With the red battery light on the dash, I'm assuming the alternator has gone bad. I checked the voltage on the battery and it was 12.2 VDC with the engine off. Started the engine and the voltage dropped to 11.8 VDC. Drive belt is fine. So is there anything else to do other than replace the alternator? Could it be a less expensive part such as a voltage regulator? What would you do next?

 

1. Car was fine and you just saw the battery red sign?

2. Is the car turning fine?

3. You measured the battery voltage was the engine off?

4. Have you measured the voltage across while the car is running?

 

Voltage regulator is built into the alternator. Since you already checked voltage both running and not running. The only other check before replacing the alternator, would be wiring. Che the wiring at the alternator, and the battery cables.

 

1. Car was fine and you just saw the battery red sign? Yes, started in the garage after sitting overnight and the light didn't go off. Has never come on before.

2. Is the car turning fine? Yes, runs fine, but there does appear to be a whining sound that wasn't there before. Could be alternator bearing noise.

3. You measured the battery voltage was the engine off? 12.2V

4. Have you measured the voltage across while the car is running? 11.8V

 

Looks like I have a Saturday morning project to remove the alternator. Battery cables are clean and tight. I'll check the alternator wires from under the car after I get the engine shield off.

 

Just for reassurance, you may want to go to your local Oreilley's. Their FREE test diagnoses lots of different parts of your electrical system.

 

Simple test at Auto Zone will tell you if your alternator is bad.

 

With the engine running just put your positive lead to the battery terminal on the alternator. Then put the negative lead to a chassis ground. Read the voltage. That's the same thing as if you take it off and take it in to be tested. If it's on the car, they are going to test it just the same as he already did. By putting the leads on the battery terminals, and reading the voltage. The fact the voltage is lower with the car running says it is just running on the battery. It's a simple system, all that is left is a wire issue, or the alternator. With the whining, it's pretty obvious the alternator is in need of replacing.

 

Thanks guys for the comments. I replaced the alternator and it fixed the charging issue. Unfortunately, the plastic lock tab on the 3 wire plug-in connector on the back of the alternator broke. It's a squeeze tab to release the connector. I couldn't find a new connector, so I plugged it in and it seemed pretty tight. I guess time will tell if this connector will vibrate loose.

 

do you happen to have a child who plays a woodwind instrument? You can trim an old reed, and use it as a wedge to hold it in place.

 

Oh well, at least you'll know what to look for. I'm glad that you got it repaired and are back up and running again.

 

i have the same issue - charging light is on and there is a distinct whine from the side where the alternator sits. Voltage is similar to yours, running and not. How Is the alternator replacement process? Do you have a DIY? Thank you.

 

No DIY, but here's what I remember and a few photos:
1)....disconnect battery
2)....remove drive belt by taking pressure off tensioner
3)....remove pulley from power steering vane pump
.....all other steps will be performed from under vehicle. Tough doing if you don't have a lift.
4)....remove undercover from vehicle (lots of 10mm bolts)
5)...loosen 3 bolts from front of alternator...(1 on bottom, 1 on side, 1 on top) (see photo)
6)... remove the bolts that hold the transmission cooling lines so they can be flexed down for removing alternator (see photo)
7)....remove bolts & support alternator with hand or front sway bar
8)...unplug harness....be very careful, it has a push in lock tab,may be hard to get loose. My locking tab broke when I compressed it.
9)...disconnect battery connection from alternator....(1 nut ) (see photo)
10)...I was able to wiggle it out over the sway bar & in front of radiator, but it is tight
11)....reverse the steps to install....I did test everything,before bolting the undercover back in place

 

....this happened to me awhile back when I replaced my alternator. I used a portion of a popsicle stick & wedged it in, so far no issues

 

thanks for all the info really helps getting ready to do this