the car wash to clean the frame up, prior to a trip to the welder today. Once it dried out, the problem returned. I think it's looking for a ground, or I need to check the existing older wires. I will prevail!

[Dale M.]

Sounds like ground issues .... Take spray bottle of water and wet ball/hitch (lamp fixtures) and see if that improves condition... Any electrical connection has to be clean, bright, bare metal....

Dale

[Kharn]

Double check your fuse/relay box, my truck has one set of fuses for the truck's lights and a second set for the trailer's lights, with relays to activate the trailer's lights.

Also, check for electrical grounding from your trailer harness plug to each light socket on the trailer. Many trailers just have the ground (white IIRC) wire tied off to the nearest screw on the tongue and rely on the metal frame of the trailer to conduct. Paint, rust, etc, cause loss of ground. The easiest solution is to run a ground wire to each light fixture.

[noseoil]

I hate loose ends on things, so here's the answer to my question from this thread. I couldn't figure out the turn signal problem (intermittent when wet, etc.) and had repaired the ground circuit at the hitch, but without any luck. Yesterday I installed the new LED brake/turn signal lights. Had to drill new mounting holes, add holes for the wires & redo the old setup.

As was suggested in the above posts, it WAS a grounding issue! The previous owner had installed a new light & the ground was just barely making contact under the light assembly. That was why a good soaking would make things work, but in a dry condition (99% of the time here in Tucson) it wasn't working Here's the temporary fix, not too elegant, but functional. I scraped the frame to bare metal, used some #14 wire from an old power cord, stripped the insulation & took a full turn around the carriage bolt, added a washer& some conductive grease, then clamped it down to the frame. It works! As I said, ugly but functional and the new lights are working well now.



The new LED light module. I'm going to trim some metal so there is better visibility from behind and above. Still thinking about how much to take off, where & how.



Here's a view with the light brackets, license plate & ground wire in place.



Detail shot of the back of the bracket at the frame, new stainless bolts, old holes filled with silicone seal & the "temporary" wire loom in place. I soldered all connections, even though it isn't the final installation. No telling how long this will be in place at the rate I'm working on things. Could be for years still, but I hope not...

[Dale M.]

NO..NO... NO.... So many things wrong here....



Remove bolt, cut wires add proper crimp on connector(s) using a screw with flat washer and lock washer (not carriage bolt) and refasten after polishing frame add adding dielectric greaser....

Dale

[noseoil]

Dale, this is to have brake lights & turn signals while I'm working on the build, only! There will be clean ground wires run to each light for the build from a grounding buss. A completely new harness will be made and installed in conduit from the tongue box to the galley, to split things up and go to each corner. This setup is to get sheet materials only, have a plate plainly visible and be legal for driving. It is temporary!

[Dale M.]

Dale, this is to have brake lights & turn signals while I'm working on the build, only! There will be clean ground wires run to each light for the build from a grounding buss. A completely new harness will be made and installed in conduit from the tongue box to the galley, to split things up and go to each corner. This setup is to get sheet materials only, have a plate plainly visible and be legal for driving. It is temporary!

Oh..OK...

Dale

[tony.latham]

Humor me and conduct an experiment, it will take you about 60 seconds.

Drag out a set of jumper cables and clamp them on the tow vehicle frame and the trailer frame making sure you have a good bite. If the problem disappears simply install a hard wire ground from the trailer to the tow vehicle. 90% of lighting problems are caused by a poor ground.