alts....

[Byrd14]

does the 3.4's alternator the same with the 3.8's?

I've been having a problem with battery stuff lately... couple days ago it went -32*c with -49*c Windchill.... so plugged the car... next morning... wont start... checked the battery... the fluid in it is frozen... so the battery must go... bought a new high cold crank battery.. started... checked the battery gauge.. it was like almost at the red(highest) area... so i drove it around couple times... then when i looked at my battery gauge it was almost at the middle... now im cluless... could it be a fried alternator?

[Mr. Logger]

Re: alts....

They are two different alternators.

[jnxV6]

Re: alts....

It could be, if your alternator is fried and you drive around it will drain the battery. It also could be your car doesn't like it when it is that cold. :rolleyes:

[00 Silver 6]

Re: alts....

mine fluctuates like that as well, i have a brand new alternator with a brand new battery... im also driving in -5 degree weather

[kristen]

Re: alts....

your batt. gauge should sit right above the mid way point. when your car is running, it's not running off the battery. so if your gauge is going below the half way point then your alt is dead and your running off the battery. the batte. won't stay charged since alt isn't recharing it.

[Byrd14]

Re: alts....

your batt. gauge should sit right above the mid way point. when your car is running, it's not running off the battery. so if your gauge is going below the half way point then your alt is dead and your running off the battery. the batte. won't stay charged since alt isn't recharing it.

so basically if it stays above the middle line ill be just fine?

[kristen]

Re: alts....

just above that line. you don't want it any higher than that

[Byrd14]

Re: alts....

well i noticed that when i start the car its almost at high... but after 10 mins of warming the car up it stays like a little above the middle line... so thats good then...

[00 Silver 6]

Re: alts....

just above that line. you don't want it any higher than that

well im screwed then

[kristen]

Re: alts....

well im screwed then

what is yours doing

[00 Silver 6]

Re: alts....

its at that 2nd line, stays there most of the time... if im idling in traffic it drops down to like a little more than 13 volts

[kristen]

Re: alts....

does it drop and then come back to midway? what else is hooked up to your battery?

[00 Silver 6]

Re: alts....

2 audio amps are hooked up to the battery as well, itll sit at the line before the line for 18, then occasionally drop down to about 13 while im not on the gas

[oliver99]

Re: alts....

Hi,

well if you want a really accurate reading, don't trust the gauges in your dash, use a (digital) voltmeter to be sure. I've once spent quite some time looking for a problem only to find the gauge was totally off.

Another thing, even if the gauge is not off, the gauge is measuring the voltage at the dash connector, not the battery or in other parts of your electrical system. If a component draws, say 2 Amps (not uncommon in a car), and some wiring with a fuse in line has a resistance of 1 Ohm (not uncommon either), you will have a voltage drop of 2 Volts along that line. What I'm saying is: if you want to seriously diagnose the problem, use a voltmeter and probe around the engine bay.

Check the voltage at the battery, not at some ground, but across the battery terminals, and compare it to the reading at the alternator (this time across the alternator). They should be about the same. The idle voltage should be 13-14 Volts. If the engine is not at idle, the voltage should never exceed 15 Volts, the PCM sets an error code if the voltage is higher than that. Turn on all the loads you have (lights, fan, A/C, etc). The voltage should not drop below 12V. If it does, the alternator is not regulating anymore.

Don't attempt to disconnect any connector on the alternator, let alone the big power wire with the engine running and/or the battery connected! This can kill your alternator or disable the regulator, causing the voltage to fluctuate uncontrolled. You can read all voltages without disconnecting anything.

If you're measuring with the digital voltmeter, also set it to an AC range and measure voltage at the alt. It should be zero. If it's not, one of the rectifier diodes is shot and you have (unregulated) AC on the power line, which is also
something that can damage battery or other components.

Best regards.


Oliver