12 - Fan Clutches Table of Contents 12-1 Part Number Index 12-3 General Information Foreword 12-4 Core Return Guidelines 12-5 Application Guidelines 12-6 Horton Components 12-12 Horton Repair Kit Reference 12-14 Horton® Fan Clutches Caterpillar, Cummins, & Detroit in MCI Applications (HT/S Advantage TM ) 12-15 Caterpillar 3176 (Model S & HT/S Advantage TM ) 12-16 Caterpillar 3306 (HT/S Advantage TM ) 12-17 Caterpillar 3406 (Model S & HT/S Advantage TM ) 4 Belt Groove 12-18 6, 8, 10K Multi-Groove 12-20 Caterpillar 3406, 3406B (Direct Drive) 12-21 Caterpillar 3406, 3406E, C11, C13, C15 & C16 (DriveMaster®) 12-22 Cummins (EC450®) 12-23 Cummins "C" Series (Model S) 12-24 Cummins ISB (DriveMaster®) 12-25 Cummins ISL (DriveMaster®) 12-26 Cummins ISM (DriveMaster®) 12-27 Cummins ISX (DriveMaster®) 12-28 Cummins ISX (HT/S Advantage TM ) 12-29 Cummins ISX & N14 (HT/S Advantage TM ) 12-30 Cummins L10 Series (Direct Drive) 12-31 Cummins L10 Series (Model S & HT/S Advantage TM ) 12-32 Cummins L10 & N14 (Model S) 12-34 Cummins Ford NTC Series (Model S) 12-35 Cummins NT, NTC (Direct Drive) 12-36 Cummins NTC, NT88, 444 Series (Model S & HT/S Advantage TM ) 12-37 Cummins N14 Series (Model S & HT/S Advantage TM ) 12-38 Detroit 6V92, 8V92, 8V71, 6V71 & 12V71 Series (Model S) 12-39 Detroit 60 Series (Direct Drive) 12-40 Detroit 60 Series (DriveMaster®) 12-41 Detroit 60 Series (Model S & HT/S Advantage TM ) 3 & 4 Belt Groove 12-42 6, 10, 14K Multi-Groove 12-43 Table of Contents 12-FAN CLUTCHES 12 - 1
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12 − Fan ClutchesTable of Contents 12−1Part Number Index 12−3General Information Foreword 12−4 Core Return Guidelines 12−5 Application Guidelines 12−6 Horton Components 12−12 Horton Repair Kit Reference 12−14Horton® Fan Clutches Caterpillar, Cummins, & Detroit in MCI Applications (HT/S AdvantageTM) 12−15 Caterpillar 3176 (Model S & HT/S AdvantageTM) 12−16 Caterpillar 3306 (HT/S AdvantageTM) 12−17 Caterpillar 3406 (Model S & HT/S AdvantageTM) 4 Belt Groove 12−18 6, 8, 10K Multi−Groove 12−20 Caterpillar 3406, 3406B (Direct Drive) 12−21 Caterpillar 3406, 3406E, C11, C13, C15 & C16 (DriveMaster®) 12−22 Cummins (EC450®) 12−23 Cummins "C" Series (Model S) 12−24 Cummins ISB (DriveMaster®) 12−25 Cummins ISL (DriveMaster®) 12−26 Cummins ISM (DriveMaster®) 12−27 Cummins ISX (DriveMaster®) 12−28 Cummins ISX (HT/S AdvantageTM) 12−29 Cummins ISX & N14 (HT/S AdvantageTM) 12−30 Cummins L10 Series (Direct Drive) 12−31 Cummins L10 Series (Model S & HT/S AdvantageTM) 12−32 Cummins L10 & N14 (Model S) 12−34 Cummins Ford NTC Series (Model S) 12−35 Cummins NT, NTC (Direct Drive) 12−36 Cummins NTC, NT88, 444 Series (Model S & HT/S AdvantageTM) 12−37 Cummins N14 Series (Model S & HT/S AdvantageTM) 12−38 Detroit 6V92, 8V92, 8V71, 6V71 & 12V71 Series (Model S) 12−39 Detroit 60 Series (Direct Drive) 12−40 Detroit 60 Series (DriveMaster®) 12−41 Detroit 60 Series (Model S & HT/S AdvantageTM) 3 & 4 Belt Groove 12−42 6, 10, 14K Multi−Groove 12−43
Table of Contents 12−FAN CLUTCHES
12 − 1
Mack ASET AI (DriveMaster® Two−Speed) 12−44 Volvo VE D12 (DriveMaster PolarExtreme®) 12−45KysorTM/Borg Warner Style Fan Clutches 12−46Gold Top® Kits 12−47Horton® Fan Clutch Components/Repair Kits Major Overhaul Kits 12−48 Super Kits 12−49 Seal Kit 12−50 Facing/Liner Kit 12−51 Spacers & Adapters 12−52 Thermal Switches 12−53 Solenoid Valve & Filter 12−54 Fan Blades 12−55KysorTM/Borg Warner Style Components KysorTM/Borg Warner Style Kits and Components 12−56 Temperature Controls/Shutterstats 12−57Maintenance Troubleshooting 12−58 Troubleshooting 12−59 Troubleshooting 12−62
