chuck04

While driving to work this morning, the dashboard & navigation displays suddenly started to turn on and off and the speedometer/fuel gauge dropped to zero... I drove to the nearest dealer, and they said the battery was dead and that alternator/charging system is okay. So they replaced the battery and sent me off.

But I now hear a whining sound coming from the engine (which was not there before) and when I measure the voltage across the battery, I'm getting ~12V with the car engine running. In other posts, folks are saying ~13-14V is right for a healthy alternator.

My guess is that the alternator is dying. But it seems 60K miles is a bit early for alternator failure...Has anyone have a similar experience with measuring their battery voltage when their TSX is running?

thanks!

dwest1023

If you are only getting 12 volts with the engine running, I would say you have a alternator problem for sure. You should see at least 13V.

Simba91102

Your alternator is dying a slow death. It does seem a bit premature, but it goes when it goes (is your car an 04?). You should get it replaced before it dies since your car won't run without it.

chuck04

thanks for the inputs.

I have an '04. The car was dying as I was driving, so I figured it was the alternator and not the battery. Too bad it's going bad at 60K..

The service rep said that they checked the charging system, and the battery was the problem. The tech's remark on the invoice was: "FOUND BATTERY FAILED LOAD TEST; REPLACED BATTERY"

So, I'll ask them again. Something isn't quite right, and I would't want to lose electrical power again on the road

ToeSeX05

Hey Chuck04, which dealer did you go to? I'm in the southbay myself.

nbtx

You should see 13.8 to 14.2 volts at the battery terminals above idle with no AC, lights, etc.
Two possibilities: alternator going bad, or they replaced your battery with a new one with a shorted cell (highly unlikely). The real question is why did they replace the battery - my guess is an incorrect diagnosis. Head back to the dealer and get a second opinion.

bignoodleboi

i say its the alternator I don't know why the dealership said it was your battery.. cause like other posted a healthy alternator running would be 13.2v-14.2v... and while if you crank it the battery should drop down to the lowest 10v.. and as you stated you stated your alternator reads 12v so its time for a new alternator :-)

Simba91102

You may want to bypass the dealer on this. Look for a shop (hopefully local) that specializes in electrical systems (check either on the web or the old fashioned yellow pages for "generators" or "automotive electrical" or the like) and try them out. An alternator test and refit is not a big job and they'd most likely provide the same warranty that a dealer would (and might be cheaper). Wonder why the dealer dropped the ball on this. They may have just performed a load test on the battery and found it below par and just went with that (not unlikely considering the reputation the OE batteries have) and not tested the complete charging system. A funky alternator may actually be responsible for the failure of the battery too (a long term low voltage condition for instance). Keep us informed (I've got an 05 with 65K miles).

chuck04

Thanks for the feedback! I checked the voltage again this morning, this time revving the engine past 2K RPM. The battery voltage rose to ~13.2V...higher than last night's 12.5V; I'm guessing it has to do with an alternator charging better when it's cold?

I also talked to the service rep, and he said that they tested the alternator. It was producing 80-90Amps. Checking on the internet, the TSX alternator is rated for 105Amps (max). I'm not sure if the 80-90Amps is right - it may depend on how the load on the alternator during testing; the service rep was trying to tell me that 80-90Amps is good because "producing too much amps could damage the car's electronics".

When I mentioned about the whining sound, he said he remembered hearing it. That convinced him it was worth a second look.

Anyhow, I am scheduled to come back in next week to get a new PC board for another issue (dim clock diplay/no radio lights); they said they'll run the charging test again. I'm thinking about getting the alternator checked/replaced at an independent shop, but am hoping there can be some "good will discount" for a new alternator (if that's the problem) since the car is barely under 60K miles.

Will keep you posted on how things turn out...

chuck04

Yup, it was a bad alternator. I had it replaced today at a local mechanic shop; I decided it wasn't worth going back to the place which dropped the ball on a dying alternator...

Now there's no more "whine" while driving, and the battery is charging at ~14V with all the electrical accessories turned on.

Thanks for everyone's help and inputs on this.

human668

How much did you pay?
I'm in Irvine CA. I bought my 04 TSX used. I hear the "whine" noise since day one.
I don't know if it's a bad alternator in my case but it's good to check though. Is pepboy a good shop to go?

chuck04

I'd suggest buying a voltmeter from your local electronics store (e.g. Radio Shack) and measuring the battery voltage with all your electrical accessories turned on (i.e. heater, defrost, radio, lights). If it's <13V, then your alternator is probably going out.

Prices vary - depending if you get a new or remanufactured alternator. I shopped around and got quotes from $500-600 for a new alternator + installation. It's an expensive thing to replace, so using a voltmeter to check things out first is a good idea... Good luck!

LukeaTron

I don't know what the Pepboys out in California are like but if they're anything like they are in PA, do not ever take your car there. My old room mate took his Celica there for inspection and the shady fucks pulled a bunch of vacuum hoses off then wanted to charge him $1000 to "fix" it. The car ran fine when it went in and obviously with the hoses off, ran like ass afterwards.

I guess they thought he was a stooge, which would have been correct, but being the gear head I am I was able to figure it out in about 5 minutes of looking under the hood. I reamed out the manager something fierce and he got his inspection for free. I will NEVER take anything to Pepboys again.

02AEMCL

ok i have a problem with my voltage, i have a voltmeter in my car to monitor voltage and what not, when i drive the voltage will drop to 12.2-12.5 but when i put the car in neutral the voltage goes up to 14.1-14.3, it will also go up to 14 while driving only if i have lights or ac on. whats the deal, i this only happens when its driving?

main70072

Sounds like a similar problem I have documented here for my TL: https://acurazine.com/forums/1g-tl-problems-fixes-118/alternator-703043/

According to the TexasHonda from the thread above, this appears to be normal in Hondas/Acuras because they have some kind of load detection circuit to reduce the charge voltage in order to save fuel. Nevertheless, check your connections on the alternator and battery for corrosion and/or tightness.