Product Manual
18
NOTE: In some cases, a crossed circuit may be a normal function of advanced
diagnostic testing, such as with certain ABS systems.
SHORT/OVERLOADED CIRCUIT
Short circuits or overloads can occur when a positive, hot wire touches ground.
They can also occur due to faulty lights or connectors.
1. If a short or overloaded circuit is suspected, the MUTT
®
will instantly stop
powering the circuit.
2. The Overload Warning Indicator will then fl ash, along with the selected circuit’s
LED. The ammeter needle will also max out and return to 0.
3. The MUTT
®
will now automatically enter Pulsar Mode. During Pulsar Mode, the
MUTT
®
will attempt to reapply power to the faulty circuit every 3 seconds for an
indefi nite period of time. After power is applied, if a short is still present, steps 1-3
will automatically repeat.
Example: The MUTT
®
detects a short in the Clearance Light Circuit. The Clearance
LED and Overload Warning Indicator will fl ash and a warning beep will sound. The
MUTT
®
will now enter Pulsar Mode.
NOTE: Pulsar Mode can be a useful troubleshooting tool for fi nding dead and
intermittent shorts.
Example: Short Circuit in the Clearance Light
23
8.3 LEAK DOWN TESTING
You must always test the Emergency Side before testing the Service Side. Trying to
test the Service Side fi rst will result in erroneous readings.
EMERGENCY SIDE LEAK DOWN TESTING
1. After setting the desired working pressure, set the Emergency Side Air Ball Valve to
the CLOSED position. This will begin the leak down test.
2. Observe the needle on the air gauge and note any PSI drop after pressure stabilizes.
3. Look for air loss according to your local specifi cations by noting consistent air
drop over time. If air pressure continues to drop at an unacceptable rate, you can
turn your air supply back on by setting the Emergency Side Air Ball Valve to OPEN
and attempt to fi nd the source of the leak in the air system.
SERVICE SIDE LEAK DOWN TESTING
1. Set the Emergency Side and Service Side Air Ball Valves to the OPEN position.
Set the Service Side Brake Control Switch to the PRESSURIZE position. (This fi lls
the Service Side air lines.)
2. Once the Service Side is fully charged, set the Service Side Air Ball Valve to the CLOSED
position.
3. Observe the needle on the air gauge and note any PSI drop after pressure stabilizes.
4. Look for air loss according to your local specifi cations by noting consistent air
drop over time. If air pressure continues to drop at an unacceptable rate, you can
turn your air supply back on by setting the Service Side Air Ball Valve to OPEN
and attempt to fi nd the source of the leak in the air system.
Set Emergency Side Air Ball Valve to CLOSED
Set Service Side Air Ball Valve to CLOSED