We forgot to ask some details on the travel trailer. What kind of electrical connector is on the trailer? I mentioned you should check that the trailer has brakes but neglected how to tell.
Besides crawling under the trailer to check an easier way to do this is look at the connector that connects to your truck. The minimum connector on a trailer is a flat four pin connector. This means the trailer does not have electrical brakes. If the connector is 6 or 7 pin, then the chances are high that the extra pins are for a "brake" and the other is for a "hot" wire. If you have seven pins then this might include for "reverse".
The brake lead is usually blue and would be the one to connect for the brake controller to apply the trailer brakes when using a brake controller in your vehicle.
The hot wire is usually white and is a 12v lead for charging the trailer's battery systems.
If there is a reverse lead I've seen these in orange or some other color and this provides the power for the backup lights of the trailer and when the truck is in reverse (and the backup lights engaged), then the trailer's backup lights will be turned on, too. This is a nice feature but not all trailer's have it. I use a 7 pin connector on the truck and while my trailer also has a 7 pin connector, the reverse is not used.
In the case of the flat bed trailer you might only have a 4 wire connector providing turn signals, running lights, brake lights and the return ground. Since theses trailers are typically designed to weigh NO more than 3,000 lbs and an auxiliary brake system is not needed. This means the tow vehicle does ALL the braking for both it and the trailer.
Finally, if a flat bed or rental trailer (like most U-Hauls, etc.) will still have a 4 wire connector and still must carry more weight (>3,000 lbs). What is done in this case since many vehicles with a tow option still only have a 4 pin (not 6 or 7 pin) connector, these trailers will have what call an inertia brake system. These are mounted on the tongue with a device that senses movement (especially nosedive) and detects when the tow vehicle is slowing down, then automatically applies the trailer brakes accordingly.
Whatever the case, know what type of braking system is on your trailer:
- none (for lightweight trailers)
- inertia brakes - mounted on the trailer's tongue and operates independent of the tow vehicle.
or
- electrical brakes and requires corresponding wiring from the tow vehicle for applying the brakes by measuring the amount of pressure on the brake pedal to apply for adequate trailer braking and for also activating the trailer's brake lights.
Notice I am only covering my experiences with utility and recreational trailers. I am not covering the much more advanced hydraulic or air systems used with brakes. I haven't had to tow anything that large.
I hope this helps.