A trailer that you use for hauling your ATV, boat, lawn care equipment or anything else heavy will suffer lots of wear and tear quickly and easily. Even though these trailers are meant to be durable and rugged, they will eventually have parts that wear down and outright break. While it's always good to have a mechanic double-check the repair work that needs to be done, you might note a few tips for troubleshooting a vehicle trailer first. This will tell you if there is a quick fix you can handle on your own, or what you might be facing by way of repairs.
1. Brakes aren't working
You don't want to hit the brakes of your vehicle and notice that the trailer is not stopping at the same time, so be sure you check this problem as soon as you notice it. The breakaway cable may be loose; this cable detaches the brakes when you want to unhook the trailer or move it manually, but it should be in a locked position when on the road. You can jack up the trailer and rotate a tire manually while someone else applies the brakes of your vehicle and note if the cable seems taut. If not, it needs to be reset, and the brakes should work. Otherwise, the brake lines that provide brake fluid may be blocked or crimped, and they may need replacing.
2. One wheel pulls or lags
As with your vehicle, a locked-up brake on one wheel can cause it to pull or lag. The brake may not be so engaged that the wheel doesn't rotate at all, but it can interfere with that wheel turning properly; it then pulls to that side or lags behind the other wheels. Air in the fluid lines can also mean an interrupted flow of fluid, so that the brake pads don't release when you let off the brake pedal, and the tire then drags.
3. Brake lights don't work
If the brake lights don't work, burned bulbs are the first thing to check. However, very often a trailer will get dust and debris built up along the connectors of the wires. This is where the trailer's wiring plugs into the vehicle itself so that the brake lights respond when you apply your vehicle's brakes. You can unplug these connectors and give them a light spray with an industrial lubricant such as WD-40 or another similar brand, and this may remove any dirt, dust, motor oil, and the like.