User Manual

II113B
Page 1 of 1
Diode/Heat Sink Assembly
Replacement Instructions
C. E. Niehoff & Co. • 2021 Lee Street • Evanston, IL 60202 Tech Services Hotline [phone]
To replace any of three diode module/
heat sink assemblies:
1. Removedriveendcoverplateandsavehardwarefor
 reassembly.
2. Removeandsavethehardwareattachingthedefec-
 tivediodemodule/heatsinkassembly.
3. Disconnectonlyenoughwiringattachedtodefective
 diode/heatsinkassemblytofacilitatereplacement.
4. RemovedefectiveDiode/heatsinkassembly.Clean
 awaydebrisorcorrosionfromhousingsurfaces
 beforeinstallingnewassembly.
5. Installnewdiode/heatsinkassemblyinproper
 location.SeeFigure1.Torqueheatsinkmounting
 screwsto11.3–13.5Nm/100–120lb.in.
6. Reconnectwiringremovedinstep2:
 a. Phaseleadtoeachdiodemoduleasshownin
  Figure1.Torqueto4Nm/35lb.in.
Phase lead attaches here under spacer;
brown harness lead attaches on top of spacer

Figure 1 – Diode/Heat Sink Assemblies
A8-122/A8-125/N7354
Diode/Heat Sink Assembly

B+ stud — B+ leads attached
to modules (3 places)

 b. ToB+studandtorquescrewto28-29Nm/
  21-22lb.ft.FromB+wireassemblytodiode
  moduleandtorquescrewsto4Nm/35lb.in.
 c. Fromregulatorharnesstomodulescrewsand
  torquescrewsto4Nm/35lb.in.
 d. Fromgreengroundwiretoheatsinkandtorque
  screwto11.3–13.5Nm/100–120lb.in.
7. CoatelectricalterminalswithDowCorning®1–2577
 LowVOCRTVcoatingorequivalent.Donotuse
 coatingcontainingaceticacid(vinegarsmell)on
 electricalcomponents.
8. UsingDMM(digitalmultimeter)setondiodetest,
 connectredleadtoB+teminalonalternatorand
 connectblackleadtoB–terminalonalternator.
 MetershouldreadOL(blocking).Reverseleads,
 metershouldreadlessthan0.8V(flow).Ifmeter
 readszeroineitherdirection,recheckwiring
 connectionsanddiodeorientation.
9. Reattachdriveendcoverplateandtorquehardware
 to5.1Nm/45lb.in.
A8-123/A8-126/N7352
Diode/Heat Sink Assembly

A8-123/A8-126/N7352
Diode/Heat Sink Assembly


Phase lead attaches here

Phase lead attaches here

Regulator harness