My car has been sitting for a while (5 months). The battery was dead. It's an Optima Yellow top deep cycle. I put it on a charger, and it charged up, with no problems. The car started and ran fine for a few days. However, it's been pretty cold lately, and that yellow top just doesn't seem to start my car after a day or two of driving. Even if I don't use any accessories (at least keep the heater on the first setting). If I put the battery on a charger over night, the car will start fine for at least a few days. The battery does not appear to be charging when I drive it tho... I've tried taking longer trips (30-40 minutes), but it never seems to charge up like it does under a charger.

Could this be an alternator issue? Do alternators go partially? If so, that may be what's happening. 2004 Acura TSX 6spd 135,000 miles.

Thanks!

 

I should also mention that the car does not seem to be without power; I can run all accessories without a problem while driving.

I've ready somewhere that some alternators have two diodes. One diode will blow, and it will allow for the car to continue to function relatively normally; however it might not charge your battery after a while..

When do 04 TSX Alternators go?

 

Use a digital voltmeter to measure the battery terminal voltage with the engine running and all accessories off. Voltage should be 13.8 to 14.2 after you have charged the battery with the 110 volt charger. Then turn all the lights and accessories on and measure the voltage - it should still be at 13.5 to 13.8 volts - lower but not by much. If those numbers are below 12.6 volts, it's a bad alternator. If the alternator looks OK, have Wally World check the battery (in the car).

 

new battery mate

 

As far as what I have seen with older Honda's the alternators usually just go and you end up with the battery light on (didn't mention it was on so I would assume it isn't). You should see how much fun it was to guess that it was this in my sister's old Hyundai Elantra (their alternators do flake on and off before they go completely). I would guess to say it is the battery. You do have close what my father had when his alternator went out so it may be next.

 

I am having a similar issue with my new alternator. The day I changed my alternator out, I've had voltage spikes from the alternator up to 18.3V down to 13.8V. No pattern from spikes. My lights will go off and on, stereo pops on and off. I'm going to the parts store I bought the alternator at, and having them check it. I think the internal voltage regulator is faulty in the alternator.....we'll see.

 

It was my alternator. All fixed.

 

I'm probably going to have that problem sooner or later. How much did it cost to get it fixed?

 

The only part I bought was a rebuilt alternator from O'Reilly's. Cost $120. Make sure you have them bench test it before you leave the store, too make sure it runs fine. My serpentine was replaced a year ago, so no cost there. I used this video:
The video is for a 2004 accord, but it has the same engine and setup as the '04 TSX.
My only recommendation is use a ratcheting wrench for the bottom two bolts, because of the space, using a socket wrench is not fun. Takes 30 minutes easy, no problems, just watch the connectors. Enjoy!