No charge, no speedo

Hi, I'm new to the group, but my daughter has a Honda now so I'll be
lurking.
I didn't find anything on this exact problem in a search so:

Vehicle is a 1998 Civic DX 5spd.

Dead battery prompted a test of the alternator, which wasn't charging at
all.
Replaced alternator, and externally charged battery overnight. The car
started fine the next morning, and it worked fine for about 1/2 a day,
charging between 13.8v and 14.2v, then the speedo quit working, then that
evening the headlights were dim.

Next morning, battery was weak again, I charged the battery for a while,
then started it, but now there is a no charge condition again, verified with
a Fluke meter at the battery, but not at the alternator.

A brief check of the fuse block under the dash revealed a blown 10A fuse,
Alternator / Speedo. Replaced it, had a charge at the battery, then blew the
fuse when moving the vehicle in the driveway.

I suspect the vehicle speed sensor has a bad connection or is
malfunctioning. Any other ideas before I dive back in tomorrow?

Thanks in advance!

Spdloader

 

------------------------------------------
Disconnect the battery for 30 seconds, then reconnect without
'spitzensparken'. You might just need to clean up the 'boot' for all the
electronics. The don't like low voltages and errors creep in. Odyssey is
worst because many sliding doors and interior lights (and kids). Owners
spend hundreds on towing and 'diagnosis' when all they needed is a
recharge and a disconnect.

'Curly'

 

How did you test the alternator? Have you done a load test on the
battery? Check the connections on the alternator and the battery, make
sure your wired right and getting good connections. Make sure the
alternator belt is correctly tightened. These are the basics. If all
this is OK, and you the 30 second battery disconect and it still acts up,
I say you have a dead short somewhere in the system. You may have gotten
a bad alternator with a faulty voltage regulator.

Paul.

 

Thanks Curly, I gave it a try, but it didn't change anything.

Spdloader

 

I was a professional mechanic for 15 years, but haven't the experience with
Honda.

Original alternator tested and diagnosed with an AVR. Battery was properly
load tested.

Alternator was tested with a Fluke meter the second time.

I already covered the basics, but I appreciate the ideas.

The alternator is charging at the alternator, but not at the battery. That
rules out the alternator.

The alt/speedo fuse keeps blowing to prevent it from charging the battery,
which is why I suspect the VSS.

Spdloader

 

Hi Spdloader,

I've been lerking around this news group for almost a decade now and
just sold my 98 Civic Hatch to this a bodyshop guy who was going to
give it to her daughter (hope u're not the same). I'd hate to think the
car is being difficult, when it has been very good to me.

Anyways, you're the first person I've encountered that's having an
electrical short in the system for this model. If you're not making any
grounds, I'd recommend disconnecting any of the aftermarket stuff (if
any) and go from there.

Pars

 

Thanks, so far I've been unable to find anything amiss in the circuit, I
cleaned the VSS connection, cleaned the connections at the alternator again,
and cleaned the connections at the battery again. I have unwrapped the
wiring loom looking for a short, but have found nothing, after checking
about halfway up the line. I intend to finish up with that later today after
the outside temps go down. Too freakin' hot out right now to be leaning on a
metal car.

Oh, and this one's not a hatchback, it was a hand-me-down from her step dad.

Spdloader

 

With the fuse replaced, at idle, the new alternator charges 13.9v, as soon
as you rev the motor the tiniest bit, the alt/spd fuse blows.

I'm guessing, I've got yet another bad alternator.

Spdloader

 

You can get an inexpensive magnetic ammeter from many auto parts or tools
vendors. You just lay it over the wire, and it tells you how much current
is passing through it. I'm guessing bad alternator too.

Earle

 

Thanks Earle, the probe accessories on my Fluke meter allow me a similar
setup. Hard to believe three bad alternators with exactly the same problem.
1, the original, 2, the one from the salvage yard, and 3, the reman unit
from the Zone.

Later,

Spdloader

 

I find that hard to believe as well - I'd start looking for either
another source of the current draw, or something else that may be
killing the alternators (probably with excessive current draw).

I missed the original thread, but have you tested and/or replaced the
battery? An internal short may be sucking the current. Maybe check for
a short in the alt-to-battery wire (rubbing against the block?)

Hmm, 13.9V is really too high for idle... you should normally see closer
to 12.5V at idle (<1000rpm), and 14-14.5V when revved up.

 

This is a no-frills car. No power windows locks or anything, just a stereo
and rear window defroster, which did have a blown fuse.

The battery was properly tested with an AVR, and the charge harness has been
dissected and nothing notable found. VSS removed, tested, cleaned, and
re-intstalled.

That was immediately after putting in a new fuse, and the alternator started
charging. It quickly about (1-1/2min) went down to the 12.5 range and
maintained it, but upon revving the engine, the charge went off the scale
and the fuse blew again, all in about 2 seconds. Charge started down the
scale then.

Spdloader

 

It really looks like the current alternator is not regulator it's full
speed
voltage output and the battery is kind enough to mop up the extra amps
until the Fuse get bored and decides it's time to leave.

 

It really looks like the current alternator is not regulatING it's full
speed voltage output and the battery is kind enough to mop up
the extra amps until the Fuse gets bored and decides it's time to
leave.

Sorry for the typo.

 

This looks like problems with the voltage regulator. I am not sure where it
is located in a "1998 Civic DX 5spd", and I hope I never find out, because
mine is a 1999 HX, probably in the same place!

Earle

 

You know what sucks the worst, Earle? She gave up the '90 XJ Limited I gave
her for this thing. It never gave a moments trouble, just liked the gas.

Spdloader

 

Strange... if there was a short to ground somewhere, the voltage should
plummet just before the fuse blows. Does it still do it with the
battery disconnected?

It sounds like a bad voltage regulator, but that should be internal on
those alternators and so you'd be getting a different one with every
replacement alt.

 

If I'm not mistaken, the regulator is internal to the alternator, which
makes it that much stranger that this should happen with three different
alts.

 

Makes no difference if the battery is connected. Same outcome.

Tomorrow, it's a new alternator.

Update to follow.

Spdloader

 

Well, if it's not the battery mopping up all the amps til the fuse pops,
then it must be a short to ground.

Have you tried it with the high current stuff (headlights etc) on and
then measure the volts as the revs are raised?

Waiting with baited breath.