1990 Accord charging problem

Have a 1990 Accord EX 210,000 mi. Battery light came on, took battery
and alternator to A-Z for check, Battery was bad, alternator said
good. Put in new battery and battery light came on a few miles later.
Battery voltage 12.54 with car off, 12.28 when running. Replaced
alternator, same results. Looks like alternator is not kicking on for
some reason? HELP?

 

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Too bad you swapped the alternator. Usually you can just slip in a new
set of brushes into a Honda alternator without even removing the unit.
They probably charged a ton of labor to get that sucker out, right?
Now it's hard to know if the 'new' alternator is the real problem. Do
you suspect they don't have a clue?

'Curly'

 

I replaced the alternator, it wasn't really that hard. AutoZone did
check the original and said that it was good so I stuck it back in
along with a new battery. When the battery light came back on I
figured that maybe the alternator was intermittently bad??? because
there was only 12.5 volts. So I replace it. Light is still on and new
alternator doesn't seem to be charging either.
Dash Fuse #2 is good.
Alt plug black/yellow wire to ground with ignition on shows 12.5v,
also green/white to ground
Battery light not on with alt plug disconnected
Battery light comes on when jumper white/blue wire to ground

I must be overlooking something simple??

 

That can happen. Mine was intermittantly bad for several months
before I had time to deal with it. I would tap it with a stick to
"reseat" the brushes.


because

I got a tech sheet with my new Alternator. Said if you just changed
the alternator and it is still not charging the ELECTRIC LOAD DETECTOR
may be looking for and electrical load before the ECU will allow the
alternator to turn on; it does this through the C terminal.

Says with the engine running at fast idle, turn the headlights on for
30 seconds, turn them off and proceed with a standard charging system
test. WIth all accessories off, if the charging system still fails to
reach at least 13 volts with the engine at fast idle, shut engine off.
Remove 'C" terminal from the 4 pin alternator plug by releasing the
locking tab with a thin screwdriver Reinstall the plug. If the
systems now charges normally, the ECU or the ELD may be defective.
Consult a qualified technician.

"C" wire is white/yellow, by the way.

verbatim from my tech tip sheet that came with my alternator.

Hope this helps

Frank

 

depends on the alternator - on the civics, the mitsubishi brushes are
not replaceable.

 

Just tried that and still does not charge! Where is the ELD anyway?

Thanks for the info.
Mark

 

ELD unit is located in the relay box on the passenger side, engine
comprartment. Has a three pin connector on it (black, grn/red,
blk/yel)

Disconnect the connector, turn the ignition on, check for voltage
between blk/yel and black. If not look for an open or poor ground.

if there is voltage check for voltage between grn/red terminal and
the body ground. should see approximately 5 volts. If not check for
a code 20 on the ECU self diagnostic and go through the trouble
shooting flow chart.

If there is voltage recconect the 3 pin to the ELD. Check for voltage
between the GRN/RED terminal and the body ground with the ignition
switch on and the headlights on low beam. Should be approximately 2
volts.

If not replace relay box, ELD not available separately

If voltage as specified, ELD is OK.

From factory manual

Frank

 

| I must be overlooking something simple??

Yes, a *, took me a few hours to find & mitigate.
www.aa1car.com/library/charging_checks.htm

 

Mitigate what?

 

evidence of sanity.