Charging System Problem

[Chris 007]

Hi everyone,
This is my very first post, on my very first day @ this forum :)

Looking for much needed expert advice on my van's electrical system. The alternator ( Denso) started to malfunction ( Became really hot & drained the battery), took it to an auto electrician. Armature, diode plate & regulator got replaced ( with brand new parts). Put it back in and still battery light won't light up in Dashboard. Can mail pics if in need to diagnose.
The repaired Alt. heats up a little, while draining the Batt. ( <0.25v ), when Ignition is off.

When only B+ is connected, no heat generated or batt. draining (Guess the Diode plate is ok.)

Recorded below readings with a digital multi-meter

When ignition is on
IG is ok, +12v
Sense wire +12v


when key is in Acc/off possition
IG is ok, 0v
Sense wire ~11v

Sense terminal on Alt. side is sinking ~9v, when ignition is on/off. Is this ok?

This is a Denso Alt. with 3 connectors & Batt. wire.

Thx in advance.

[Rufus]

Did you check the fuseable link by the battery?

[Chris 007]

Yeah. The charging, engine & IG fuses also checked. They are fine. The tech who installed security system, has installed a separate wire from Alt. light contact to dashboard batt. indicator light ( negative side) , disconnecting the original wire. Will be replacing that with a new wire, today, if time permits.

When IG is off (key in off position), IG wire which turns alt. on, is getting grounded. When a voltmeter is connected between + terminal of batt. & the Alt. end of IG wire , it has a reading of ~12v. Is this normal?

[Chris 007]

When IG is off, sense wire connector on Alt. is sinking ~10v. Is this normal? Shouldn't it be off?