Vexing trailer light issue

[mdj61254]

All,<br />I hope someone can help me out with a problem I am having with the lights on my 2003 EZ Loader trailer and my 2003 Honda Odyssey minivan. When I installed my Hidden Hitch receiver I also acquired their wiring harness, which included the required converter. As you may be aware, on many Japanese vehicles one must utilize a converter to allow the connection of the 5-wire auto system to the 4-wire trailer system. I utilized this wiring harness a few times with U Haul trailers without any problems over a period of several months earlier this year. The first time I hooked up the boat trailer to the harness it worked fine, but the second time the right-side lights wouldn’t work. I took the trailer to the boat dealer and they hooked up a test light, which indicated that the signal for the right side (green wire) wasn’t coming through the converter. The dealer indicated that these converters frequently malfunction and suggested I get a new one. Consequently, I ordered a new wiring harness/converter through Honda and installed it last week. The first time I connected it to the boat it worked fine; the next time it blew the fuse to my taillights as I was driving and then none of the trailer lights would work. I disconnected the wiring harness from the trailer, replaced the fuse in the car, and checked the power coming out of the converter. I found that, again, the right side (green wire) was getting no signal; the rest of the wires looked OK. I guess this means the converter now needs to be replaced again; obviously I need to determine the cause of this problem so that I do not continuously have to buy wiring harnesses and tear the back of the van apart to gain access to its wiring. Have I been unlucky to buy two malfunctioning converters/harnesses or could an issue with the trailer wiring (on the right side?) be the culprit? Any suggestions on what might be going on here? Thanks, Mike

 

[Dunaruna]

Re: Vexing trailer light issue

Hi Mike, welcome to i-boats!!<br /><br />From what you are describing I would check to see if the honda's turn signal flasher unit (flasher can) is rated for trailering. Some flasher units are only good for the vehicle and not 'extra' lights. It's possible that it is overloading when you apply the turn signal and blowing the weakest link - the converter.<br /><br />Aldo

 

[Silvertip]

Re: Vexing trailer light issue

You say the system works fine the "first" time. Do you make it a habit of backing the trailer into the water with the lights connected? If so, disconnect them. Although the lights are somewhat better today than in the past, they still get wet and when cold water touches a hot brake/turn signal bulb, the filament can pop and often times lands on the tail light filament or ground, which can create some weird indications and may be the cause of the converter failures.

 

[Mark42]

Re: Vexing trailer light issue

I bet there is a short in the harness on the boat trailer. Because it worked fine with other trailers, I think the boat trailer is the culprit. Like upinsmoke wrote it could be water shorting it out. It could also just be a wire that is worn and shorting when it hits bumps, etc. <br /><br />An easy way to tell is to check the resistance on the suspect circuit then compare that reading to the left (good) side. If they are not the same, there is a problem. Water may or may not play a part. And I doubt you have had two bad converters.

 

[mdj61254]

Re: Vexing trailer light issue

Guys, thanks for your replies and suggestions. I have only placed the trailer in the water 3 times, and I have disconnected the lights before launching each time. It sounds like I need to do an inspection of the wiring and lights on the trailer, especially on the side that keeps burning out. I'll also need to get another converter, it seems! Can I check the wiring by hooking the lights up to a 12 volt battery so I don't risk damaging another converter? Thx, Mike

 

[mdj61254]

Re: Vexing trailer light issue

Aldo, the Honda flashers are supposedly robust enough to support trailers. The flasher (blinker) does work on the left side of the trailer, and on both sides on the van, so it appears I may have a trailer issue... Mike

 

[Silvertip]

Re: Vexing trailer light issue

MDJ -- approach this in a logical manner. Check the van first. If you have a test light or voltmeter, first turn on the headlights and then measure between the white and brown wire on the connector. If 12V is present, turn of the headlights. Turn on the four-way flashers. Measure between the white wire and each of the remaining two terminals (usually green & yellow). If the test light is flashing or meter is oscillating, all circuits are good. If not, the converter is bad (again) or its wiring is a problem. If the van checked out ok, you now know you have trailer issue. Do the simple stuff first. Remove the dual filament bulbs and check them with your ohm meter or a battery charger. Check socket connections and make sure the bulbs are correctly inserted. They are keyed to go in one way only, except the sockets are made so cheaply bulbs can be forced into the socket 180 degrees from where they should be. Check grounds at each light (that means clean and reattach them). Connections at each light assembly are also lacking in quality. Make sure those are ok.

