Trailer Wiring Recommendation for a 2005 Dodge Ram

Updated 09/29/2014 | Published 09/28/2014

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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$56.73

Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional

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$159.88

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

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$121.17

Miro-Flex LED Clearance or Side Marker Light w/ Reflector - Submersible - 9 Diodes - Amber Lens

(770)

$9.94

Hook Probe Circuit Tester

(60)

$12.41

Optronics LED Trailer Light - Brake, Tail, Turn - Submersible - Oval - Red

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$12.40

Question:

Dear E-trailer, I have a 2005 Dodge Ram 3500 and a 20foot PJ 14,000 lb car hauler trailer. The first part of my questions is in regards to part # C55504, a trailer dealership installed a 7-pole socket part # PK12702, I do not know if this truck came with a tow package wiring harness, what I see under the truck is four wires that appear to come from the front of the truck in the factory loom not from the tail lights, Black #16 Ga. - ground Brown # 18 Ga. - running lights Green # 18 Ga. - Right turn - Brake Yellow # 18 Ga. Left turn - Brake. From what I am reading about part #C55504 is that this kit is needed to change a three wire Dodge system into a two wire system to match the trailer wiring, which my trailer has a two wire system. Is this part C55504 made for Dodge trucks that do not have these four wires running from the front of the vehicle and is this part C55504 to be used by pulling off of the factory taillights? because I see no plugs as indicated in the description. if true, does this mean that the four wires described above from my Dodge have already been changed to a two wire system from the factory control panel? Second part - My 20foot PJ car hauler trailer has 13 running lights, part #MCL50AB and 2 - 6 1/2 oval stop - turn - tail part # STL72RB, these lights are six years old so they might not have the same amp ratting as newer ones or the models that you sell, and there are no marking on the lights to indicate the amps but that gives you an idea what where talking about. The wire size on this trailer feeding these lights is # 14 Ga. When I was stripping the Dodge OEM wires mentioned above, the Green, Yellow, and Brown that I believe are #18 or #20 gauge, the insulation was melted to the copper strands and was very hard to strip and left pieces of insulation on the strands that had to be removed with a razor knife and sandpaper, from the above information provided does this melted insulation indicate that the wire is overloaded for the lights on this trailer or is this normal for insulation on small gauge wire? If the green, Yellow and Brown wires are underrated and melting the insulation why wouldnt a fuse of blown? if this is a problem how would I up size these wires and what size wire would be required for the lights mentioned above? would I run bigger wires from where these are coming from or is there a aftermarket harness that plugs into a panel up front then which I would run bigger wires to the back? I ordered #10 gauge Blue primary for my brake controller and my 12 volt power for my brake-away battery are of adequate size. Thanks in advance Sincerely

asked by: Mark K

Helpful Expert Reply:

Since you have what sounds like a factory 4-way (or wiring) installed on your 2005 Dodge Ram you would not need to worry about circuits being installed or combined and needing the correct adapter. The harness you have for your 4-way wiring is already combined and ready to go. You can use a circuit tester like part # PTW2993 to confirm that the wires you have found are correct.

If you have a 4-way on your vehicle all you would need is the part # ETBC7 to install a 7-way and brake controller. If you do not have a 4-way or 4-way wiring you would also need the part # C55504. This will install behind the taillights.

If the 4 wires you found are for a 4-way instead of the # C55504 would want the # 18252.

For a brake controller I would recommend the Prodigy P2 Brake Controller part # 90885. This is our best selling brake controller because of how well it works and how easy it is to setup.

Since LEDs draw such a miniscule amount of amperage I would be very surprised if you are overdrawing your circuits. For example the # MCL50AB you have on your trailer draws .187 amps at 12 volts. That's almost nothing. The # STL72RB only draw .243 at 12 volts.

If the wires really did melt I would assume the problem was a short on the circuit. Somewhere on that circuit there may be some exposed wire that is touching the trailer frame causing it to short out. Larger gauge wire wouldn't help. The thin gauge you have now should work just fine.

I attached an FAQ on trailer wiring for you to check out as well.