Need help with 96 Legacy electrical problem.

[FroggyStyle]

I have a 1996 (or 1995.5 depending on how you look at it) Subaru Legacy L
FWD sedan with a (I believe) 1.8L H4. I replaced the battery about 3
months ago and have started noticing little problems ever since untill it
just died.
The small problems include:
-The needles on the Speedo and Tach would either drop to zero or remain
motionless under acceleration when the head lights were on.
-Fuse for the cig lighter/power mirrors kep blowing
-Car was difficult to start.

Last month while driving all the lighting (dash, headlights, etc.) began
to dim out until the car died just like the alternator was going out.
After the car died I was able to restart it and make it home without a
problem. When I got home I popped the hood and noticed the neg wire to
the battery was loose, I attempted to tighten it down but it was as tight
as it could go and was still loose. Attempted to start the next day but
had no power what-so-ever. Charged the battery and car fired right up but
then died again about 20 minutes later in the driveway. My question is
does this sound like a problem with the battery (neg wire does not fit
post), a problem with the alternator, or both (ie. the bad battery wore
out the alternator. Any help would be greatly apreciated.

 

[Remco]

I have a 1996 (or 1995.5 depending on how you look at it) Subaru Legacy L
FWD sedan with a (I believe) 1.8L H4. I replaced the battery about 3
months ago and have started noticing little problems ever since untill it
just died.
The small problems include:
-The needles on the Speedo and Tach would either drop to zero or remain
motionless under acceleration when the head lights were on.
-Fuse for the cig lighter/power mirrors kep blowing
-Car was difficult to start.

Last month while driving all the lighting (dash, headlights, etc.) began
to dim out until the car died just like the alternator was going out.
After the car died I was able to restart it and make it home without a
problem. When I got home I popped the hood and noticed the neg wire to
the battery was loose, I attempted to tighten it down but it was as tight
as it could go and was still loose. Attempted to start the next day but
had no power what-so-ever. Charged the battery and car fired right up but
then died again about 20 minutes later in the driveway. My question is
does this sound like a problem with the battery (neg wire does not fit
post), a problem with the alternator, or both (ie. the bad battery wore
out the alternator. Any help would be greatly apreciated.

I'd replace the terminal to the battery -- that contact should be
absolutely solid.

A battery acts as a filter to the voltage being generated by the
alternator. An alternator generates a voltage that varies wildly - the
battery smooths that out.
You can do damage to components on your car because the 12V supply
rails may have varied beyond the point where it is safe for some
components.
Most components have a voltage rating, specifying what they can take on
a constant basis and what they can take on a periodic basis. If those
ratings are exceeded - as would be the case with the battery out of
circuit - you can do damage or 'age' that component. It can potentially
affect all components like the alternator, ignitor, ECU, sensors, fuel
pump, etc.

Be sure to replace the terminal to the battery with a well fitting one.
Charge your battery and retry again. Measure the voltage across your
battery with the car running - it should be about 14.5 V.
Report back with your findings.

 

[Carl 1 Lucky Texan]

I'd replace the terminal to the battery -- that contact should be
absolutely solid.

A battery acts as a filter to the voltage being generated by the
alternator. An alternator generates a voltage that varies wildly - the
battery smooths that out.
You can do damage to components on your car because the 12V supply
rails may have varied beyond the point where it is safe for some
components.
Most components have a voltage rating, specifying what they can take on
a constant basis and what they can take on a periodic basis. If those
ratings are exceeded - as would be the case with the battery out of
circuit - you can do damage or 'age' that component. It can potentially
affect all components like the alternator, ignitor, ECU, sensors, fuel
pump, etc.

Be sure to replace the terminal to the battery with a well fitting one.
Charge your battery and retry again. Measure the voltage across your
battery with the car running - it should be about 14.5 V.
Report back with your findings.

What he said plus, while you're under there, check and retighten ALL
the ground (connected to the neg. side of the battery through varuious
wires and often connected to fenders, block, etc.) connections you can
find. Particularly important if you live in a rust/corrosion prone area.

carl

 

[S]

Hi Chris!

My question is
does this sound like a problem with the battery (neg wire does not fit
post), a problem with the alternator, or both (ie. the bad battery wore
out the alternator. Any help would be greatly apreciated.

The symptoms you describe could, I guess, all be attributed to a loose
connection at the battery, or a bad battery cable, or even poor
contact at the other end; starter/alternator/fuse box/chassis and
engine grounds . . .
Whatever, the cars electrical connections _ALL_ need to be clean and
tight for the various systems to function properly. Time spent
verifying and correcting little things like this is well spent IMO. If
you still have problems afterwards then at the very least you will
have eliminated several possible culprits. Have at it!

ByeBye! S.

Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101