Re: 715 Alternator Rebuild Project Series
Post by adk4x4 on Oct 4, 2006, 11:22am

Rectifier basics will be the focus of the first installments of the this series.

The recitifier of the 715 alt is located mid section marked by cooling fins and the inability to remove them without complete disassembly. As shown in the manuals, two banks exist A, B or Pos, Neg. The rectifier is the simplest part of the alt and the easiest to test. This can be done with only removal of the back cover.

Using a multimeter on diode test setting test across each diode. Open circuit in only one direction Best to remove the diode lead from the alt. Test the positive recitifier for discontinuity to the frame as well.

Each bank consists of a heat sink/mount and three diodes. The diodes are 1/2" press fit automotive diodes.
Cross reference # 1N3943 pos and neg anode or NTN5962 pos and neg anode, 25 amp and 400v ratings.

here's a close up of both banks removed and diodes removed, note the rubber gasket/insulator be careful not to damage.



Please note the positive bank is coated with epoxy and removal of the diodes may damage this coating and should be touched up.
The wire tails have to be resoldered and this should be done while the diode is in the heatsink for stability and heat shedding.
The next post will show the newly installed diodes.