12−FAN CLUTCHES Table of Contents
12 − 2
Part Number Type Page #RF14200K S 12−47RF142561K S 12−47RF14256K S 12−47RF142SK S 12−47RF145K S 12−47RF14LK S 12−47RF14SBLK S 12−47RF14SK S 12−47RF35029 S 12−57RF35030 S 12−57RF35031 S 12−57RF36029 S 12−57RF36030 S 12−57RF36031 S 12−57RF790000X S 12−37RF790001X S 12−38RF790002X S 12−37RF790003X S 12−39RF790004X S 12−39RF790005X S 12−18RF790007X S 12−18RF790008X S 12−35RF790009X S 12−42RF790010X S 12−32RF790011X S 12−42RF790012X S 12−24RF790013X S 12−24RF790014X S 12−16RF790015X S 12−16RF790016X S 12−32RF790017X S 12−32RF790018X S 12−42RF790021X S 12−34RF790023X S 12−32RF791000X S 12−37RF791001X S 12−32RF791002X S 12−18RF791003X S 12−18RF791004X S 12−38RF791005X S 12−18RF791006X S 12−38RF791007X S 12−18RF791008X S 12−18RF791009X S 12−38RF791010X S 12−38RF791011X S 12−42RF791012X S 12−17RF791013X S 12−18RF791014X S 12−18RF791015X S 12−16RF791016X S 12−37RF791017X S 12−18RF791018X S 12−32RF791019X S 12−38RF791020X S 12−18RF791021X S 12−32RF791022X S 12−32RF791023X S 12−43RF791024X S 12−42RF791025X S 12−16RF791026X S 12−38RF791027X S 12−18RF791028X S 12−17RF791029X S 12−32RF791030X S 12−32RF791031X S 12−43RF791032X S 12−32RF791033X S 12−43RF791034X S 12−32RF791035X S 12−16RF791036X S 12−32RF791037X S 12−42RF791038X S 12−20RF791039X S 12−15RF791040X S 12−15RF791041X S 12−15RF791069X S 12−20RF791073X S 12−30RF791076X S 12−20RF791093X S 12−29RF799011X S 12−27
Part Number Type Page #RF799065X S 12−41RF799067X S 12−41RF799103X S 12−22RF799168X S 12−28RF799223X S 12−41RF799334X S 12−22RF799339X S 12−22RF799437X S 12−22RF799809X S 12−22RF80001X S 12−46RF80005X S 12−46RF8000KCK S 12−56RF8000KSK S 12−56RF8101K S 12−56RF8201K S 12−56RF8202K S 12−56RF8203K S 12−56RF8204K S 12−56RF85001X S 12−46RF85002X S 12−46RF85003X S 12−46RF8500KCK S 12−56RF8500KLK S 12−56RF8500KSK S 12−56RF88001X S 12−46RF88003X S 12−46RF8800KCK S 12−56RF8800KLK S 12−56RF991762202 S 12−55RF991762502 S 12−55RF991813253 S 12−55RF991900 S 12−31RF991902 S 12−36RF991903 S 12−36RF991918 S 12−21RF991933 S 12−36RF992013 S 12−40RF993249 S 12−54RF993272 S 12−54RF993273 S 12−54RF993280 S 12−54RF993282 S 12−54RF993284 S 12−54RF993286 S 12−54RF993287 S 12−54RF993293 S 12−54RF993294 S 12−54RF993295 S 12−54RF993296 S 12−54RF993343 S 12−54RF993412 S 12−54RF993427 S 12−54RF993428 S 12−54RF993603 S 12−53RF993605 S 12−53RF993606 S 12−53RF993607 S 12−53RF993610 S 12−53RF993615 S 12−53RF993616 S 12−53RF993617 S 12−53RF993619 S 12−53RF993625 S 12−53RF993626 S 12−53RF993630 S 12−53RF993653 S 12−53RF993654 S 12−53RF993655 S 12−53RF993658 S 12−53RF993665 S 12−53RF994002 S 12−54RF994039 S 12−52RF994040 S 12−52RF994052 S 12−52RF994053 S 12−52RF994072 S 12−52RF994073 S 12−52RF994074 S 12−52RF994105 S 12−55RF994116 S 12−55RF994117 S 12−55
Part Number Type Page #RF994155 S 12−55RF994156 S 12−55RF994205 S 12−50RF994305 S 12−49RF994307 S 12−49RF994314 S 12−48RF994315 S 12−48RF994319 S 12−51RF994322 S 12−49RF994343 S 12−49RF994346 S 12−50RF994349 S 12−51RF994900 S 12−49RF994985 S 12−49RF996019 S 12−23RF996048 S 12−23RF999110 S 12−25RF999285 S 12−41RF999416 S 12−26RF999801 S 12−28RF999809 S 12−22RF999820 S 12−45RF999947 S 12−44
Part Number Type Page #
Type "O" = OEM P/N, Type "S" = Service P/NIf OEM part # is not found on page listed, refer to the MCR for applicable cross reference.
