How to Set Up an RV Tow Bar System

Heading down south for the winter? Wish we could say we weren’t just a little bit envious. But you've earned the right to enjoy the warm weather, escaping the constant bite of harsh northern winters and just leaving the rest of us here to deal with the snow and ice.

Are you thinking about taking a commuter vehicle with you, but aren’t quite sure how to get that vehicle down with you? Well, you’ve come to the right place! What you’re going to need is a dinghy towable setup and we’ve got all of your starter information just below!

 There are three major manufacturers of towbar setups for your motorhome:  Blue Ox, Roadmaster, and Demco.  RV Part Shop carries all three of these top suppliers in our complete catalog of RV parts and accessories.

The towing setup typically consists of six components: 

Tow Bars

This is the actual link force between your RV and the car or truck you want to tow.  A tow bar is usually classified by weight capacity (the allowable weight of the towed vehicle) and where it is mounted (on the motorhome or on the towed vehicle.  Most modern tow bars are motorhome mounted because that's the best place to store the tow bar when you're not towing.  You don't really want to have this big honking hunk of metal on the front of your car when you're tooling around town, it's not necessary.

Tow bars, in addition to the weight capacity, will have different options depending on the level of the tow bar you purchase.  Since in its essence the tow bar consists of two arms connecting your hitch on the motorhome to two anchor points on the front of the towed vehicle, these options generally relate to making it easy to either connect or disconnect the two vehicles from each other.  Thee features include things like collapsible arms, levers to release those arms (helpful when you want to disconnect the car from the motorhome on uneven ground when there can be some binding of the arms), and a stiff fulcrum point to sort of hold the bar up when you're connecting to the towed vehicle.

Other available features include cable and safety chain channels and built-in brackets to use when storing the towbar on the motorhome.

Base Plate

On all motorhome mounted tow bars, you will need a base plate to be installed at the front of your towed vehicle, below the grill, and connected to the frame.  These base plates are custom to the towed vehicle and serve to present a common connecting point to the tow bar itself.  Most base plates will accept a removable crossbar that your tow bar will connect to, providing an additional layer of strength and stability.   The connectors on the ends of the tow bar arm connect to this crossbar. 

Installing a base plate is not a difficult job in most cases if you have any kind of mechanical background.  The manufacturers provide good detailed instructions on how to complete a baseplate installation efficiently and safely.

Inserts are available to clip into your base plate receptacles as well to keep moisture and dirt out of them when you are disconnected from the motorhome.

Safety Chains and Cable

Just like when you are towing a trailer, all jurisdictions require you to install safety chains or cables between the motorhome and the crossbar on your towed vehicle.  This is so that there is less likelihood of the car/truck disconnecting fully from the motorhome if your tow bar fails.  Make sure you have a cable/chain of sufficient weight capacity for the vehicle you are towing.  We especially like the ones that are coiled into a collapsible "spring" configuration that extends when you hook up the two vehicles.  These are less likely to be dragging on the ground than a straight cable or chain.

In addition to the main safety cables from motorhome to "toad", make sure you don't forget the short (usually about 1') safety cables required in a tow bar set up to secure the crossbar to the baseplate. 

Supplemental Braking

In most jurisdictions, any towed vehicle over a certain weight is required to have its own separate braking system.  Almost all passenger vehicles are over this weight in all jurisdictions.  Motorhome/Towed Vehicle setups use the car or truck's own braking system to provide for this regulatory requirement.  Legacy braking system tied into the motorhome's hydraulic or air braking systems and simply applied the same pressure into the towed vehicle braking system.  The downsides were the compromise of the motorhome braking system and the fact that this method did not allow for the portability of the braking system to a second towed vehicle.

A modern braking system generally consists of a device that sits in the vicinity of the car or truck's brake pedal and attaches to it, applied an equivalent amount of braking pressure to this pedal that it senses the motorhome is applying to its brakes.   Blue Ox's Patriot and Roadmaster's Even Brake are joined by the Brake Buddy line as the most popular braking systems of this kind.  These sit in the driver's footwell against the driver's seat and apply pressure to an arm connected to the brake pedal.  They then connect to a 12-volt outlet in the vehicle for power.

Manufacturer SMI as well as Roadmaster (with their Invisibrake system), offers a range of small box style of brake controllers that mounts under the driver's seat.  These offer the convenience of being permanently connected and not having to find a place to store the braking unit when you're not towing.  The downside is that they are not as portable as the footwell-mounted systems. 

All of these braking systems will feature a breakaway system that will apply full braking power if it is sensed that the motorhome and towed vehicle have disconnected.  For this, you will need to install a breakaway switch on the front of the vehicle as well.

Towed Vehicle Electrical

You will need to configure an electrical setup to power the tail, brake, and turn signal lights on your towed vehicle from your motorhome.  There are two ways of doing this:

1. Utilize the car or truck's own rear lamps, powered by current from the motorhome.  To do this you will have to install diodes between the separate feeds (car and motorhome current) to prevent the 12 volts from the motorhome from feeding back into the car's electrical system.  You may also need a 2-way to 3-way converter device if your motorhome has the brake and turn signals on the same "filament" (a 2-way system) and the towed vehicle has separate brake and turn lamps (a 3-way system.)  

2. Install a separate lamp socket in the taillight housing on each side of the rear of the towed vehicle and feed the motorhome 12-volt signal to these lamps.  This has gotten much easier to do in recent years with the introduction of LED lighting kits with much smaller lamps.  The biggest thing to ensure when you are doing this is to properly seal the socket so that no water can get into the housing.

In both these scenarios, you will have to route at least a four-conductor wiring harness from the back of the motorhome to the rear of the towed car or truck.

A final note on electrical, some towed vehicles require you to remove or disconnect a fuse so you don't deplete the battery and/or rack up towed miles as miles driven on your car's odometer.  There are fuse switches available to do this disconnect, as well as battery charging solutions that keep the towed vehicle's battery charging from the motorhome when you are flat towing.

RV Part Shop carries all the items you need to install a towed vehicle setup in our RV parts and accessories catalog.  If you're having trouble finding a certain item, just contact us for advice and direction.