I'm replacing the lights on the trailer of my 92 Ranger and have a couple of questions and concerns to make sure I'll do it correctly.  First I've bought LED rear lights to install but still have the normal bulb lights for running lights, is this O.K?  Second I'm concerned about getting those running lights working.  Will a squeeze connector be the best option for connecting a wire from the tail wire to the running lights or is there a better option?  Any help is greatly appreciated.  Thanks!

The best option is to solder connections, then coat them with shrink tubing, or the "liquid latex" that can be found in most hardware stores in the electrical department.  Auto parts places should also carry it.

The crimp on connectors will work if done properly.  Be sure to seal them with shrink wrap tubing or the liquid latex.

While you're doing that, inspect all wiring where it passes through the trailer frame for chaffing or missing rubber grommets.

You can find grommets at most hardware stores.  The local ACE hardware store carries an assortment of many sizes. 

Thank You Sir. Will a connector like this work?  Also, will it be a problem if I'm using the LED rear lights and normal bulb running lights?

I prefer the inline type of connectors where the wires butt to each other.  More streamlined than the side by each type.  Can use smaller shrink tubing on the inline connector.

Regarding the LEDs.   They draw less current than the filament type of bulb.  Shouldn't pose any problem that I know of.

What Rhino said.  I butt-solder most all of my connections and cover them with heat-shrink wrap.  As for combining LED and filament bulbs, no problem.

.....and you will really like the LED tail lights. I installed them in the spring and they are MUCH brighter than the old bulb lights were.

Thanks guys!  Well I'm going to install them tomorrow and I'm really hoping I get it right the first time. The reason I'm using the crimp connector like the one I posted a pic of is because I'm connecting the running lights from the side of the tail wire not the end.  I haven't been able to see how it would be possible other than that yet.  The way the old lights were installed was was direct wire to wire contact covered with heat shrink tubing, no crimping piece at all.  The tail wire was just exposed near the running lights and another short wire was connected right to it.  I'm not sure how that was done or how I would do it so that is why I chose the connector I pictured.  I am going to try and cover all the connections I use with heat shrink tubing so they are protected.  Thanks again, I'll post how it went soon.

Keep in mind, with two wires side by side, the shrink tubing will not make a watertight seal, it will bridge the gap between the wires, but not fill it. It allows for water intrusion.

Get a small container of the liquid latex. See below. You should be able to find the same sealer at a hardware store or home improvement center.

http://www.etrailer.com/Accessories-and-Parts/Spectro/SWC50122.html

Keep in mind, with two wires side by side, the shrink tubing will not make a watertight seal, it will bridge the gap between the wires, but not fill it. It allows for water intrusion.

Get a small container of the liquid latex. See below. You should be able to find the same sealer at a hardware store or home improvement center.

http://www.etrailer.com/Accessories-and-Parts/Spectro/SWC50122.html

I did pick some up after your suggestion, that's what I'll use on those connectors.  Heading out to install them soon, had to see if there was any posts before I left, glad I did.  Thanks.

New light installation was successful!  When I went to connect after they were installed I realized my front ground wire wasn't long enough so I quickly crimped some more wire to it and started it up.  Left tail on, right tail not on, but both turn signals work.???  Realized I had my right tail wire connected to the right turn wire and not the tail wire.  Fixed this and started it again.  This time all lights came on (with the exception of one side marker) that I think may have a blown bulb and all signals worked.  Brushed liquid latex on all my connections and wrapped it up for the day.  Nice to get something important done while it's still winter.  Thanks for all the tips guys!

What Rhino said. I butt-solder most all of my connections and cover them with heat-shrink wrap. As for combining LED and filament bulbs, no problem.

He said Butt Solder......... 

Sorry. I had to do it.......