wade623

The battery light came on earlier today and I can't figure out why I went to auto zone and had them check the battery and alternator and said both were good (also checked with multi meter) got new battery connector and put it in And Cleaned Alternator Connections And Some Other Various Connections Under The Hood Also Cleaned The gauge Connections just because. So I don't know what else would cause the light to come on so I need some suggestions. Also a few days before this just before starting when the key would be between run and start the tachometer would jump to between 700-1000 then go back down then work normally after it was started

Also I have an optima yellow top in it I thought that might of had something to do with it so I tried the battery that I had in it before still nothing don't know if it matters but I'm trying to put everything up that I have already tried so that there is a better Starting point For The thread

GolNat

iTrader: (7)

Well the light is an indication that your charging system (alternator) is not working properly. It may still pass autozone's test and be bad.

What voltage are you reading with the car running? Does the light go out if you rev the engine?

wade623

The meter said 14.3-14.5v while running and no the light stays on constantly no flickering or blinking
And how else would the alternator be checked it's not like I have extra money to buy a new one and not even be the problem

CraigW

iTrader: (1)

The driving of that indicator gets pretty involved. Gauge cluster, micu and ecm.

Your voltage should be 14.5 and drop at times from eld's control, you might make sure real quick that it does indeed drop.

wade623

I did notice the light will flicker very quickly around 3k rpm when letting off the throttle to shift

wade623

New update on thus all of a sudden the battery light turned off and now the cel is on and the tach and temp gage are not working and when I went to check the code the scanner said no connection so I have no idea what's going on now I think I might be screwed

CraigW

iTrader: (1)

^^^^ Inspect fuse #10 (7.5A) & fuse # 4 (10A) in under dash box.

wade623

Checked the fuses both were good

wade623

Nnn:
This is what it's doing now when it is started and if you listen there is a clicking noise coming from the dash it sounds like a relay but I'm not sure what it would be

Speedometer and gas still work just the tachometer and temp stop

ezone

Someone left the alternator bolts loose, now the PCM is about to be toast....If it's not already.

wade623

All the bolts are tight. And how would the bolts being loose cause that?

ezone

Ok then how about the grounds for the engine and trans?



FYI if the alternator isn't properly grounded, the system will seek ground through the voltage regulator wiring to the PCM. The PCM in turn "fries" from excessively high voltage.
No communication with the scanner is a huge indication it may be too late to save it.


http://www.underhoodservice.com/tech-tip-honda-engine-won-t-start-check-for-loose-alternator-bolts/

This link tells about the problem, but there can be many more symptoms than listed. Search the forums if you wish, there have been a ton of posts on this.

wade623

well everything is tight i was messing with it yesterday before this happened and the check engine light just came on all of a sudden so i really dont know what happened

ezone

Messing with what, specifically?

bsmiley

There are no coincidences!

wade623

cleaning and tightening connections like battery alternator grounds and some other stuff because i thought it might be just a dirty connection or something but nothing

ezone

This sounds like what you messed with after the alt light came on.


What were you doing BEFORE the alternator light came on?

Or maybe I misread....were you not doing anything prior to that?



The loose alt bolt problems usually happen when someone does a timing belt job and forgets to tighten the bolts. Or replaces belts, or the alt, or something like that.

wade623

i did not do anything for some time before the battery light came on then after i seen that it was on yesterday when i got back i cleaned and tightened any of the connections that might of had something to do with it then today while i was driving the battery light went off and the cel came on and the tach and temp gauges stopped working and the motor will not rev over 3000-3500

ezone

All this, plus the relays clicking behind the glovebox, and no communication with a scanner-- sounds to me like the PCM has failed and is in limp mode.

The most common cause of this is what I already mentioned.
(And an overcharging alternator is always a possibility, but you said the voltages were not out of line.)

It's very likely too late to save this PCM (based on your description, but there's always a chance it can still be saved too).....
Any replacement PCM will also be doomed to the same fate if you can't find and fix the root cause of the failure.

wade623

well that sounds like it is not worth fixing i think im going to sell this thing for whatever i can get and get something else because i hate this car