Part Number Index 12−FAN CLUTCHES
12 − 3
PURPOSE OF THIS SECTIONThis section is designed as a reference for Haldex Commercial Vehicle Systems new and remanufactured air brake systemcomponents and accessories, sold under the Haldex and Midland product names. Products described include all pertinentinformation needed to replace an OEM installed component or to help design an original installation. If there is a servicenumber for a given part, it is noted in the product number table.
DESIGN FLEXIBILITYThe products presented in this section are described by function and usage. Technical data and mounting configurationsare also provided. Throughout this section, reference is made to numerous specific OEM applications. This section is not,however, intended to be a mutually exclusive listing of all part numbers and designs available. Should the need for a designnot presented occur, contact your Haldex Commercial Vehicle Systems sales representative for additional information.
WARRANTY INFORMATIONProper service and repair are important to the safe, reliable operation of any motor vehicle. To prevent personal injuryand/or vehicle damage, careful and cautious service procedures recommended by the vehicle manufacturer should befollowed by anyone servicing a motor vehicle. For details on warranty of Haldex Commercial Vehicle air brake systemcomponents and accessories, refer to L20221 Aftermarket Warranty Policy. For warranty returns, use L90005 WarrantyAdjustment Form. To obtain further information, visit the www.haldex.com website, select North America/English in dropdown box then search for Warranty.
ORDERING PROCEDUREMost customers can place electronic orders on the www.haldex.com website by obtaining a username and password or byusing EDI. For additional information about electronic orders or to place an order by phone or fax, contact CustomerService in U.S. or Canada at numbers listed below:
U.S. Customer Service: Canada Customer Service:Phone: 800−643−2374 Phone: 800−267−9247Fax: 800−533−1941 Fax: 519−826−9497Mail: Commercial Vehicle Systems
Haldex Brake Products CorporationAttn: Customer Service Department10930 N. Pomona Ave.Kansas City, MO 64153
Mail: Commercial Vehicle SystemsHaldex LimitedCanadian Distribution CentreAttn: Customer Service Department525 Southgate Drive, Unit 1Guelph, Ontario N1G 3W6
IMPORTANT NOTICEThe data listed herein is correct to the best of Commercial Vehicle Systems knowledge and belief, having been compiledfrom reliable and official sources of information. However, COMMERCIAL VEHICLE SYSTEMS CANNOT ASSUME ANYRESPONSIBILITY for possible error or misapplication of the product. Final determination of the suitability of the productsfor the use contemplated by the Buyer is the sole responsibility of the Buyer. Commercial Vehicle Systems shall have noresponsibility in connection with this suitability. It is not our intention to imply that any of the components in this catalog inconnection with an engine make or model are made by any engine manufacturer.
Copyright 2009Commercial Vehicle Systems
Haldex Brake Products Corporation10930 N. Pomona Ave.
Kansas City, MO 64153
All rights reserved.Materials may only be reproduced with written permission of Commercial Vehicle Systems.
12−FAN CLUTCHES Foreword
12 − 4
WHAT YOU NEED TO LOOK FOR:
Core is complete and not disassembled. The fan clutch core must include a bracket, sheave, PFD (pistonfriction disk),and an air chamber.
1.
The fan clutch core cannot be broken, cracked, welded or galled.2.
The sheave and air chamber must spin freely.3.
