Part # 130-068 -1- Revised 03/13

MG Midget & Austin-Healey Sprite Alternator Conversion

Installation Instructions Sprite/Midget '61-71, Morris Minor

PART #130-068 440 Rutherford St. Goleta, CA 93117

1-800-667-7872 • FAX 805-692-2525 • www.mossmotors.com

Tools required:• Mediumflatbladescrewdriver• Mediumphillipsscrewdriver• 1/2”wrench,7/16”wrench,5/16”wrench• 9/16”socket,1/2”socket• Dead-blowhammer• Airimpactgun• 22mmsocket• Prybar• Wirecutters,wirecrimpers• Pliers• Voltmeter

Note: The vehicle must be converted to negative ground before the alternator can be installed. These instructions will outline this polarity conversion as a part of the alternator conversion.

If your vehicle is Negative Ground, move on to “Alternator Installation”

Vehicle Preparation: Positive Ground to Negative Ground Conversion

1. Disconnectthebatteryusinga1/2”wrench.

2. DisconnecttheBrown/GreenandBrown/YellowwiresfromtheGenerator.Ifthegeneratorusesringtypeconnectorsusea5/16”anda7/16”wrench.

3. Reversethepositionsofthetwowiresontheignitioncoil.Note:Ifthevehicleusesanelectronicignitionitwillhavetobereplacedwithanegativegroundelectronicignition.WerecommendMossMotors#222-405.

4. Ifanammeterorvoltmeterhasbeenfittedthepositionofthesewireswillneedtobereversed.

5. Ifthefuelpumpissolidstateitwillhavetobereplaced.WerecommendMossMotors#377-285.

6. Ifthevehicleusesamechanicaltachometermoveontothenextstep.Ifthevehicleusesanelectronictachometeritwillneedtobeconverted.Toconvertthetachometer,JohnTwistoffersthefollowingadvice:

Twochangesarenecessarytocompletelyconvertyourearlypositivegroundelectrictach:

a.) Thewiresmustbereversedatthe“whitewireloop”atthebackoftheunit,andb.)thepowerandearthconnectionsmustbereversedinsidethecase.

a.)Thewireinthe“whitewireloop”comesfromthekeyswitchandtravelstothehotsideofthecoil.Referringtotheillustrationbelow,selectoneofthewiresandtagitwithtwopiecesoftapeforidentification.Then,cutthewirebetweenthepiecesoftape,andcuttheotherwiretothesamelength.Reversetheconnections(nowthereisonepieceoftapeoneachwire)andsolderthem(remember,thisisthepowerleadforthecoilandisunfused).Tapeuptheconnectionscarefully.Whenlaterreplacingtheplasticblockonthebackofthetach,ensurethatthemetalbandaroundtheblockiscarefullypositioned.Thisisanecessarypartoftheelectromagneticpickup.

b.)Toreversethepowerwireandearthwireinsidetheunit,itisnecessarytoremovethechromering,theglassfaceandtheglareshroud.Thechromeringisusuallyremovedwithgreatdifficultybypryingthetabswithasmallscrewdriver,thenrotatinguntilthetabscanfitthroughtheslotsinthecase.Removethetwoscrewsonthebackoftheunitthatholdtheinternalstothecase(not

Installation Instructions

Part # 130-068 -2- Revised 03/13

thetwowhoseheadsfitinholesinthecase),andallowthoseinternalstodropcarefullyintoyourhand.Don’tbendtheneedle!Thespadeterminalisthepowerconnection,justnexttothisistheearthconnection.Aresistorissolderedtooneoftheseconnections,andagreenwiretotheother.Unsoldertheendsofthegreenwireandtheresistorfromtheircurrentpositions.Re-solderthegreenwiretowheretheresistorwasconnected,andtheresistortowherethegreenwirewasconnected.Reassembletheunitaftercleaningtheglass.

Illustration 6

7. Swaptheconnectorsonthebatterycablesusinga7/16”wrench.Refitthebatterysothepositivecableisattachedtothepositive(+)sideofthebattery.Leavethenegative(-)groundcabledisconnecteduntiltheinstallationiscomplete.

Alternator Installation

1. Disconnectthebatteryusinga1/2”wrench.

2. DisconnecttheBrown/GreenandBrown/YellowwiresfromtheGenerator.Ifthegeneratorusesringtypeconnectorsusea5/16”anda7/16”wrench.

3. Loosenandremovethenutandlockwasheronthepillarblockusinga9/16”sockettoallowthegeneratortorotatedownandremovethedrivebelt.(Illustration 2)

Removetheadjustmentlinkfromthegeneratorusinga1/2”socket.

