4ks alternator problem (still)

[marriott@Summa4.COM]

Hellloooo everyone,

I finally had a "chance" to look at the wife's alternator last night, after 
she had to get a jump to come home from work! OOPS!! =8-(

'86 4ks

My original post
*************************************
howdy,
here's an interesting situation:
1. start the car, the alternator doesn't "come up." rev the engine once to 
1800 or better and the alternator comes up and stays up until you shut off 
the car. has no trouble maintaining voltage under full electrical load 
(once it's "initiated"). temp light flashes, batt and brake light are 
illuminated.
2. start car, no alternator. shift into reverse (rev lights on), alternator 
comes up (at idle this time) and idiot lights go out and stay out _while 
still in reverse_. shift out of reverse, idiots come back on, alternator 
stays up until car is shut off.

any ideas? bad ground (where), bad diode (where), bad reg, 
fuse/link/circuit breaker.
*************************************

Some updates:
1. Opposite to my earlier posts, the alternator is a Bosch. Couldn't match 
it to "big" or "little" from the outside by comparing to the Bentley.

2. The blue wire (approx. 16 guage) never has a voltage or draws any 
current. Engine off, starting, running, under load, never.

3. Bentley shows the blue wire going to the oil-buzzer control box. This 
box has been bypassed for six months due to intermittent buzzing with +5 
bar (verified by mechanical guage) oil pressure and new senders. Might the 
problem be with the box? What is it's physical location and is it the same 
box as my '87 4kcsq?

4. Jumpering to the "blue" terminal results in a 3.11 A continuous draw and 
instant alternator startup. Idiot lights go out. Reverse lights come on. 
Alternator light DOES NOT come on if I loosen the belt while it's running. 
I would guess the temp light wouldn't come on during overheating either. 
I'm driving the car today like this with the reverse bulbs pulled out (and 
watching temp guage ;-).

5. Brushes are fairly new. I checked them and they're fine. Problem seems 
to be with the harness somewhere . . .

6. Without the blue wire jumper (idiots flashing steadily), heavy 
acceleration (like dropping it out of a plane or flooring it in first) 
causes the lights to dim or even go out momentarily.

Any ideas would be appreciated, lest I have to repair it with a "for sale" 
sign and create a new customer for Autobahn01 ;-)

tia
James
 


James Marriott, BSME
work:  Manchester, NH, USA  marriott@Summa4.COM (603)625-4050 x 2539
home:  Auburn, NH, USA      marriott@grolen.com (603)483-8587

'64 Falcon Sprint Convertible--balanced & blueprinted 260 V-8
    GOES great. Stopping? 217k
'86 4000S        the better half's commuter (heated seats), 100k+
'87 4000CSQ      H-stock auto-x und daily driver, Kanc-1 veteran, 137k

If ignorance is bliss, then I'm          _____
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