RAM 3500 Truck 4WD V10-8.0L VIN W HDC (1999)
Seat Belt Reminder Lamp: Description and Operation
Mechanical Instrument Cluster (MIC)
MECHANICAL INSTRUMENT CLUSTER (MIC)
DESCRIPTION
The Ram Truck MIC is available in 2 different versions, low line and high line. Both clusters are electromechanical units that utilize integrated
circuitry and information carried on the Chrysler Collision Detection (CCD) data bus network for control of all gauges and many of the indicator
lamps.
The lowline cluster has seventeen indicators lamps and the highline has eighteen indicators lamps. Some of the warning lamps are hardwired and
some are controlled by the cluster using the CCD bus information. The MIC is hardwired to the CTM to provide the warning lamp announcement
chimes.
These clusters also incorporate a digital Vacuum Fluorescent Display (VFD) for the odometer/trip odometer display functions. Some variations of
these clusters exist due to optional equipment and regulatory requirements.
The cluster will provide bus bias and termination and the engine controller provides a second termination. If the cluster is disconnected the bus
will not be biased.
The cluster will only be serviced as an assembly. There will be limited parts available, such as bulbs and sockets, the front lens, the trip odometer
stem cover and the rear cover assembly. No internal parts of the cluster will be serviced.
Both of these clusters include the following analog gauges:
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Coolant temperature gauge
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Fuel gauge
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Oil pressure gauge
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Speedometer
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Voltmeter.
These clusters also include provisions for the following indicator lamps:
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Airbag indicator lamp
-
Anti-lock Brake System (ABS) lamp
-
Brake warning lamp
-
Check gauges lamp
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Cruise-on indicator lamp (programmable)
-
Four-wheel drive indicator lamp
-
Headlamp high beam indicator lamp
-
Low fuel warning lamp
-
Low washer fluid warning lamp
-
Malfunction indicator (Check Engine) lamp
-
Overdrive-off indicator lamp (automatic transmission - programmable)
-
Seat belt reminder lamp
-
Service Reminder Indicator (SRI) lamp (Maintenance Required - for certain heavy-duty emissions cycle engines)
-
Transmission oil temperature warning lamp (automatic transmission - programmable)
-
Turn signal indicator lamps
-
Upshift indicator lamp (manual transmission - programmable)
-
Wait-to-start indicator lamp (Diesel Only)
-
Water-in-fuel indicator lamp (Diesel Only)
The high-line cluster includes all of the gauges and indicator lamps found in the low-line cluster, but adds an analog tachometer. Some of the
low-line cluster gauges have different positions or sizes in the high-line cluster in order to accommodate the tachometer.
Both instrument clusters include a provision for mounting the automatic transmission gear selector indicator in the lower right corner of the
cluster. Models equipped with a manual transmission have a block-out plate installed in place of this indicator.
There is a self test available for the cluster that will actuate all the gauges at their calibration points. The test will not run if the cluster sees engine
RPM or vehicle speed. This test will light all CCD controlled lamps for verification of lamp operation. It also forces the odometer Vacuum
Fluorescent Display (VFD) to perform a segment check. The self test routine can be entered by pushing and holding the trip reset button while
rotating the ignition key from the "OFF" to the "ON" position. When the word "chec" appears release the knob and the test will continue.
The cluster will provide bus bias and termination and the engine controller provides a second termination. If the cluster is disconnected the bus
will not be biased.
The instrument cluster circuitry also sends chime tone requests over a hard wired circuit to the Central Timer Module (CTM) when it monitors
certain conditions or inputs. The CTM replaces the chime or buzzer module.