Core has not been damaged by non−operational causes such as fire, rust, or rough handling.4.
The fan clutch core must be a part number specified by Haldex that is acceptable for exchange.5.
APPLICABLE CREDIT:
If none of the above conditions exist (1, 2, 3 or 4), full credit is applicable.1.
If any one of the above conditions exist, fifty percent (50%) credit is applicable.2.
If two or more of the above conditions exist, no credit is applicable.3.
Refer to Core Policy L00036 for additional information on core credits, core returnprocedures, core changes, core acceptance, core refunds, and freight.
PRINCIPLE COMPONENTPARTS:
PROCEDURES FOR CORE IDENTIFICATION:
A. Sticker Check A "Good" core should have a product number which matches the listed acceptableproduct numbers. (If sticker is not available, go to steps B & C).
B. Visual Check A "Good" core should match match one of the graphics and notes listed on thefollowing pages.
CASTING NUMBER LOCATIONS:
Sheave On the edge of the back rim
Bracket Front surface near shaft
Air Chamber Front surface (smooth type has no casting numbers)
Core Return Guidelines 12−FAN CLUTCHES
12 − 5
VEHICLEMODEL & YEAR ENGINE MAKE & MODEL OEM #
HORTONREMANNUMBER
MIDLANDSERVICENUMBER
BLUEBIRD
1988 & UP, School Bus Cummins C−Series 980008790012 RF790012X
FORD
1974−86, CL9000
1973 & UP, L9000, W9000
1977 & UP, CL9000
1974 & UP, L9000
1975 & UP, W−WT9000
1978 & UP, CL9000
Caterpillar 3406
Cummins PT270, NTC Series
Cummins NTC Series
Detroit Diesel 8V71, 6V92
Detroit Diesel 8V71T, TT, TA, 6V92T, TT 8V92TADetroit Diesel 6V92TT, 8V92TT
990058
990019
990026
990031
990031
990031
790005
790008
790002
790003
790003
790003
RF790005X
RF790008X
RF790002X
RF790003X
RF790003X
RF790003X
FREIGHTLINER
10/88 & UP, ALL
1988 & UP, ALL
1989 & UP, ALL
1989 & UP, Replaces HT550 & D.H.1990 & UP, ALL
1975 & UP, ALL
1987 & UP, ALL
1988 & UP, ALL
1989, COE & Conventional1990 & UP, FLD112
1989 & UP, ALL
1970 & UP, ALL
1975 & UP, ALL
1988 & UP, ALL
Caterpillar 3176
Caterpillar 3406 ATTAC
Caterpillar 3406 ATAAC
Caterpillar 3406
Caterpillar 3306
Cummins NTC Series
Cummins NTC Series, Big Cam IVCummins NTC Series
Cummins L−10
Cummins L−10
Cummins L−10
Detroit Diesel 8V71N & T
Detroit Diesel 8V92T, TA, 8V71
Detroit Diesel 60 Series
990083
991022
991021
−
991050
990026
991015
991084
990006
990092
990007
990031
990047
990041
790015
791008
791007
791013
791012
790002
791016
791009
790010
790016
790017
790003
790004
790009
RF790015X
RF791008X
RF791007X
RF791013X
RF791012X
RF790002X
RF791016X
RF791009X
RF790010X
RF790016X
RF790017X
RF790003X
RF790004X
RF790009X
12−FAN CLUTCHES Application Guidelines
12 − 6
VEHICLEMODEL & YEAR ENGINE MAKE & MODEL OEM #
HORTONREMANNUMBER
MIDLANDSERVICENUMBER
HENDRICKSON
1975 & UP, ALL Detroit Diesel 8V71N & T, 6V92TT, 8V92T
(1) Air Chamber Seal, (1) Face Seal, (2) RetainingRings, (1) Air Cartridge Assembly, (1) Friction Liner,(1) Spring Housing/Piston, (1) Cage Nut − used for
repairs only.
RF994985 Drivemaster Super Kit forHorton Fan Clutch
(1) Air Chamber Seal, (1) Face Seal, (2) RetainingRings, (1) Air Cartridge Assembly, (1) Friction Liner,(1) Spring Housing/Piston, (1) Cage Nut − used for
repairs only.
Horton® Fan Clutch Components/Repair Kits12−FAN CLUTCHES
Overtemp warning switch is too faraway from the fan temp switch.
3.
Temp gauge is faulty (reads high).4. Fan temp switch is faulty.5.
Check solenoid plumbing.Replumb solenoid valve.
