Product Manual

7.2 GROUND INTEGRITY TEST

Each time the MUTT

is powered on, it automatically runs a Ground Integrity Test. A good

ground connection must be established for the MUTT

to operate a trailer’s electrical system.

1. Immediately after power up, the green lights around the control knob will illuminate.

2. A solid/healthy ground connection is indicated by a steadily illuminated Ground

Integrity Indicator.

3. Bad/poor ground or bad cable condition is indicated by all of the LED’s blinking

simultaneously. See ESTABLISHING A CHASSIS GROUND below.

4. When one or more green circuit LEDs blink while the Ground Integrity Indicator

is steadily illuminated indicates that a solid ground has been established, but an

open circuit has been detected. Refer to OPEN CIRCUIT on pg. 18.

CHASSIS AND PIN GROUNDS

A poor ground warning may be an indication that the connected trailer is only wired

for chassis ground. There are two ground types. 1) Pin Ground: The ground wire

from each light assembly is wired through the main harness up into the trailer plug.

2) Chassis Ground: The ground wire from each light assembly is grounded directly to

the trailer chassis. Ground with the truck is established at the king pin.

ESTABLISHING A CHASSIS GROUND

1. To simulate the king pin on a chassis ground

connection and bypass the ground integrity fault,

plug the supplied 10 ft. chassis ground cable into

the MUTT

’s Chassis Ground Outlet.

2. Using the alligator clip, attach the other end of the

chassis ground cable to the chassis of the trailer.

3. Be sure that you are attaching to a clean, dry metal for an effective ground.

GOOD GROUND BAD/POOR GROUND

DO NOT

Assume that a Bad

Ground Warning is a

Result of a Faulty Trailer.

Check Cable Connection.

Put the Chassis Ground Cable into the Outlet

8.5 EMERGENCY AIR EXHAUST

To apply the parking brake at any time during testing, simply turn the Emergency

Side Air Ball Valve to the EXHAUST position.

1. Make sure the Power Source Switch on the Control Panel is on.

2. Set the Emergency Side Air Ball Valve to the EXHAUST position to exhaust air.

Set Emergency Side Air Ball Valve to EXHAUST