F 150 2WD Pickup V8-4.6L (2002)
Wiring Harness HVAC: Customer Interest
Two Way Radio - Signal Loss/Static
Article No.
03-6-11
03/31/03
ELECTRICAL - HEAVY STATIC OR SIGNAL LOSS ON
TWO WAY RADIO COMMUNICATION - BI-FUEL LPG
VEHICLES ONLY
FORD:
2001-2002 F-150
Article 02-21-5 is being republished in its entirety to provide an inspection procedure.
ISSUE
Some 2001-2002 Bi-Fuel F-150 vehicles may exhibit heavy static and possible loss of signal on customer installed two-way radios operating in the range
of 47 MHz. Operation of HVAC blower motor and windshield wipers may increase severity of symptoms. This may be caused by the Compuvalve and
Blower Motor Harness.
ACTION
Inspect if latest level components have been installed. If latest level components have not been installed, install a replacement Compuvalve and a
replacement HVAC blower motor harness. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
Inspect HVAC blower motor harness to determine if vehicle was built with latest level harness or was already replaced during previous service. The
latest level harness will have a coil assembly built into it. This coil will be about 3 inches in diameter, wrapped in foam tape, and located at the blower
motor connector end of the harness (Figure 1).
Inspect Compuvalve to determine if vehicle is already equipped the latest level Compuvalve. The latest level Compuvalve will have a serial number
prefix of "LS". Any Compuvalve with a serial number of "LS" or sequentially higher, this TSB does not apply.
If the blower harness has been replaced, the TSB does not apply. If the vehicle does not have the modified blower harness, proceed with the TSB.
Disconnect J26 and check radio operation. If the electrical noise persists with J26 disconnected, this is not a compuvalve problem, do not replace the
compuvalve. If the electrical noise disappears when J26 is disconnected, replace the compuvalve. If latest level components have been installed, refer to
the appropriate Workshop Manual for audio and/or electrical noise diagnosis.