1.
Replace overtemp warningswitch.
2.
Move overtemp warning switchas close to the fan temp switchas possible.
3.
Replace temp gauge.4.
Replace fan temp switch.5.
Fan engages at low enginetemperatures while vehicle ismoving.
Normal condition in extremely hotweather or at slow vehicle speeds inwarm weather.
1.
Faulty temp gauge.2.
A/C system overcharged or condensercovered with debris.
3.
Refrigerant pressure switch may befaulty.
4.
Fan temp switch is faulty, if fanengages at low engine temp and A/Cis OFF.
5.
Normal condition in hotweather.
1.
Replace temp gauge orsender.
2.
Check A/C system.3.
Replace pressure switch ifnecessary.
4.
Replace fan temp switch.5.
Fan won't run under anycondition. Air line may be leaking (Horton/Evans
air−on fan drives).1.
Wiring may be shorted and/or fuses,circuit breakers blown.
2.
Air solenoid may be faulty. Test airsolenoid valve by shorting across theterminals of the temp switch toenergize the air solenoid valve and toactivate the fan drive.
3.
Check air lines. Fix wherenecessary.
1.
Check wiring, fuses, and circuitbreakers.
2.
If solenoid does not activate,replace solenoid.
3.
Troubleshooting 12−FAN CLUTCHES
12 − 59
Normally Closed Fan Clutches
Problem Possible Cause Solution
Fan runs all the time whenthe air conditioning is OFF. Manual override switch is ON.1.
Air solenoid valve may be faulty orplumbed incorrectly.
2.
Air line to clutch may be leaking(Bendix/Kysor air−off fan drives).
3.
Fan temp switch may be stuck open;with engine temp below 180°F shortacross terminals, if fan turns off,switch is faulty.
4.
Pressure switch may be stuck open;turn off A/C system, if fan continues torun, short across pressure switch, iffan stops, pressure switch isdefective.
Fan runs all the time whenthe air conditioning is ON. This is a normal condition in
extremely hot weather; spray wateron A/C condenser (fan shoulddisengage for a short period of timeand then re−engage after waterevaporates).
1.
Air conditioning system may beover−charged or condenser coveredwith debris. Turn OFF the A/Csystem; if the fan stops, therefrigerant pressure switch isfunctioning.
2.
Pressure switch may have drifted outof calibration; use pressure gauge tocompare actual fan−on and fan−offpressures vs. specified pressures.
3.
Normal condition in hotweather.
1.
Service A/C system. CheckA/C pressure and condenser.
2.
If out of calibration, replacepressure switch.
3.
Fan operation is erratic.Loose electrical connection.1.
Fan temp or pressure switch may befaulty.
2.
Check wiring; fix wherenecessary.
1.
If other system componentsand connections check outokay, (a) replace pressureswitch if erratic fan operationis associated with airconditioning at idle or (b)replace fan temp switch if theerratic operation occursprimarily when the engine ishot.
2.
Fan cycles frequently whenengine is hot.
The fan should remain engaged long enoughto reduce temperature 7−10єF. The fan tempswitch is defective if the fan disengages afteronly a 3−4є reduction.
Replace fan temp switch.
12−FAN CLUTCHES Troubleshooting
12 − 60
Normally Closed Fan Clutches
Problem Possible Cause Solution
Fan cycles frequently whenvehicle is stationary with A/CON.
Up to 4 cycles per minute is a normal conditionfor conventional control systems; turn off airconditioning system and cycling should stop.
To reduce cycling by up to 90%, installan Index K7 fan control system.
Fan turns on wheneverignition is on (turns off whenengine gets hot).
Air solenoid valve plumbed backwards. Check solenoid installation instructions;plumb correctly.
Control system fuses blown.If fuse blows whenever the ignition isturned on, the problem is most likelyrelated to a fault in the wiring.
1.
If the fuses blow only when the fanengages, the fault is probablyassociated with the solenoid valve.
2.
Check wiring, fix wherenecessary.
1.
Use an ohmmeter to check fora shorted solenoid coil (thecoil resistance should begreater than 14 ohms). Ifshorted, replace air solenoidvalve.
2.
Troubleshooting 12−FAN CLUTCHES
12 − 61
Normally Open Fan Clutches
Problem Possible Cause Solution
Fan won't engage whenmanual override is turned on.
Manual override switch, air solenoid valve orrelated plumbing or wiring is faulty.
Replace faulty component.
Fan won't cycle on when airconditioning test is performed.
