A/C Clutch electrical problems [Archive] - Dodge Talk Community Forum

96Grand

05-02-2006, 08:02 PM

I would start w/ the compressor clutch fuse located in the engine compartment. Then work your way to the tests below.

Testing and Inspection

ELECTRICAL CIRCUIT
The air conditioning compressor clutch electrical circuit is controlled by the Powertrain Control Module. It is located in the engine compartment outboard of the battery. If the compressor clutch (http://www.alldatadiy.com/alldata/AFI~V6597046~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/34865609/34865610) does not engage verify refrigerant (http://www.alldatadiy.com/alldata/AFI~V6597046~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/56273766) charge. If the compressor clutch still does not engage check for battery voltage at the pressure transducer located on the liquid line. If voltage is not detected, See: Diagrams\Electrical (http://www.alldatadiy.com/alldata/AFI~V6597046~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/34866127/34849368)

TRANSDUCER VOLTAGE
If voltage is detected at the pressure transducer, connect pressure transducer and check for battery voltage between the compressor clutch (http://www.alldatadiy.com/alldata/AFI~V6597046~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/34865609/34865610) connector terminals. If voltage is detected, perform A/C Clutch Coil Tests.

TESTS

Verify battery state of charge. (Test indicator in battery should be green).
Connect an ampmeter (0-10 ampere scale) in series with the clutch coil terminal. Use a voltmeter (0-20 volt scale) with clip leads measuring voltage across the battery and A/C clutch (http://www.alldatadiy.com/alldata/AFI~V6597046~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/34865609/34865610).
With A/C control in A/C mode and blower at low speed, start the engine and run at normal idle.
The A/C clutch (http://www.alldatadiy.com/alldata/AFI~V6597046~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/34865609/34865610) should engage immediately and the clutch voltage should be within two volts of the battery voltage. If the A/C clutch does not engage, test the fuse.
The A/C clutch coil is acceptable if the current draw is 2.0 to 3.7 amperes at 11.5-12.5 volts at clutch coil. This is with the work area temperature at 21°C (70°F) . If voltage is more than 12.5 volts , add electrical loads by turning on electrical accessories until voltage reads below 12.5 volts .
If coil current reads zero, the coil is open and should be replaced. If the ammeter reading is 4 amperes or more, the coil is shorted and should be replaced. If the coil voltage is not within two volts of the battery voltage, test clutch coil feed circuit for excessive voltage drop.
Service and Repair

CLUTCH COIL REMOVAL

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1. Remove the compressor shaft bolt. A band type oilfilter removal tool can be placed around the clutch plate to aid in bolt removal.

CAUTION: Do not use screwdrivers between the clutch plate assembly and pulley to remove front plate as this may damage the front plate assembly.
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2. Tap the clutch plate with a plastic hammer and remove clutch plate & shim.

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3. Remove pulley retaining snap ring with snap ring pliers (C-4574), and slide pulley assembly off of compressor.

4. Remove coil wire clip screw and wire harness.

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Remove snap ring retaining field coil onto compressor housing. Slide field coil off of compressor housing.
Examine frictional faces of the clutch pulley and front plate for wear. The pulley and front plate should be replaced if there is excessive wear or scoring. If the friction surfaces are oily, inspect the shaft nose area of the compressor for oil and remove the felt from the front cover. If the compressor felt is saturated with oil, the shaft seal is leaking and will have to be replaced.
Check bearing for roughness, excessive leakage or grease. If grease from bearing has contaminated the faces of the pulley or front plate, they should be replaced. If the bearing is rough or binds, replace clutch pulley and front plate assembly
CAUTION: The clutch pulley and the front plate were mated at the factory by a burnishing operation. No attempt should be made to separately replace either part. This will result in clutch slippage due to insufficient contact area.
INSTALLATION

Align pin in back of field coil with hole in compressor end housing, and position field coil into place. Make sure that lead wires are properly routed, and fasten with the wire clip screw.
Install field coil retaining snap ring with snap ring pliers. The bevel side of the snap ring facing outward. Also both snap ring eyelets must be to the right or left of the pin on compressor. Press snap ring to make sure it is properly seated in the groove.
CAUTION: If snap ring is not fully seated it will vibrate out, resulting in a clutch failure and severe damage to the front face of the compressor.

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Install pulley assembly to compressor. If necessary, tap gently with a block of wood on the friction surface.
CAUTION: Do not mar the pulley frictional surface.

Install pulley assembly retaining snap ring (bevel side outward) with snap ring pliers. Press the snap ring to make sure it is properly seated in the groove.
If the original front plate assembly and pulley assembly are to be reused, the old shim(s) can be used. If not, place a trial stack of shims, 1 mm (0.040 in.) thick, on the shaft against the shoulder.
Install front plate assembly onto shaft.
With the front plate assembly tight against the shim(s), measure the air gap between front plate and pulley face with feeler gauges. The air gap should be between 0.5 and 0.9 mm (0.020 and 0.035 inch) If proper air gap is not obtained, add or subtract shims until desired air gap is obtained.
Install compressor shaft bolt. Tighten to 15.5 to 19.5 N.m (135 to 175in. lbs.) .
NOTE: Shims may compress after tightening shaft nut. Check air gap in four or more places to verify if air gap is still correct. Spin pulley for final check.
CLUTCH BREAK-IN
After a new clutch has been installed, check the voltage and amperage to the clutch (determine it to be satisfactory). Then cycle the A/C clutch (http://www.alldatadiy.com/alldata/AFI~V6597110~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/34865608/34865609/34865610) approximately 20 times (5 sec. on and 5 sec. off) . For this procedure, set the system to the A/C mode, using high blower, and engine rpm at 1500-2000 . This procedure (burnishing) will seat the opposing friction surfaces and provide a higher clutch torque capability.