4 Wire Brakeswitch
Before starting make sure your Exhaust
brake system is in good working order. You would be amazed at the number
of coaches running around with a stuck Exhaust brake. (Usually from lack
of use) Also this system requires your coach turn on brake lights when
exhaust brake is in use. (If your coach does not turn on brake light
call us for instructions.
Install Instructions for
BrakeSwitch 4 Wire System
recommend you read the entire instructions before starting. This is to
give you an understanding of what is to be done and may prevent moving
Tools required to install BrakeSwitch:
1. A 12-volt test light. Wire cutter Screw Driver Awl
As you look at BrakeSwitch control box there are 4 wires:
1. 2 2ft Red wires. These will be used to splice into wire
from IGN switched source.
2. 1 2ft Black wire. This is to be attached to any good
3. 1 5ft Purple Wire This is to be attached to Brake Light
source. Such as Brake light switch.
Locate spot for Control Box to be installed.
(You may fasten it to wall or use anything to tie it to. We just want to
secure the box to keep it from swinging loose) Velcro works great to
attach to wall.
Your original switch is still your ON/OFF switch.
We recommend it should always be in the ON Position.
(We call this “set it and forget it”)
EXCEPT: slick and ice covered roads system should be OFF!
1. Of the group of wires going to
your cockpit exhaust control switch, find the 12-volt power feed
line. (Ignition switch must be ON for this.) After you have
determined which is the supply line turn the ignition switch off.
This wire is to be cut. Now take either Red wire from the Control
box one is to be spliced into one side of cut wire and the other to
the other. (This will complete circuit when BrakeSwitch is
2. Now its time to connect the purple wire to brake light source.
(On some coaches there is a brake light source in cockpit, If you have this please use it.)
If no source is found in cockpit Look for the soft spot in the
firewall. (Most coaches have a
spot where many wires are run thru the firewall and then are filled
with rubber or Styrofoam.)
(Some customers report they have made a small hole in back of boot
around steering column. If
this is used wire will come out just above the brakelight switches.
If there is no soft spot you
may need to drill a small hole to feed the Purple wire thru. Locate
brake light switch, it should
be, under the floor, directly under the brake pedal or can be an air
operated switch located in the brake line. (In most installations
this switch can found close to
firewall) Use test light, one side should have power and the other
NOT. (Powered only when
brake is applied.) Using quick clips connect the non-power side.
4. Connect Black wire to any good ground.
This completes the installation. Now for
road test. With speed above 15 MPH apply brakes, your transmission
should pre-select to a lower gear and exhaust brake will close. A touch
of the throttle will open Exhaust brake. If you use the Exhaust brake to
lower speed it will release around 7MPH.