MCI Field Notes

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© Motor Coach Industries Int’l, Inc. and its subsidiaries. All Rights Reserved.
MCI Field Note – 004
Fan Test Switch Cover
J4500 Coaches beginning with unit 66105
• Concern
• The Fan Test Switch in the remote JBox is designed as a maintained switch. This
maintained switch has been useful in keeping the radiator fan running constantly in
emergency situations. However, there have been instances when this switch has been
accidentally turned on and left on, resulting in the engine running cool and inefficient for
extended periods of time. Excessive hydrocarbon deposit buildup in the DPF is one
concern that presents itself and can create engine codes otherwise avoided with the
switch in the off position.
Fig. 1
• Interim Correction
• MCI has developed 2 options for those customers wishing to
address this:
1.
2.
Simply replace the switch with a momentary switch and eliminate the
always on feature. This can be accomplished by ordering MCI P/N
7L-8-1083 and replacing the existing fan test switch
Or keep the maintained switch as is and instead install a guard on top
of the existing switch. MCI P/N 19-11-4014 can be used to
accomplish this. See fig 1
• Next Steps
• MCI will be cutting in as standard, the switch cover as illustrated in
fig. 1. An exact VIN cut in number is currently in process.
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© Motor Coach Industries Int’l, Inc. and its subsidiaries. All Rights Reserved.