Outside air temperature is too low, there is alow refrigerant charge or refrigerant pressureswitch is faulty.
Check air conditioning system.1. Replace pressure switch ifrequired.
Overtemp warning switch is too faraway from the fan temp switch.
3.
Temp gauge is faulty (reads high).4. Fan temp switch is faulty.5.
Check solenoid plumbing.Replumb solenoid valve.
1.
Replace overtemp warningswitch.
2.
Move overtemp warning switchas close to the fan temp switchas possible.
3.
Replace temp gauge.4.
Replace fan temp switch.5.
Fan engages at low enginetemperatures while vehicle ismoving, with air conditioningON.
Normal condition in extremely hotweather or at slow vehicle speeds inwarm weather.
1.
Faulty temp gauge.2.
A/C system overcharged or condensercovered with debris.
3.
Refrigerant pressure switch may befaulty.
4.
Fan temp switch is faulty if fanengages at low engine temp and A/Cis OFF.
5.
Normal condition in hotweather.
1.
Replace temp gauge orsender.
2.
Check A/C system.3.
Replace pressure switch ifnecessary.
4.
Replace fan temp switch.5.
Fan won't run under anycondition. Air line may be leaking (Horton/Evans
air−on fan drives).1.
Wiring may be shorted and/or fuses,circuit breakers blown.
2.
Air solenoid may be faulty. Test airsolenoid valve by shorting across theterminals of the temp switch toenergize the air solenoid valve and toactivate the fan drive.
3.
Check air lines. Fix wherenecessary.
1.
Check wiring, fuses, and circuitbreakers.
2.
If solenoid does not activate,replace solenoid.
3.
12−FAN CLUTCHES Troubleshooting
12 − 62
Normally Open Fan Clutches
Problem Possible Cause Solution
Fan runs all the time whenthe air conditioning is OFF. Manual override switch is ON.1.
Air solenoid valve may be faulty orplumbed incorrectly.
2.
Air line to clutch may be leaking(Bendix/Kysor air−off fan drives).
3.
Fan temp switch may be stuck closed;with engine temp below 180°Fdisconnect wiring, if fan turns off,switch is faulty.
4.
Pressure switch may be stuck closed;turn off A/C system, if fan continues torun, disconnect wiring to pressureswitch, if fan stops, pressure switch isdefective.
Fan runs all the time whenthe air conditioning is ON. This is a normal condition in
extremely hot weather; spray wateron A/C condenser (fan shoulddisengage for a short period of timeand then re−engage after waterevaporates).
1.
Air conditioning system may beover−charged or condenser coveredwith debris. Turn OFF the A/Csystem; if the fan stops, therefrigerant pressure switch isfunctioning.
2.
Pressure switch may have drifted outof calibration; use pressure gauge tocompare actual fan−on and fan−offpressures vs. specified pressures.
3.
Normal condition in hotweather.
1.
Service A/C system. CheckA/C pressure and condenser.
2.
If out of calibration, replacepressure switch.
3.
Fan operation is erratic.Loose electrical connection.1.
Fan temp or pressure switch may befaulty.
2.
Check wiring; fix wherenecessary.
1.
If other system componentsand connections check outokay, (a) replace pressureswitch if erratic fan operationis associated with airconditioning at idle or (b)replace fan temp switch if theerratic operation occursprimarily when the engine ishot.
2.
Fan cycles frequently whenengine is hot.
The fan should remain engaged long enoughto reduce temperature 7−10єF. The fan tempswitch is defective if the fan disengages afteronly a 3−4єF reduction.
Replace fan temp switch.
Troubleshooting 12−FAN CLUTCHES
12 − 63
Normally Open Fan Clutches
Problem Possible Cause Solution
Fan cycles frequently whenvehicle is stationary with A/CON.
Up to 4 cycles per minute is a normal conditionfor conventional control systems; turn off airconditioning system and cycling should stop.
To reduce cycling by up to 90%, installan Index K7 fan control system.
Fan turns on wheneverignition is on (turns off whenengine gets hot).
Air solenoid valve plumbed backwards. Check solenoid installation instructions;plumb correctly.
Control system fuses blown.If fuse blows whenever the ignition isturned on, the problem is most likelyrelated to a fault in the wiring.
1.
If the fuses blow only when the fanengages, the fault is probablyassociated with the solenoid valve.
2.
Check wiring, fix wherenecessary.
1.
Use an ohmmeter to check fora shorted solenoid coil (thecoil resistance should begreater than 14 ohms). Ifshorted, replace air solenoidvalve.