Re: '86 C-GT Alternator repair?/short in system? (long)

[Huw Powell <human@nh.ultranet.com>]

-- [ From: Huw Powell * EMC.Ver #3.1a ] --

>I have a discharged battery and it will not hold a charge. I_can_jump the
car and the engine_will_idle and rev showing no_battery_idiot_light and
showing a_reading_of_13 on the digital volt display. But after shutting down
, it will not re-start.So battery is very low and does not hold a charge.
Alt.?

Your alt is ok - it's generating 13 volts at least.  Your battery is toast.

>The alternator is a remanufactured Bosch(90 amp?) that is 18 months old and
has 100K miles on it. Is there supposed to be a braided ground wire
connected to the alt. on Coupe GTs?...because mine doesn't have one.

It's grounded by its mounting bolts.

>Are there supposed to be any wires connected to the regulator when it is
pulled out? Mine didn't have any. 

No.  its connections are the brushes and, again, its mounting bolts.

>The voltage regulator looks corroded and could be worn but with regards to
regulators, I don't know what's worn and what's not. The brushes seem long
enough and seem fine, but I don't know about that either.

The brushes are over 1/2" long when new.  they'll _work_ until they're gone,
but since they are cheap I figure one might as well replace them while
they're out if there's less than 1/4" left.

>I read that the regulators are not replaceable in the Bosch 90 amp alt.s,
is that true? If so, should I try to get one from a junkyard?

Thought they were, part of the brush assembly... I may be wrong.

>my 'Autobahn' battery(550 CCA) is under two years old. Is it possible that
this battery could be bad now(drained too low) since the problem has been
ongoing for several days?(no time to fix during week)

Measure the voltage at the battery terminals while the ngine is running.  If
it is greater than 12.6 your battery is shot and your alternator is at least
ok.  If it's not... more likely to be the alternator, it's belt, or wiring.

To test the battery independent of the rest of the system, disconnect it,
charge it for a few hours or overnight (not indoors) and then use a load
type tester on it (these are heavy filament heater type things, all garages
usually have them).
 
Hope this helps a bit.


Huw Powell
HUMAN Speakers
http://www.thebook.com/human-speakers