Anyone know if there is a limited number of lights the factory trailer harness on the truck can tolerate?
I'm looking to add some extra running lights on my trailer, also want to put a couple of lights on each running board on the truck, they will be tied in with the trailer harness since it is not monitored by the BCM.

I did a search on this a few different ways and couldn't find anything.




SD Dually

 

I would think adding a few more wouldn't hurt the system. I have 11 lights total and have no issues

 

Running Lights on trailers pull such a small draw that they can be added with no problems for a while. A 42' trailer i haul bulls in has probably 15-20 running lights on each side and is just plugged right into the truck on a 7-way plug and no problems. Trailers with animals need to be WELL LIT so we try to keep all of the lights working and bright.

 

Another tip....Use LED Lights if your worried, they don't pull enough power to worry about
My 5'er has 12 of them...No worries here

 

I work at a hitch shop. Your fuse for your tail light on your trailer pack should be a 20amp. As long as you don't go over, you should be good... All else fails, like King-bRanch says, convert to LED. I have seen trailers with over 50 LED lights pulling about 7amps.

 

Thanks guys.

Figured up there will be 28 lights total on the trailer plug, (this includes the trailer's tail lights & the added lights on the truck's running boards.)

Only 4 of the running lights will be LED for now.


Any idea how many amps 28 lights will draw (4 of them will be LED) ?







SD Dually

 

if you're going to wire it that way it would be best if you fuse the trailer circuit with a 7-10 amp, that way you won't loose your trucks lighting if you experience a fault.
I would recommend using one of your upfitter switches and put your trailer lights on it's own dedicated circuit triggered by either your running light or ignition circuit.
Example; I ran two 20a circuits (on 10ga.) back to a housed relay triggered by my reverse lights to control two 55w. back up lights. The other is a 20a. future circuit for whatever.

 

Thanks guys.

When you say convert to LED, does that mean changing the lights out to LED or just change the bulbs to LED?




SD Dually

 

LED's will reduce draw either way. Just depends on what style lights you have to work with as far as if LED bulbs are available or if you need to replace the whole light. Just watch LED bulbs, as LED's tend to have a very narrow projection and depending on how the bulb sits the actual light through the lens may not be as good as intended. Full replacement with LED lights would be the best option IMO if you are going to do it.