11 volts with car running usually means alternator is bad OR fusible link in the car is blown to check this measure the voltage at the big terminal on the alternator with the car NOT running it should be the same as the battery if it is low or 0 the link is blown. Check alternator at the big terminal with the car running to see if it is working. It only takes a couple of minutes to do this.
Have you checked the cable ends on the battery? Dirty or loose connections can impede current flow, preventing the battery from being able to accept a charge. If you think the new alternator may be bad (they are usually sold as "rebuilt", and a few actually are defective), start by checking that the belt is turning it, check that the wires were connected correctly. If all OK, then use your voltmeter to check the output at the alternator itself. Sounds as though you actually have a bad alternator. If you have a small home charger, disconnect the battery from car, and charge the battery overnight at 2 amps. Should read about 12.6 next morning. If not, you likely need a new battery, and still may need an alternator. I'd take a few minutes, and check all the heavy cables -- battery to starter relay, relay to starter, and ground to battery.
Temp gauge problem is probably defective sending unit, dash light problem is probably fuse or bulb.
I dunno how you are getting the 11 volt reading...
1- check voltage before you start the car( good reading is around 12.6 V)
2-start the car, and check the voltage at the battery. it should be more than 13.6 up to 14.8 V.
Now if the there is no difference in reading it means your alternator is not functioning or it s functioning intermittently. have someone increase the rpm to about 2500 rpm and see if you notice any difference in voltage.
if the voltage of the battery increase while the car is running that means your alternator is functioning.
but before you blame the battery or alternator try to eliminate any other possibility : most common one is corrosion at the battery terminals, loose battery connection, bad ground, bad connection at the alternator, drive belt...
something to keep in mind: a bad battery will kill your alternator sooner or later , same thing about a bad alternator.
Could be a dead cell in battery. Check alternator output w/ engine running, needs to be around 14.8V, use voltmeter instead of dash gauge. If that checks out, have battery load-tested. Good luck.
I'm taking the battery and alternator in to get tested now. Any other ideas?
A good battery can get drained by a bad alternator. I know this from experience (alas...). ALSO, a good alternator can work overtime if you have a weak battery. Thankfully charging systems are usually not too-too bad to figure out... usually...
A few days ago, my battery light came on. Showed about 11 volts. I managed to drive about 15 minutes home, showed still at 11 volts. Drove back to work the next day and home, still showed about 11 volts. Last night I drove out to a friends a half hour away, got a new alternator since the old one tested bad, and slapped in the new one. The battery light was still on, still at 11 volts. I mentioned to my friend it is possible my temperature gauge hasn't been working in some time, and my dash light hasn't worked in ages (could be related?). We got back to his place, car dead. We jumped it, and still 11 volts. When we went to turn it on for me to go home later in the day, it was around 10 volts, and when I turned on my head lights the rpm gauge completely died, and headlights got super dim.
Is the new alternator I got bad? Is the battery too far gone (bought just over 14 months ago). Fuses? Anyone ever hear of anything like this before?
