1995 concord not charging battery

Diagram:
http://www.fortunecity.com/silverstone/chrysler/45/moparpost70.gif

Again, the two field posts on the back of the alternator are
interchangeable. It does not matter which one gets which wire.

DS

 

sorry but that link is not working

 

Before doing that I have a suggestion - you have a bad ground.

What I suspect is happening is that the computer's ground is at a different
voltage level than the ground of the alternator and/or the battery. If
there
is a resistance between the computer ground and the battery/alternator
ground it will make the computer think that the alternator output is lower
than it really is, thus the computer will try to correct this by raising the
charging voltage.

An external regulator will of course do the same thing if it's grounded
where
the computer is.

check all grounds from battery to frame, alternator to engine, engine to
frame,
and computer to frame.

Ted

 

No problem, I just didn't want others replying as if I had
actually said that...

 

[snip]

I think mounting the external regulator at this point is a
bit premature...

As a rule, fuses (fuse links also) do not blow because there
is a higher voltage on the circuit, they blow because the
amperage in the circuit has exceeded the rating of the fuse
device.
IOWs, there is very good reason to suspect that there is a
short to ground somewhere downstream of the blown fuse link.

Joust, you need to examine the wiring harness as it exits
where the fuse link was installed, follow the direction
where the wiring goes and start examining the harness for
where it may have rubbed thru and is now contacting the
frame/chassis/body of the vehicle.
If time permits, I'll pull up a wiring diagram and see what
hints I can glean from it.

It would also be worthwhile to replace that 30 amp fuse, and
if you can, connect your voltmeter to the battery or
alternator output stud and in the 30 seconds before the fuse
blows, check to see what the charging system voltage really
is with the circuit intact. (verify that the PCM has control
of the alternator)

It would also help to know the color code of the blown fuse
link and for shits and grins, the wire gauge of the blown
fuse link, (verify that a 30 amp fuse is sufficient for that
circuit) because frankly, if this -is- the alternator output
to battery circuit, 30 amps sounds pretty small.

 

Neil

Thanks for the info.

I agree with you.

When I had the 30 amp fuse in the voltage was 14.85 volts. Until it blew the
fuse then the alternator side went back up to 40vdc. I suspect that the
battery was clamping it down and drawing the 30 amps but my understanding of
this system is limited.

I was planning on tracing the fusible link wire completely.

The car ran for quite a long time on the battery alone while driving it to
the dealer. If a short exists to frame then I would expect that the battery
would drain very quickly or the alternator would burn out depending on what
side of the fusible link is shorted. I will through due diligence, check.

The wire coming off the alternator to the power distribution center is
black. It looks to me about 8 gauge buy don't quote me on that. No telling
what the fusible part is.

As to the 30 A fuse rating.... My thoughts were that the battery was fully
charged when I tried this test. No accessories were turned on. The Daytime
running lights were on by design (can't turn them off in Canada). It
occurred to me that 30a may not be sufficient but I have my doubts.

I truly wish I have a descent wing diagram of this car. If anybody has
access to a good one and a scanner I'd be truly and monetarily great full.


Barry

 

No surprise there, that alternator can put out a good solid 50-60 amps
at idle, and around 100 amps at full tilt. You need a true fusible link,
or a fuse rated at more like 110-120 amps.


Since the car is working fine otherwise, I suspect that yours blew for
some random reason (weak link to start with, bad connection at the link
causing it to overheat, etc.) I think you'll be fine once you get the
link in place, but it is POSSIBLE that it blew because your regulator is
indeed bad. The way to check this is to replace the link, CHARGE THE
BATTERY with a trickle charger so that the alternator won't be trying to
recharge a partially-drained battery, and then start the engine and
monitor the no-load battery voltage (ac off, lights off, everything
electrical off except that which is required to run the engine). If it
sails up over 15 volts in a few minutes and stays there, you probably
have a bad regulator. If it stabilizes between 13.5 and 14.something (I
forget the spec) you should be fine.

 

I just posted that I *doubt* there is a short any longer, but Neil's
suggested tests are a good idea. Its possible you had a wire rub right
at the fuse link, or an INTERMITTENT short that popped the link.

But I repeat, I have seen fuse links blow just because one end of them
was poorly soldered in-line, making it gradually get hotter until the
link pops there.

 

EXACTLY. That circuit can handle as much as 100 amps under NORMAL
operation, so a 30A fuse is indeed too small. It might work 90% of the
time, but the first time you partially drain the battery and then jump
in and fire it up, hit the AC, headlamps, and rear defogger, it WILL
blow

 

You guys are awesome
i will do.

I'm sick as a dog, had a very bad week and it is nice out. I'm diging in and
getting to the bottom of this problem TODAY.

if all fails i found the regulator i need for $50. And they have to order
the connector just as Daniel suspected.

Chrysler admitted that they cannot provide fusible links and have no idea
what the guys in the shop do to replace them (read in that they use a peice
of wire.)
i think I'll put a 100 amp fuse in there. I am uncomfortable with only a
straight wire.
1st thing i do now is to open the harness and get the fusible link out to
insepct it.
then look for shorts.
Barry

 

EEK! NO! It is *VERY* dangerous to replace fuselink wire with regular
wire. The fuselink is there for a very good reason. DO NOT defeat this
fuse protection!

Replacing a fuselink with a fuse can be done, but ONLY if you know exactly
what you're doing and select the correct type of fuse. It must be a
slow-blow fuse, not a regular one -- these are harder to find than
conventional fuses. It must also be of the correct amperage rating, which
requires knowing the output capacity of your alternator. Much better to
put in a replacement fuselink. It must be the same length as the original
fuselink, and the same gauge size. The gauge size will be marked on the
fuselink insulation. If it is not or it is illegible, the rule is that the
fuselink wire must be 4 gauge sizes smaller than the wire it is
protecting. If the wire being protected is a #10 wire, the fuselink must
be #18, for instance. Fuselink wire is fuselink wire, it is not regular
wire. NAPA will sell you Belden brand fuselink wire. If one of their
prefab, cut to length fuselinks is not suitable for your application,
they'll sell you the proper gauge fuselink wire on a spool, and you can
cut your own. Fuselinks must be soldered in place. Use heat shrink tubing
to cover the repair.

DS

 

EUREKA!!!
i found the problem.
while tracing the main wire, I found the fusable link wire. they had it
under the washer bottle and it was looped back on itself and tie wraped.
i guess they had nicked the insulation at one of the bends because it was
all green and at teh last there was only two strands or so left.

it was about 6 inches long and 2 inches are gone now.
i'm off to NAPA to get some...
Thanks for all the help.

 

Well, at least something went right today....

BTW, I checked the wiring diagram, that fuse link should be
a 12 ga.

 

All fixed.
Thanks to all who help me and put up with my sheer ignorance. I learned a
lot from you guys and about this car. This knowledge will be put to good use
later.
I'm glad it wasn't February when this happened.
I think i will install a voltmeter....