We reserve the right to make changes in design or add improvements without incur-
ring the obligation to make such changes in equipment previously manufactured.

PARTS-SERVICE

GRAM

Subject: Amplifier Harness Routing

It is possible that the “amplifier to system controller” harnesses on some trucks are improperly routed
across the high current cables at the front of the amplifiers. This may allow electrical interference or
“noise” to be picked up by the amplifier harness.

If electrical interference is suspected, due to misoperation, then the following procedure should be
followed:

Disconnect the battery and discharge the capacitor bank.
Note: Discharge  the  capacitor  bank  by  turning the key on after disconnecting the battery. The
display will come on and then go out, indicating the capacitor bank is discharged.
Inspect the amplifier harness wiring.
Ensure that the harness are routed per the diagram below.
If  it  is necessary  to reroute  the harnesses, ensure that they are reconnected to the correct ports.

FB00023

September 20, 1996

E30-50FR

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