 

[chuckz]

Re: Vexing trailer light issue

Mark42 has it right. Check for an overload blowing the right side of the converter.<br /><br />Small fuses installed in the trailer side of the converter may help save the next converter.

 

[fondafj]

Re: Vexing trailer light issue

Upinsmoke has some good advice...<br />As a suggestion to save on converters during you diagnostics... you can quickly install 3 inline waterproof fuse holders for $15 in the trailer harness with 2 amp fuses as a start (you may need to increase these based on your lights). If there is an intermittant short, it will only cost you a fuse and not a converter each time.

 

[mdj61254]

Re: Vexing trailer light issue

Thanks all for the great suggestions, I will be busy figuring the puzzle out this weekend!!! Mike

 

[T S N]

Re: Vexing trailer light issue

Those are solid state relays. One short and they are done.<br />Your best bet is to use fuses, this will protect you next time too.

 

[Silvertip]

Re: Vexing trailer light issue

Another way to test the trailer is to use a battery charger. Connect the negative lead from the charger to and unpainted bolt on the trailer frame. Insert a nail in the positive clip and touch the brown wire. Both tail lights and any side marker lights should light. Do the same for the left and right turn terminals. Now repeat the process with the negative lead connected to the wire wire in the connector. If everything worked before but not now, you have a ground wire problem.

 

[mdj61254]

Re: Vexing trailer light issue

Great ideas, all! I will be working with my trailer and battery charger this evening, I'll let you know what I find out...Mike

 

[mdj61254]

Re: Vexing trailer light issue

All, I checked the ground wire on the trailer, and it was barely hanging on by a few threads; I cleaned it off as well as where it conencts to the trailer and reattached it more securely, seems to have fixed the problem. Next step is to get another converter and some inline fuses to keep this problem from happening again. I did take a battery charger and check all the lights, that's definitely a great tip. Thanks, everyone, for your help!!!! Mike

 

[mdj61254]

Re: Vexing trailer light issue

Here's my latest (and final, I hope!) update on my trailer wiring issue. The reason for my tail light fuse blowing in my van was a short in the right side marker light on the trailer; easy to fix, not so easy to find (at least for me)! Mike

 

[chuckz]

Re: Vexing trailer light issue

See, Mark did have it right. I hope you installed some inline fuses so you didn't burn out another converter.

 

[mdj61254]

Re: Vexing trailer light issue

As a matter of fact I did, great tips from everybody on this!!!

 

[Mark42]

Re: Vexing trailer light issue

Chuck, thanks for the vote of confidence! <br /><br />mdj61254, when I read you thought the ground fixed the problem, I was skeptical. But kept my big mouth closed for fear of sounding negative (bad electrical pun, right?). <br /><br />Glad to see you found the source of the problem. A big hand to you for taking the time and trouble to track it down! And the piece of mind knowing it won't just blow for some unknown reason at the worst possable time.

 

[mdj61254]

Re: Vexing trailer light issue

Mark, you hit the nail on the head with this one, I'm now a believer in checking for shorts on trailers with strange lighting problems, thanks for all your advice...Mike

 

[mdj61254]

Re: Vexing trailer light issue

Ahhh, the saga continues! I experienced more problems with my lights last weekend, decided to take my time and work front to back and do some troubleshooting. My trailer has a tongue that pivots to save storage space, I took a good look inside the frame and the tongue had "pinched" both wires going to the right side of the trailer, no wonder I was having problems! I will splice new wire with waterproof connections and place a piece of plastic conduit on the wires in this area to hopefully protect them from the tongue frame as it pivots back and forth. This area is a good place to check if you have this type of trailer set up with light problems! Mike