Last Friday on my way into work I notice the car seemed to turn over very slowly. Not surprised I've been thinking it's about time for a new battery. Later that evening I got into my car to come home from work and it was dead. I called and got a jump. I let it idle for a few minutes and then disconnected the negative to make sure the alternator was working so I wouldn't have any problems driving home. My headlights were on, my door was open so the interior light was on. As soon as I removed the negative cable the lights got extremely bright and then went dead. This was some kind of a voltage spike that blew out my interior light and headlights.

So I drive home with my high beams on. I replace the battery on Saturday. Again, I disconnect the cable to see what happens, this time with my headlights off. It blows my interior light again. Also, because my stereo was on, it seem to have blown the amp part of the stereo, it works (lights up and shows the station) but no sound.

Is this an indication of a bad alternator? I've never had this kind of problem with an alternator. As long as the battery cables are connected there are no spikes in voltage. I'm thinking the battery is absorbing it. My concern is that it is overcharging the battery and might cause a more serious problem with the battery being overcharged.

Also, any ideas on my stereo? It's the stock stereo, does it have an internal amp, or an external one somewhere else in the car?

Thanks,
Dan

 

you shouldnt have removed the negative cable. dont do it again

 

the easiest way to test it is to go down to your local autoparts store and they can just connect up your system to their tester... or put a volt meter on your battery when your car is running and check the voltage to see if it's abnormally high (like 20 volts or so....) As far as your stereo is concerned I'll bet it just blew a fuse... check under the dash and then in the engine bay and make sure all your fuses are okay first.

 

wow, you are going to spend big cash to fix all of the problems you just created with your car....good luck

 

Sounds like the voltage regulator took a crap.

 

And... that's also a real good reason why it's not a real good idea to disconnect the battery with the engine running. That was a reasonable poor-mans alternator test back in the '60s but you're probably lucky you didn't also burn up your ECU.

 

evil a couple of things.

# 1 why don't you let all of us know what year and model you need help on......depending on year and model honda had some issues with the wiring

# 2 as suggested by other members have the CHARGING system properly tested.. take it to a shop that specializes on Hondas or the Dealer

# 3 i guess you learned by experience that disconnecting the calbe while car is running could be hazardous to the car electrical system , for your sake i hope you do not try that again

# 4 is the battery lite on ??? is the rpm high at idle ???

 

I appreciate all the constructive input.

My Accord is a '97 LX 2.2. The vehicle is entirely stock, no goofy glow lights or other creative wiring. When I get a chance I'll have the charging system diagnosed. I replaced the alternator last year and from what I've been reading, rebuilds don't work very well. The battery light isn't on. With the new battery, the car is running perfectly fine, good idle (about 750 rpm), etc. I notice that while driving the dash lights are brighter with the new battery. It could be I just got used to them being dimmer with the old battery. I also notice when sitting idle the dash lights dim by about 30%. I'm assuming my problem is the alternator.

I should have mentioned that the radio fuse did blow when I disconnected the battery the second time last Saturday. After changing the fuse, the radio would light up and seem normal, but no sound. My guess is that the stereo is fried. I've checked all the other fuses and they're fine.

Thanks,
Dan

 

radio is almost certainly fried. amps blow fuses, voltage blows equipment