Rebuilding 5 X 8 Utility Trailer and Wiring Trailer To Have 7-Way Connector

Question:

I have a 2012 Chevy Silverado Work Truck that has a 7 way factory installed at the back of the truck. I also have a 5 x 8 utility trailer that needs some upgrading done. Specifically, I need to replace the tires 4.80 x 12 and I want to pack the wheel bearings as this has never been done before. The lights are old and are incandescent. I want to upgrade to LED lighting. My plan is to start with a 7 way with a junction box. The 7 way will plug into my truck and bring power to the junction box. From the junction box I will install new wiring to the running, stop and turn lights on the passenger side and the driver side of the trailer. I know how to do this as I have done my research. When I am finished with this lighting upgrade I will be able to plug the 7 way on the trailer coming from the junction box into the 7 way at the back of the truck and I am good to go. My question to you is if I or someone else were to pull this trailer with a vehicle that only has a 4-pin flat on their vehicle, how do I adapt my 7 way on the trailer to a 4-pin trailer side flat that will match up with the 4-pin flat on the other vehicle? Is there an adapter available to use? Another solution is to come out of the junction box with a 4 wire cable white, yellow, green, brown that has a 4-pin trailer side flat connector and bring this up to the front of the trailer. I would then have my 7 way cable/connector and also a 4 wire flat connector at the front of the trailer. This would allow the trailer to be pulled and the trailer lighting would receive power either from the 7 way or the 4-pin flat depending on what the tow vehicle is equipped with. Do you see any potential issues with this solution? Please advise me.

asked by: Michael D

Expert Reply:

First here are some parts I am going to recommend for fixing up your trailer. The Taskmaster 4.80R12 Radial Trailer Tire # TT48012C is a great option since it has a radial versus bias construction. This will give you better highway characteristics and increased tread life. For the wiring the Wiring Kit # HS381-9000 will give you a 7-way and junction box along with connectors for inside the box so you are not trying to find all the right sizes. The 4-way Trailer Harness # A25W2GWB is a great option for wiring in some LED Lights # M844 and # M844L as it has a full length ground wire which helps eliminate the common trailer ground issues.

As far as your question about the trailer connectors, you will be best to create your own adapter using the 7-way Female # PK12-707E and 4-way Male # HM48114 connector. This will eliminate the chances of damage to the additional connector either from dragging on the ground our shorting out since the exposed male plugs would see power when the 7-way is connected and could easily case a short even with a storage cap in place.

If you need help with replacing your bearings I would need to know what sizes you currently have as if they have never been changed it may be a good idea to get all the bearings, races and grease seals replaced with new if you are already taking things apart to put all fresh Grease # L11390 in.