bsoto

Hey guys.... i had my alternator replaced about 2 weeks ago. last night my belt slipped and caused the light to come on. I had the alternator tested to make sure it didnt go bad but it passed. Either way they swapped it for me and i have installed the new reman back on and the light is still on...

any suggestions or ideas on what might be causing it not to turn off?
any way to override the light and turn it off?

Im about to go get it tested installed and see what readings it gets.

Be back shortly.

mikey1

if the battery light is on while the engine is running it can mean a variety of things....

the first thing to check would be to make sure the belt is tight and spinning the alt as it should....

next would be to make sure the alt bolts are done up TIGHT TO SPEC as these alts rely on the bolts/frame for a ground connection,

if all that fails chances are the alt is faulty, test the battery voltage with the engine running....what does it read?

bsoto

Just got it tested and yup bad alternator

Duralast is a POS autozone parts are usually faulty i'm told
so now i have to reswap it -___-

CraigW

iTrader: (1)

Now it has became more clear.....remans are a joke.

Make sure you get the alternator bolts tightened correctly when swapping.

ezone

They aren't successful because they sell high quality parts.....

bsoto

3rd alternator and the light is still on... what else can it be?

ezone

Take it back again, have it tested
Keep replacing junk alternators until you get a good one?

Have the new ones tested before you leave the store too

bsoto

I've gotten 3 all test good in the store but then fail to pass the voltage regulator test running.

I'm buying a used OEM alt tomorrow and putting it in let's see what happens.


Last time I buy autozone parts however.

ezone

Did you check the other stuff?
Fuses, and the wires that are supposed to have 12v on them?

Got other symptoms you didn't mention?

mikey1

test the battery voltage with the engine idling even if the battery light is on, what does it read?.....maybe the light is the problem, not your alternator

bsoto

Ive checked all fuses and all wires everything is good.
I get about 13.8V with the car running and battery gets 100% charge
Is 13.8v normal? i was told yes but ive read on other posts it should be at 14.2v?

I got another alternator today, a genuine honda one and still on!
I even just replaced my ELD and same thing. im not sure what else it can be

bsoto

13.8v

ezone

Any codes?

Cluster self test/fault check and sweep test passes? (charge light should blink during bulb test)

Unplug the 4 wire connector from the alt while it's running, does the charge light go out?

Battery voltage is found on blk/yel wire at the alt plug (key on)?

Other 3 wires of the alt plug have continuity between alt and PCM, and none are shorted to ground? (service manual and wiring diagram, volt/ohm meter)

ALL fuses checked and good in both fuse boxes? (the system uses the PCM, gauge cluster, and multiplex control units so all of them must work correctly)


Charging voltage should be between 13.5 and 15.1v and output 60A or more @2000 RPM.


Which of these tests does not pass?

bsoto

No Codes at all.

Will do the cluster/gauge test next and also will try disconnecting the 4wire plug running.. just started raining while i was doing it so came back inside.

But blk/ylw cable does have voltage.
checked almost every wire and ground none seem to be shorted.

All fuses in both boxes are good none are blown.
i even did a Parasitic Draw Test all checked out good

Voltage at idle with just my AC on is 14.2V now however. But once i turn my headlights on it drops back to 13.2-13.8V

If i rev it to 2000 RPM it jumps back on to 14.2-14.8V

but light stays on...

bsoto

My cluster / gauge / sweep test gave me an error

bsoto

Light stays on when i remove the 4 wire connector

ezone

Sounds like the alternator is not the cause of the light then.

What was the error in the gauge tests?

bsoto

That's all it said "error"

ezone

Ok so you got through entering the gauge cluster self tests, got into the beeper check, the indicator light blink checks, LCD odometer segment check.....

Did it make the gauge sweep test happen or did it stop there when the odometer displayed Error?


The cluster made it to the communication line check and the odometer reads Error, then my info says there is a problem in the communication line between the gauge assembly, the multiplex control unit, and the ECM


So the next step would be to check the PCM and do the multiplex control unit self tests.

Does the PCM have any codes in it?
Will the PCM even communicate with a code reader, or does the reader say "no communication" in some way?

Were there other strange electrical symptoms before the charge light came on?? Gauges acting or reading funny?


Recent timing belt, belt set, or alternator replacement?
Alt bolts were not tight? (this can and will burn out the PCM)

bsoto

This is exactly what is does...
[YOUTUBE]https://www.youtube.com/watch?v=zdf0pYyoMGo[/YOUTUBE]

How can i do the PCM & multiplex control unit self test?

Gauges were fine

Well like i said i swapped it a few times thinking i had a bad alternator but everything is put back on correctly

PCM does not have any codes and does communicate and test but doesn't come back with anything

ezone

Have you found a service manual for the car yet? That would be a lot easier than trying to type it all out. Start with mode 1 tests, and you will have to create a jumper wire to fit some terminals in the fusebox.

Did you go through both fuseboxes and check ALL fuses yet?

ezone

Another thought:

Disconnect the battery, both cables. Short the cables together for about 10 minutes, then reconnect it. See if that makes anything different.

It's like a major system reboot.

bsoto

You know what I just figured out...
That if I wait 20 seconds after I put the key in before I start the car, that the battery light goes off and if I start the car it idles all weird and my temp or rpm gauge won't work check engine light goes on and it won't connect to read it. Then if I turn it off then back on instantly it keeps the battery light on but every gauge works


Blown ECU?

ezone

Probably.....
And the #1 cause of a burned up PCM on these cars is loose alternator mounting bolts.

Again, make sure those bolts are tight.
IDK if the PCM can be saved or not, it may be too late.




Unplug the 4 wire connector from the alternator so it cannot charge at all.
Start the car, see if the dash still acts wrong.

bsoto

Been a long week for me lol... been up very late trying to figure things out.
I will try unplugging the 4 wire connector prior to starting now


ordering a new PCM also
whats a good price on a used one?

I believe i have part # 37820-PLR-A13 for it
does it have to be the same exact one? cause i looked on ebay and cant find an A13

and whats the average programming price?

CraigW

iTrader: (1)

The last #s can change with changes made to parts.

Latest #is A15 and replaces A14.

bsoto

Would it be okay to get a newer model one for example a A15?

I believe i just found one here locally at LKQ parts for $70
About to go look at it and see what part # it is

Bell Honda in town said they could program it for $130

So im looking at about $220-230 after taxes

CraigW

iTrader: (1)

HPN has red text saying the A15 is latest (with the A14# to the left)

Yes, A15 is the latest... but it is it OEM ??

OEM is pricey.

bsoto

Well its a used part so it should be OEM right?

CraigW

iTrader: (1)

Should be, it will be marked well.