User Guide

7.3 FAULT INDICATION

OPEN CIRCUIT

The MUTT

senses no load which is often the symptom of a disconnected wire, cut

wire, poor pin connection or bad return ground. The MUTT

can detect open circuits

in two ways.

1. During Ground Integrity Test: An individual circuit will blink and no audible alerts

will be present.

2. During circuit selection: The selected circuit’s LED will blink, while simultaneously the

Open Circuit Indicator will ﬂ ash. The MUTT

will also provide an audible alert (beep).

Example: The MUTT

detects an open circuit in the Clearance Light Circuit. The

Clearance LED will blink, the Open Circuit Indicator will ﬂ ash and the MUTT

will beep.

NOTE: Open Circuit Indicator will only illuminate during circuit selection.

CROSSED CIRCUITS

The MUTT

indicates that two or more circuits are back feeding or crossed. This

can be a symptom of two wires in the same harness wearing through their insulated

coating and connecting.

1. When a crossed circuit is identiﬁ ed, the selected circuit LED will illuminate steadily

and the circuit it is crossed with will ﬂ ash. The MUTT

will also provide an audible

alert (beep).

Example: The MUTT

detects that the Clearance and Tail/Tag are crossed while the

Clearance Circuit is selected. The Clearance LED will illuminate, the Tail/Tag LED will

ﬂ ash and the MUTT

will beep.

Example: Open Circuit in Clearance Light

Example: Crossed Circuit in Clearance and Tail/Tag Lights

8.2 SETTING DESIRED WORKING PRESSURE

1. Turn the MUTT

on, by selecting Battery or External power with the Power Source

Switch.

2. Set Emergency Side Air Ball Valve to the OPEN position.

3. Turn Air Regulator Knob clockwise or counterclockwise until needle on the

Emergency Side Air Gauge points to the desired operating pressure (Most shops

prefer 80-100 PSI during testing).

Set Emergency Side Air Ball Valve to OPEN, Turn Regulator to Desired PSI