rbr

I having some voltage issues. The battery was slowly draining over the past couple of days. When I start the car it would start at about 13V and slowly go down to about 9 volts. I went to a parts store and they checked the alternator and they said it seemed to be working fine. So, I thought it must be the battery, so I replaced the battery; but, now I am still having issues. The battery stays at about 11V when the car is started. Just last night the battery indicator light came on. Also, the V-Belt seems to be fine.

Any ideas?

Ryan

Ram@S4-MTM

Get a second opinion on that alternator....

System_S4k

Changing an alternator on the S4 is the suck.

inliner311

i had the same problem on my lexus, the alternator wasnt pushing out enough volts so it drain the battery. It took 250 miles to drain it completely but then the car would die. Went into a gas station garage and asked them to test it, the guy brought out a small volt meter and said it was the battery so I bought a new battery. 250 miles later it died again, the guy didnt check it right. I was on a road trip from san diego to cleveland, i got stuck in the western part of colorado till I got a new alternator and had to change it out myself because I was in a small town that no mechanic wanted to work on my car.

bingS4

I just had a similar problem. I wore down the alternator driving too much with a bad battery - lesson learned. I replaced the battery but the volts were hanging just barely above 12, with the battery light flickering on occasionally. I picked up a remanufactured Bosch alternator for about $225 + $85 core from the local parts store and replaced it last weekend. It was my first alternator swap and wasn't too bad of a job, though I did have to stop by a shop and have them swap the pulley since I didn't have the special tool. Also, one of the little stones they use for polishing the rebuilt alternator fell out of it, luckily before I finished installing it. If you get one, give it a good shake before putting it in.

rbr

Is this a DIY job or am I better going to a shop to get this done? Also, how long does this normally take to do? Any how-to guides on this?

S4_Cinci (I S'edTFA)

battery terminals? When engine is running, the dash shows alternator output (essentially). Classic bad battery: voltmeter reads OK but car cranks slowly after sitting overnight. Clasic bad alt/voltage regulator: voltage drops while driving, esp if A/C and radio are on, you get significant swings in voltage based on engine rpm.

Bad battery can kill your alternator/regulator if left in car too long. Likewise, bad alt/regulator can dramatically shorten the life of a battery by not charging it fully.

S4_Cinci (I S'edTFA)

BTW - If you only get 11V out of the alternator, it's cooked. Should be putting out 13V+

rbr

https://pantherfile.uwm.edu/xythoswfs/webui/_xy-5066665_1

How hard do you think it is to do this? How long do you think it takes? Any words of wisdom on this?<ul><li><a href="https://pantherfile.uwm.edu/xythoswfs/webui/_xy-5066665_1">https://pantherfile.uwm.edu/xythoswfs/webui/_xy-5066665_1</a</li></ul>

HIS4

I would look at the alternator again. Don't wait too long because the bad alternator will eventually kill your battery and you'll need to replace both.