Mixing Lights and Grounding questions

[Don't Panic!]

I've got a 1987 trailer (19ft boat, single axle painted steel trailer with surge drums) that is in good condition, but it needs some work. In this project, the wiring is getting a re-do. The existing wiring uses trailer chassis grounds for all the lights, and all connections are the blue scotch locks, not sealed at all. It works at the moment, but I've got one bad tail light (old sealed incandescent full of water, and no way to drain it or replace the bulb) and one broken marker light. The harness at the front end is also just a bit short for my truck, so I'm currently using a short extension which I'd like to eliminate.

I'm going to start from scratch and bring a new harness from front to back, with direct grounds to all the lights.

I have two questions:
1. When running direct grounds to each light fixture, do I still ground the harness to the trailer also? If so, where? Just once at the tongue?

2. Can I mix LED and incandescents? There are 7 marker lights, 6 of which work fine. Can I replace the tail/brake lights, and one of the markers with LED's but keep the working markers as is (but rewired)? Not a big deal, but that's like a tank of gas difference in cost if I don't have to replace all the markers.

Thanks for the info, just trying to keep this trailer on the road for a few more years.

 

[alldodge]

1. When running direct grounds to each light fixture, do I still ground the harness to the trailer also? If so, where? Just once at the tongue?

I would run a ground to trailer just because it won't hurt anything and may help

2. Can I mix LED and incandescents? There are 7 marker lights, 6 of which work fine. Can I replace the tail/brake lights, and one of the markers with LED's but keep the working markers as is (but rewired)? Not a big deal, but that's like a tank of gas difference in cost if I don't have to replace all the markers.

Yes, this is no issue. Just note the LED's do have a + and - side

 

[jhande]

1. I wouldn't bother grounding the lights to the trailer frame. I would just run the grounds through the ground wire at the plug.
2. Mixing lights are fine. Just keep in mind that the LED might be brighter.

 

[Don't Panic!]

Sounds good, I'll replace both brake/turn signals with LED but keep the existing markers that still work. Probably will keep the ground connection at the tongue since it's already there, but remove the rest.

This poor boat/trailer has lead a nice sheltered life of fresh water and garages (mostly garages) for the last 35 years. I'm now dunking it in salt weekly. Things that were fine are suddenly not (like scotch locks) Something about boats in the harbor though, right?

 

[jhande]

I meant to add...
For wire connections I would use the ones that heat shrink or at least heat shrink tubes.

 

[Don't Panic!]

My plan is to use simple non-insulated butt splice connectors with adhesive shrink tube over it. I've had better luck with that than the connectors with built on heat shrink.