Why Does The Roadmaster Battery Disconnect USe The Positive Terminal Post Cable

Updated 09/18/2023 | Published 09/16/2023

Products Featured in This Question

Roadmaster InvisiBrake Flat Tow Brake System - Preset

(303)

$1380.00

etrailer SD Non-Binding Tow Bar for Roadmaster Direct-Connect Base Plates - RV Mount - 6,000 lbs

(352)

$855.62

Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord

(3500)

$165.27

Roadmaster Battery Disconnect for Towed Vehicle w/ Flat Tow Brake System - Gas Only

(423)

$240.12

Roadmaster Direct-Connect Base Plate Kit - Removable Arms

(3593)

$575.00

Roadmaster Stop Light Switch Kit

(695)

$44.66

Question:

2023 Buick Encore GX AWD question? To tow 4 wheels down Buick says unhook neg battery post, put in neutral. Roadmaster says to disconnect positive post. Looks like to me if you do that that kills all power. Also I would think it would creat a dead pedal. What do your intatallers think? I woul appreciate your input. Thanks

asked by: Don F

Expert Reply:

Roadmaster released a tech bulletin about why the positive needs to be removed instead of following the vehicle's owner's manual and disconnecting the negative post cable. The reason is because if you use the disconnect on the negative side you'll lose your towed vehicle's main ground to the chassis. This means that all of the accessories that need to operate on the toad must be grounded through the connection to the motorhome which is too small of a gauge and the distance is too great to get a good ground. If you install the Roadmaster Battery Disconnect with Switch # RM-766 then you'll need to disconnect the positive post cable.

If you haven't picked out the rest of your flat towing components then I have the following recommendations:

Baseplate: Roadmaster Direct-Connect Base Plate Kit # RM32FR (no Sport Touring models).

Tow Bar: etrailer SD Non-Binding Tow Bar for Roadmaster Direct-Connect Base Plates # e74ZR. This tow bar has safety cables bracketed to the arms so you won't have to purchase them separately or worry about them dragging on the ground.

Tow Bar Wiring Kit: Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit # RM-15267. This diode kit will splice into your Buick's tail light wiring to display your motorhome's traffic signals through the tail lights of the Encore.

Braking System: The Roadmaster InvisiBrake Supplemental Braking System # RM-8700 you were looking at would be a great option for your Encore. Since your brake light switch wire isn't accessible on the Encore you'll need the Roadmaster Stop Light Switch Kit # RM62FR in order to get the signal for the indicator light so that you can see when the brakes are being activated in the Encore.