Voltage Drops at Clearance Lights on Aluminum Cattle Trailer with 25 Clearance Lights

Question:

Hi I have an aluminum cattle goose neck trailer. It has approx. 25 truck lite style 21inch clearance lights on it. I am seeing Voltage on that circuit at 8.7 volts. when lights are on. At the plug on the truck the voltage is 12.8 on this circuit with no trailer plugged in. Is this a normal with this many factory lights? I am hoping to put leds in over time to help this but it is costly. Do you think there is an issue? If so were to look? Thanks

asked by: Ryan

Helpful Expert Reply:

You have a lot of lights on your trailer drawing power from the running light circuit. As long as the lights are lighting up properly there is no reason worry and you can switch out LED lights a little at a time.

If the lights are dim then the combined power draw is likely too much for the tow package wiring on the tow vehicle to handle. Usually when this is the problem it will blow a fuse on the tow vehicle. You can check the wiring for each of the lights to make sure that they are all grounded to clean and corrosion free bare metal surfaces. You mentioned that the trailer is aluminum and aluminum does not make the best surface for a ground. I recommend attaching the grounds to the main trailer connector ground or to any steel surface that is available.

Switching over to LED lights is a great idea since there are so many clearance lights on the trailer and because LEDs draw such little power compared to incandescent lights. I have included a link to all of the LED clearance/side marker lights that we carry for you.

expert reply by: Michael H