Product Manual
13
OPEN CIRCUIT WARNING INDICATOR (Fig. 6)
• In the instance a selected circuit is not completed through the trailer har-
ness, (e.g., a faulty ground or no load detected), the Open Circuit warning
ashes and sounds.
• Note: Small trailer testing may initiate a false Open Circuit warning in
trailers using single LED assemblies in a circuit. Go to Small Trailer LED
Mode section (page 12) to commence testing on these types of trailers.
CROSSED CIRCUIT WARNING CHARACTERISTICS
• Red Circuit Indicators ash to show troubled circuits.
• In the instance of crossed circuits where a circuit (or circuits) other than the
selected circuit is inadvertently powered by the selected circuit, the un-
selected circuit indicators ash, while the selected indicator remains steady.
This is caused by worn wires or improperly wired plugs on the trailer. Inspec-
tion law states that there should be no crossed circuits.
• Some cases may be normal for more than one circuit to be operated by a
single circuit, such as certain ABS systems and custom aftermarket lighting.
• Refer to trailer specic wiring schematics for the unit in question.
• Crosses between brake lights and turn signals are only displayed with turn
signal selection.
GROUND INTEGRITY WARNING WITH USE OF CHASSIS GROUND CABLE
Ground Integrity has been explained in the Testing Procedure (Page 8, #6.)
• When a trailer is wired for Chassis Ground, the MUTT® ashes all circuits
(showing no ground).
• To distinguish between Chassis or Return Ground, a 10 ft. Chassis Ground
cable is supplied. Plug the 10” cord into output labeled “Chassis Ground”
(Fig. 3-N) ) and attach it to a clean, uncoated metallic area on the chassis of
the trailer.
• Then turn the MUTT® o and back on to re-test ground connections. If the
problem is resolved, this indicates a bad Chassis Ground. If the problem con-
tinues, this indicates a bad Chassis Ground through the plug. Proper ground
operation is indicated by all green lights on circuits going o and the large
green light (12 o’clock position) remains green (Fig.6).
• If all indicators remain ashing in Ground Integrity mode after a secure
clean connection has been made to the trailer, repairs to the trailer wiring
are required to complete testing.
AUTO SHUTDOWN FEATURE
In order to preserve battery life, the MUTT® enters a ‘Sleep’ Mode if inactive
after 20 minutes with the power on.
• A sound is emitted every 10-20 seconds to inform the operator of the condition.
• Activation of any test mode takes the MUTT® out of ‘sleep’ mode.