help me fix my lights

[BrwBier]

I have a tail light problem that makes no sense. I hope I can explain it so it understandable. I have led tail lights from super bright. When tested with a battery at the connector everything is OK. When hooked to my 93 GMC jimmy everything is OK. When hooked to my 98 chevy venture the tail lights work OK, the turn lights work OK, the stop lights work OK, untill I have the lights on, then the turn lights don't flash, untill I step on the brake, then all is OK. The converter box on the venture was just replaced, grounded on the same lug as the other grounds for the van. The trailer lights are not grounded to the frame, all are on a dedicated ground wire. The connector on the van tests just fine with a plug in tester and with a test light. I hope this makes some sense to someone because it dosn't to me. I know in my mind that it can't work this way but it dose.
Thanks in advance to anyone who can explain why this is happening.
Brwbier

[Dale M.]

Converter boxes are crap... Even some NEW out of the box work poorly at best.... Suggest you try some other way to get tow vechicle wired. Check to see if there is a FACTORY harness available that does not use converter box.

Dale

[asianflava]

Yup, I agree it's the box. The filaments and wiring are obviously fine, especially since it worked on the other vehicle.

[BrwBier]

I had the same results with the box I replaced so that is not the answer. I did everything right just so I would not have a problem, that is why it is so confusing.

[JFJR55]

I install converters daily in my job. I use the "POWERED " converters to get away from what you are talking about. The only difference is the powered converter has a wire running from the battery. When a turn single, running lights or break lights are on it pulls power from the battery and not off the light wires on the car. You still splice wires to the car light wires. Cars & trucks with seperate break light and turn single are called 3 wire systems. A trailer is a 2 wire system, so a converter is needed.

[BrwBier]

Do you have a brand name I could look for? I guess that sounds like a reasonable answer. Nothing else makes any sense, like I said,I checked everything I would normally check on a car and everything checked out OK but it still would not work on the van.
Thanks
Brwbier

[bobhenry]

Before you do another damn thing grab your jumper cables and ground from vehicle to trailer. Bet ya 5 bucks it's a bad ground. I have hooked up 1000's of U-haul trailers and they will do the stupidest things with a bad ground. Thats why every light and 12 volt outlet should have a hard wired dedicated ground as far as I'm concerned.

[BrwBier]

As I said in my orignal question, everything has a dedicated ground. Nothing is grounded to the trailer frame and the car ground is attached to the factory ground lug inside the rear of the van. After 25 years of being a dealer tech I know that mutiple electrical problems are more times than not caused by a grounding problem. That is why I did everything to avoid that. All lights have a dedicated ground, all splices are soldered and heat shrink covered. The only thing I haven't done yet is to ohm meter the wires. I don't expect to find anything but I need to satisfy myself.
Brwbier

[bobhenry]

OOP"S I'M BAD ! My apologies I should read before I type,

[BrwBier]

That's OK, this is just such a frustrating problem. I just need to get it right.

[Arne]

led's do not draw much current. anything that depends and is designed on a regular bulb, like a flasher or converter box could have problems because of low current draw.

I put a signal light flasher on the 3rd brake light on my van (flasher was mounted in the top wind deflector at rear of van).. it would not work as the draw from the small bulb was not high enough.. I went to a heavy duty flasher (which I think has a tiny motor in it) and it worked fine.

[BrwBier]

I thought of the flasher also and replaced that, but thanks anyway.

[BrwBier]

All is well now. The powered converter was what fixed the problem. Thanks JFJR55. I am now happy with my trailer again.
Brwbier