My DD 87 Accord Lx-i just had a battery light come on, then the pgm-fi light, then it shut down while driving.

My question is do we think it is the alternator or the battery, battery would be better, but 10 minutes before it died, I started it up, saw the light, shut it down, started it up listening for a slow cranking, it may have been slower than normal, but about as fast as my civic usually cranks (H22 11.2:1 comp w/ optima red top) then it fired up, i drove about 1 mile, waited in a spot for 5 minutes, the pgm-fi light came on, then I drove about 1/4 mile and it just shut down.

The alternator and battery were replaced about 2 years ago, but I don't know what it is that is causing this.

One thing weird with my elec. system is that we installed an alarm for keyless about 5-6 years ago, then took it out, and since we took it out the batt will only stay charged for about 2 weeks if the car isnt being driven. It seems to have caused a slooow electrical leak.

Other than this, the car performs flawlessly.

Any Ideas?
Sould I take my battery to AutoZone and have them test it?
I'm at school so I can't replace the alternator right now

Thanks,
MIKE

 

bump for all day

 

I hate to tell you this but it is prob the alternator. Remember all the battery does is start the car after that it is up to the alternator to run the car. If the alternator dies the batter will run it for a little while unit the battery runs out of current.

 

Try the 'caveman' test on the alt. get the battery charged up and start the car; Then thump the Alt a few times to see if the Alt light goes out. if the light goes out you can probably just replace the brush pak in the Alt. The dealers sell those brush paks for around $27, and they are easy to replace by removing the back of the Alt.[8mm-10mm nuts & a GOOD phillips tip] be sure to unhook the battery before doing any Alt. work

 

Most likely culprit is the alternator. Take your car to a batteryplus or autozone and have them run a quick test for you.

 

Both accord917 and lookingforvtec are correct; just by the discription of your failure.
First the alternator failed (set the"Battery" lamp), you comtinued to drive on battery reserve voltage until you hit the PFI computers' voltage threshhold (PFI light) then it shut off.
Hondadudes' suggested test is refreshingly cromagnon, but surprisingly useful, although a digital volt/ohm meter might be considered a little more elegant.

P

 

what kind of resistance should the alternator show, i have a multimeter, but don't know where to test.

For now I'm going to swap in a friend's battery and check the voltage over time to see if it drops.

thanks

MIKE

 

An alternator is traditionally tested by it's output (Volt meter). If you were to test the internals you could check the rotor and stator ring for an open circuit (infinity on an Ohm Meter), but you're getting too involved.
What you're really looking for is 12.3 to 12.6 volts from the battery with the engine off. With the engine running, a correctly adjusted belt and a good alternator (Dynamo to our friends in Norway), you should see anything from 13.8 to 14.4 volts (APROXIMATELY) at the battery.
Under heavy load conditions those 'running engine voltages' can drop, but not by much.
Anything much less that these values should prompt a trip to the local parts emporium.

P

 

the car started this afternoon, and I got 11.1V then it dropped a .01 every couple seconds.

I tapped the alt as hard as I could (its in the back all hidden-like) and nothing changed.

I guess i'll have to see if it was under warranty...

 

P_Adams could you please explain to me how touching the battery leads with a voltmeter will jog loose a stuck brush inside the Alt?? I've done this method HUNDREDS of times to prove the brushes are worn down and thay are not making good contact on the armature. Perhaps someday in your life you'll see the inside of a honda Alt, but in the mean time consider that I'm trying to help the person find and fix the problem. Throwing parts at problems is a **** poor method of diagnosis.

 

Hey, It would seem that no matter how I agree with someone [QUOTE] "Hondadudes' suggested test is refreshingly cromagnon, <U>but surprisingly useful</U>" I get called on it.
A volt meter test (and you know that's what I ment!) is a quick test if the Alternators' working. Ever test an Alternator with a screwdriver?
For GOD's sake "dude lighten up, I was reacting to the vision of some guy wacking away with a mallet.

 

put in a good batt, put a volt meter on the pos and neg post, un-do the plug on the back of the alt ( voltage regulator) when running, look for a change in voltage, when you un-plug it, the running voltage of 12 to 14 volts should drop, then when you plug it back in the voltage should go back up because its charging, if no change and it just keeps droping, replace you alt, make sure to charge you batt befor just starting up because charging a dead batt by just the alt is hard on both of them. good luck

 

If you read 11.1 at the battery then it has a shorted cell. I'm not saying that you don't have a bad alternator or something hooked up wrong that is causing your battery to pull down, but if your post connections are good then take the ground loose and read the battery again. if it is 11.7 or below then kiss it goodbye. most charged batteries will read about 12.7. one that is just clicking will read between 12.1 and 12.3 . Lead acid batteries like to stay charged and will short a cell if discharged to far.