well this problem had once again started up on my 87 sport...

my 7 does this:
-the battery slowly drains when the car is running (not when its sitting)
-the redline buzzer buzzes at 4K
-it wont start under its own power (i have to jump it off with another car)
-if i floor it in neutral, it bogs down then revs up
-it backfires sometimes
-and it randomly does this!

the battery is new, but im going to test it
the alternator is new (and tested good)
i've checked the battery and alternator connections (good)
I've got new battery terminals that are on good and tight
I've checked all under-hood fuses
I'll check the little kick panel fuses soon

has anyone had this problem ever???

I NEED MY CAR TO WORK RIGHT!
PLEASE HELP ME!

 

Monitor the voltage if the battery while the car is running, if less then 13V your alternator isn't working properly. Although it might be tested "good" it can be bad... most test just spin and check to see voltage,... but you need to see if there is enough current generated, check with load on the alternator.

 

ok ok..
but how would i self test my alternator?
and what would make this randomly happen???

*the battery tested good also**

 

As I said, monitoring voltage while the car is running.. that would be the best way to check if your alternator is working. Voltage shouldn't drop below 13v.. unless maybe you have all your lights on at idle.. but anything over 2k rpms should give you 13-14V.

 

well if i jump it off using another running car,
it cranks and registers almost 14V

but when I disconnect the jumper cables,
it goes down below 12V (with no accessories on)

so the alternator is good without load
but faulty without load?

 

**edit**
and once I dissconect the jumper cables,
the voltage goes from 12 to almost 8 in around 5 minutes.

AND
this problem was happening at night randomly the past few weeks,
but the voltage dropped then from 13 to 9 in around an hour or 2

and just recently it's started doing this constantly
and has been draining this fast...

1 more thing- if i rev up to around 4k
there is still no change on the voltage gauge

 

dude sounds like there are a couple issues with your 7 that need to be dealt with. I think the voltage dropping would be a sure sign your alternator is shot, i thought when the car was running you should be seeing 14v. Also, night time is the most common time for elctrical problems/ low voltage, this is when the most of your accessories will be on(lights and such), this is how problems get going. Low voltage means that your fuel pump might not be receiving enough current to power itself fully and krrp fuel running to your motor, that could be bad when your trying to floor it..... could lead to a blown motor. Be careful driving it in this condition, please look into the charging system.

also backfiring could be a number of different things, could be related could be completely seperate, i don't know enough about your car to help anymore, leave more details like current mods, recent upgrades/replacements and such. good luck.

 

If it's a relatively new alternator it may have a bad regulator, i've read one member on here had to go through 3 or 4 new alternators to get a good one.

 

well i took the old alternator off and exchanged it for a new one :-)

and now its running great!
it reads 14 Volts with everything off,
12.5ish with the AC on, Lights on, brakes pushed, and stereo on.

thanks guys!
you saved me a lot of trouble!

 

Still bad.

Anytime the voltage is under 13.5 volts, the alt is not providing enough power to charge the battery.

Any time the voltage is at or below 12.6 volts, the car is running on the battery.

Where are you buying these crappy alts???

 

... autozone.

and just to say- those readings are with the car at idle.

When I drive around now with every accessory on it's barely under 13V

 

again, the car should never ever ever be under 13.5 volts with a properlly functioning alt.

When driving around it should be at 14.4 volts.

Normally with the lights on, and the brakes and the stereo at a mid-level, you should be at 14.4 volts even at idle with a new (less than 30K miles) alt.

Do you have an upgraded stereo system or some other major current draw issue???

 

I'm having the same problem with my freaking pathfinder right now.... take back the alt, get it tested (under load) at autozone.

I had a similar problem with another car a couple years back. I remember that the plug in the back of the alt wasn't sensing the voltage correctly so the voltage reg wasn't starting the charge cycle... It would only barely trickle out voltage.. did the same thing yours is doing... and the same thing my pathfinder is doing...

Haven't figured out the pathfinder yet though... probably a bad alt.

Theoretically, if you unplug the battery while the car is running, it should KEEP running... Even with all of the accessories on.

 

well it's read the same with the last 3 alternator's i've had on my FC

and, i've hooked up a new stereo and put a system in
but i disconnected everything and double checked my wiring

and even with that all disconnected it still reads the same
so im positive those aren't causing this.


but maybe the alt isnt giving enough power period...
like maybe i should upgrade to a FD alt

would that be a direct bolt on?

 

If you disconnect everything so that your stock components are the onl thing in the system and it still isn't doing it.... an upgraded alt isn't what you need.. You have a problem you need to fix first.

 

a problem... that helps! lol

and someone told me I need a capacitor,
cuz if everything is on high and the bass hits hard,
everything barely dims

(but thats only at idle)

every reading is like it should be when im driving.

 

with the stereo off, do you have the same problems???

If so, you have a bad alt.

If not, you have too big of a stereo for the alt, and you need to upgrade the alt and battery.

A capacitor will only help if the lights are dimming (and even then only a minor amount) when the bass hits. It will not help anything else.

 

Does your car also have an electric fan? Hmm... Also, would the voltage differ between NA/ T2 and S4/ S5? Aaron Kake (sp?) where are you?

 

I hate hearing "somebody told me to X". Where X == "Something stupid".

A capacitor would be a GREAT thing to add.... if you were pumping out 1000watts of audio power...... However, it is NOT a fix for this problem.

 

Ok this is what is wrong with my car. Runs, turn on accessories, voltage drops to about 12 - 12.5 volts(like your car) if i disconnect the positive terminal while the car is running(the battery terminal) and reconnect it, it reads 14+ volts constantly regardless of what accesories are on(besides the defrost of course) so, I have no idea what is wrong, but my dad has had an autozone alternator catch fire on him before, and from what i hear from him and everyone he works with, autozone alternators are ****.

 

yeah im gonna hafta ask you to go ahead and buy a not-autozone alternator, that'd be great

those autozone people dont know wtf they are doing

btw, be grateful you arent having this problem in a saab it took myself and my mechanically inclined friend 4 hours to get that alternator out

 

My friends integra is behind the engine like, under the brake MC and everything, and he needs a new one. FCs are so easy to work on compared to alot of cars.

 

The capacitor thing wasn't someone's opinion,
they just told me that I needed one if
I'm going to be using that much power (200W stereo and 760W amp)

and i know that's just a fix for the bass problem...

but now when I look at the gauges more closley,
the Voltage is staying about 14 all the time when Im driving

At idle with the lights on and the brakes pushed it reads barely below 14...

so I think I'm just gonna stick with it.
Please dont hound me... Im just happy the car's running right

Until it fails on me again, I'll let it be.
Thats for all the help guys

 

Here's a fairly simple mod for you to help improve things: http://www.rotaryresurrection.com/2n...st_ground.html