[Projectj128]

OK maybe not so odd.

The other day while driving around 55mph my rpm suddenly dropped by 300rpm or so, I noticed that my voltage dropped as well, not sure to how many volts but it was significant, then last night I was driving home and my car died on me, suddenly, no warning whatsoever, I checked the Voltage at the battery and its reading around 12 volts (engine off) and when the engine is running it showing around 14+ volts. Is there a way I can check the alternator with it still in the car?

 

[Poncherello]

Is there a way I can check the alternator with it still in the car?

Yes, start the car and then disconnect the battery. If the car continues to run the alternator is doing its job, if the car dies then the alternator is not working properly. The battery is only used to start the car, the alternator provides electrical power to the electrical system after the car is running and also charges the battery.

 

[Projectj128]

I seriously can't believe I didn't even think of that It's been a long week Thank you

 

[mr turbovett]

Yes, start the car and then disconnect the battery. If the car continues to run the alternator is doing its job, if the car dies then the alternator is not working properly. The battery is only used to start the car, the alternator provides electrical power to the electrical system after the car is running and also charges the battery.

disconnecting the battery when engine is running is a sure way to fry the alternator. the alt is going to see a totally empty battery nand crank up the juice to much:crazy:.

 

[Poncherello]

disconnecting the battery when engine is running is a sure way to fry the alternator. the alt is going to see a totally empty battery nand crank up the juice to much:crazy:.

I wasn't aware of that.......I must be lucky because in the several times I have done it that way I have not had any problems. :huh:

Based on the info turbo provided, I wouldn't recommend doing it my way. :thumbsup:

 

[The Bad]

Any major parts store could / would load test it.

 

[ND4g]

disconnecting the battery when engine is running is a sure way to fry the alternator. the alt is going to see a totally empty battery nand crank up the juice to much:crazy:.

Excuse me. :lookinup: If the battery is disconnected the alternator does not see it as "empty" nor can it "crank up the juice".
A missing battery equates to nothing more than an open switch. On the other hand, there are a few other issues one should consider when disconnecting anything under the hood with a running engine. Watching out for moving parts, not getting burned on hot parts, where to secure live wires when disconnected, etc.

Like The Bad said; take your car to a major auto parts store, such as Discount Auto, Advance Auto, or Pep Boys. They all have free diagnostics and they can load test with a simple hook-up right in the parking lot.
There are also some decent battery chargers that are sold in Walmart for about $50, and they feature alternator/load testing as one of its capabilities.

 

[crowvet]

OK maybe not so odd.

The other day while driving around 55mph my rpm suddenly dropped by 300rpm or so, I noticed that my voltage dropped as well, not sure to how many volts but it was significant, then last night I was driving home and my car died on me, suddenly, no warning whatsoever, I checked the Voltage at the battery and its reading around 12 volts (engine off) and when the engine is running it showing around 14+ volts. Is there a way I can check the alternator with it still in the car?

You just did check it in the car.... 14 volts is perfect. you have a intermittent issue with either the voltage regulator (inside the alternator) or a bad battery connection. Unfortunately all the testing in the world will not isolate the problem if it is working. #1 check your belt for slippage. #2 check your battery connections positive and negative, be especially critical of side post connections.If these things check out, replace the Alternator and be done with it. There is a slight possibility that your ECM or wiring could be causing a intermittent issue. But honestly you could not trace all those possibility s out for the price off a Alternator.

 

[Projectj128]

Thanks for the info guys, I checked the battery cables, they both looked great, practically brand new. the belt doesn't seem to be slipping, but hell if I have to change the Alt I might as well change the belt as well. I will keep ya'll posted as to what the problem is, if/when I find it