i have a 91 CRX si and while driving the other day i noticed the battery light on the cluster light up...so i checked the battery and determined it was due for one soon so i put a new one in and still the battery light is on...so i unplugged the ecu for a while, plugged it in, and no luck...any suggestions...car statrs and drives fine...its jutst that light...

 

check your alternator. Most likely it is bad and not charging your battery, hence the light coming on.

 

Alternator, get a new one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EF8 ownz u &raquo;</TD></TR><TR><TD CLASS="quote">Alternator, get a new one.</TD></TR></TABLE>

 

most likely the belt but double check the belts tension if its loose that could be your problem too

 

Definately the alternator or a ground

 

Wait a minute here...

That light usually indicates a charging problem... First thing to do:

Get yourself a voltmeter. Measure voltage at the battery. Should be around 12.6V

then start your car and measure again at 2000 rpms. Must be over 14V.

Check wiring from the alternator to the battery for corrosion, loose connections, etc.

If nothing. Replace alternator.

fs

 

It coule be the alternator, but instead of just guessing why not do a few test to make sure it is.

Yeah it could be, but why not check it to make sure it is ?

TESTING
Voltage Test
Make sure the engine is OFF, and turn the headlights on for 15–20 seconds to remove any surface charge from the battery.
Using a DVOM set to volts DC, probe across the battery terminals.
Measure the battery voltage.
Write down the voltage reading and proceed to the next test.
No-Load Test
Connect a tachometer to the engine.
CAUTION
Ensure that the transmission is in Park and the emergency brake is set. Blocking a wheel is optional and an added safety measure.


Turn off all electrical loads (radio, blower motor, wipers, etc.)
Start the engine and increase engine speed to approximately 1500 rpm.
Measure the voltage reading at the battery with the engine holding a steady 1500 rpm. Voltage should have raised at least 0.5 volts, but no more than 2.5 volts.
If the voltage does not go up more than 0.5 volts, the alternator is not charging. If the voltage goes up more than 2.5 volts, the alternator is overcharging.
NOTE: Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Further testing, which is not covered by this book, will reveal the exact component failure. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.


If the voltage is within specifications, proceed to the next test.
Load Test
With the engine running, turn on the blower motor and the high beams ( or other electrical accessories to place a load on the charging system).
Increase and hold engine speed to 2000 rpm.
Measure the voltage reading at the battery.
The voltage should increase at least 0.5 volts from the voltage test. If the voltage does not meet specifications, the charging system is malfunctioning.
NOTE: Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Further testing, which is not covered by this book, will reveal the exact component failure. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.

 

thanks for the heads up!! besides the bs on H-Tech, sometimes the information we share is invaluable. My batt. light came on and you saved me a search. It went off, but I am gonna do this testing because my battery shows less than 12 volts with engine running and nothing else on. Again a big thank you for this info

 

There is a lot of b.s on h-t, you just need to know who knows there stuff and who just says replace this replace and maybe you will solve the problem.