How to Route Roadmaster Tow Bar Wiring Harness Part # RM-154 in a 2007 Saturn Ion

Question:

Is there an opening from the trunk of a 2007 Saturn Ion to run the flat 4 wire to the front, or do I have to make one. regards,

asked by: Clare I

Expert Reply:

The Roadmaster Tow Bar Wiring Harness Part # RM-154 requires that you locate holes through which you can pass the 4-pole RV connector wiring. It is usually possible to locate rubber grommets that already have wiring passing through them if you remove carpet and trim panels in the rear of the vehicle. The tail light wiring may also provide an access point; you can try removing the driver-side taillight assembly to see if there is a grommet you can use.

Once routed to the underside of the vehicle the wiring can be secured with the supplied wire ties to non-moving and non-heat-generating structures under the vehicle. Often it is possible to piggy-back onto other existing wiring. This process is far easier if you have access to a vehicle lift. You might want to refer to the linked article on trailer wiring; although this concerns a different type of wiring, the general ideas for routing wires are the same.

If you are unable to find existing grommets or pass-through holes as a last resort you might very carefully drill an access hole in the vehicle. It is important that before you do so you ensure that there are no important structures behind the place you are planning to drill, such as fuel system, electrical or hydraulic components. In this case you would also need to be certain that the hole you make does not have rough edges that could damage the wiring; you will need a snap-in grommet such as part # SWC8055.

If your flat-towing is occasional, you might prefer a magnetic type of tow bar lighting kit, such as the Road Master # RM-2120. This kit entirely bypasses the vehicle wiring and provides a 4-pole connector that is routed to the RV connector. This type of kit installs quickly and easily and avoids having to splice into your vehicle wiring. I have linked an article that explains this and the other types of tow bar lighting kits available.

I have also linked an article and video that review the components needed to safely and legally flat tow your vehicle. It is also recommended that you review your Ion owners manual for any guidance or cautions related to flat-towing.