Illustration 2

4. Removethepivotboltsfromthewaterpumpearandtherearmountingbracketusinga1/2”wrenchand1/2”socket.

5. Removetherearbracketfromtheblockusinga1/2”socketandreplacewiththenewbracketsuppliedinthekit(Mosspartnumber130-115)usingthesamehardware.Donottightendownthebracketyet.

Illustration 5

6. Fitthealternatorwiththefanandpulleysuppliedinthekit.Itmayhelptoseatthepulleyagainstthefanbytappingtheouteredgesevenlywithadead-blowhammer.Thewoodruffkeyhasatendencytocomeoutduringthisprocess.Applypressuretothekeywithaflatbladescrewdrivertokeepitinplacewhiletappingthepulleyon.Makesurethatthefanbladespointtowardthealternator.Wrapashopragaroundthefanandholditfirmly,butinasafemannersothatitcanbereleasedwithoutdamagetothehandorfingers.Tightenthenutwithtwobrief(1sec.max.)triggerpullsonanairimpactgunusinga22mmsocket.Checkthatthefanisnotlooseandrepeatthetighteningofthenutifnecessary.AttachtheadjustmentlinkfromthegeneratortothealternatorrespectivetoitsoriginalpositionusingtheM8x1.25x20boltandlockwasherprovided.Donottightenthisboltyet.

7. Fitthealternatortotheenginebyfirstslidingthelongslotintheadjustmentlinkoverthethreadedstudonthepillarblock.Lineupthefront-mostmountingearwiththewaterpumpmountingearandinserttheoriginalboltwithoneoftheflatwashersprovided.Lineuptherearmostmountingearwiththenewalternatorbracketandinsertthe5/16-24boltprovided.Returnthepillarblocknutandlockwashertothepillarblock.Returnthenutandwashertothefrontmountingbolt

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Part # 130-068 -3- Revised 03/13

withtheaddedflatwasherbetweenthebacksideofthewaterpumpmountingearandthelockwasher.Returnthenutandlockwasherfromtheoriginalrearmountingbolttothenewmountingbolt.Leavethemountingboltssnugglytightened.Makesurethatthealternatorisatfulldroop. (See Illustration 7)

Illustration 7

Ifthewiresremovedfromthegeneratorarefittedwiththeringtypeconnectorsthenthefemalespadeconnectorswillhavetobeinstalled.Todoso,removetheringtypeconnectorswithwirecuttersandstrip1/4”ofinsulationoffofeachwire.Attachoneofthetwonon-coveredfemalespadeconnectorstotheBrown/YellowwireandasmallredspadeconnectortotheBrown/Greenwireusingwirecrimpers.Usea1”sectionoftheheatshrinkprovidedtocoverthelargerspadeconnector.

8. Fitthenewbeltbyfirstlocatingthecrankpulleywiththebottomofthebeltandthenwrappingitaroundthewaterpumppulleyandfinallywalkingthebeltontothealternatorpulley.Tightenthebeltusingashoptowelandaprybarwedgedinbetweenthealternatorandtheblock.Tightenthepillarblocknuttofixtheadjustmentlink.Thentightentheboltattachingthelinktothealternatorandthefrontmountingbolt.Nexttightentherearalternatormountingboltandthenthebracketmountingbolts.Theorderinwhichtheseboltsaretightenedisbeneficialtothefitmentofthenewmountingbracket.Checkthatthebeltdeflects3/16”-1/4”atthecenterofthebeltbetweenthewaterpumppulleyandthealternatorpulleyandadjustasneeded.

Illustration 8

9. Thefirstillustrationbelowshowsastocknegative(-)groundvehicle’swiringdiagramwiththegeneratorstillintact.Removeallthewiresfromthecontrolboxasshowinthesecondillustration.

Illustration 9

10.Plugthewiresintoyouralternatorasshown.

Illustration 10

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Part # 130-068 -4- Revised 03/13

11. Completethewiringonyourvehicleusingthefollowingdiagram.Makesuretoinsulatetheconnections.Youmayremovetheregulator(generatorcontrolbox),itisnolongerneeded.

Illustration 11

12.Turnthekeytotheonpositionanddonotstartit.Checkallofthemodifiedareasandinsurethatthereisnosparkingorsmoke.Nowstartthecarbringtosteadyidle.Attachavoltmetertothebatteryterminalsandverifythatthereadingisgreaterthan13volts.RevthecarupandverifythatthevoltagereadingincreaseswithRPM.

13. Installthenegative(ground)batterycabletothenegative(-)terminalofthebattery.

14.EnjoyyournewMossalternatorconversionkit!SeeMossMotors.comforallyourpartsandaccessories.