Battery Dead and Rough Idle
 

Hello guys, this past week I've had a dead battery every morning and had to jump-start my car to get it going. At first I found the glove compartment switch was broken which caused the light to stay on overnight. But now it keeps dying after I took out the bulb. Also, when I jump-start the engine gives me a rough idle, everything else works fine though, the windows work at normal rate and everything, however when I use anything electrical, the dash light dims. The battery is 1 year old. Another problem is the mpg use to mark 24.8 and lately its been going down to 23.4. What could this be?

To many problems in one thread.

If the battery is low is may be bad. Bad batteries can be a pain and yes a one year old battery can be bad. Take it to the auto parts store and have them test it. Don't tell them how old it is. Winter is the time that all weak batteries kick the bucket.

How far do you usually drive per day? Short trips can be the cause. A battery needs a good 30+ minutes every few days to stay charged up.

As for the gas mileage, if you are in a winter climate your mileage will be less. Cold weather uses more gas.

You sir are awesome, and yes these are just some of the few problems I have on the car. I usually drive about 30 minutes a day but due to vacations I barley have the car running. On occasions I drive up to the city and have the car running about 1 hour but that's only been once every two weeks. I was also suspecting if the alternator could be the cause?

If the car runs fine after you jump it the alternator is probably fine.

As for the rough idle, do you have a CEL? Maybe you need new plugs or coil packs. How many miles and what year is the car?

I changed the ignition coils a few months back but not the spark plugs the car is a 2000 with 160000 miles

Check the plugs. They may need to be replaced every 30,000 miles.

will do, I also read volvo plugs are the recommended plugs I put on them is this true?

Yes, that's all I use. NGK's run well in the 960's as well.

I would still check the alternator. If you have lights that are dimming it doesn't sound like it's putting out the rated amps. If you have an alternator/starter repair shop that would be my choice before a rebuilt from the chain stores. The regulator on the alternator seems to be the weak link.Low voltage will cause all kinds of running problems.