Will the InvisBrke Braking System Still Work on a 1999 Jeep Wrangler with a Disconnected Battery

Updated 05/30/2014 | Published 05/29/2014

Products Featured in This Question

Roadmaster InvisiBrake Flat Tow Brake System - Preset

(308)

$1380.00

Blue Ox 7-Wire to 6-Wire, Coiled Electrical Cord

(747)

$93.12

Roadmaster Brake-Lite Relay Kit for Towed Vehicles

(772)

$46.62

Question:

If a battery cutout switch is installed on the towed vehicle, wont this negate the operation of the indicator light in the towing vehicle? And if the battery cutout switch is not installed, when the brakes are applied will this not override a turn signal coming from the towing vehicle wiring harness? What is the power drain on the Invisibrake system? I.e., does the compressor run all the time or only when the brake is applied? Towing vehicle is a 2007 Safari Simba with 300 Cummins engine. Towed vehicle is 1999 Jeep Wrangler Sahara with 4L engine, 4WD, auto transmission and Stowmaster tow bar installed.

asked by: Steve B

Expert Reply:

The power usage specs on the InvisBrake # RM-8700 are as follows:

Voltage: 12 Volt DC
Maximum Amperage Draw: 10.8 Amps
Idle Amperage Draw: 6 milliamps
Battery Recharging Rate: up to 2 Amps

The compressor does not constantly run, only when it needs to build pressure. Overriding the turn signal from the RV depends largely on what wiring system you using to activate the lights. To get around that problem you would also need a brake light relay # RM-88400.

The braking system needs power on the towed vehicle, in this case your Jeep Wrangler, to operate. To keep a maintenance charge on the battery I recommend using a harness such as # BX88206 with the tow bar wiring you will be using so that you can run a wire from the connector at the front of the truck to the vehicle battery.

There are a couple of ways to do this. First, you can tap into the running light circuit in the tow bar wiring but to provide power to the battery the RV running lights would have to be on all the time. Or if the connector at the back of the RV has a working 12 volt circuit you could use that circuit instead.

Which ever way you choose you would just attach the wire to the appropriate corresponding pin at the back of the connector that will be at the front of the truck and the other end of that wire will go to the positive battery terminal.