2002 GP Battery/Charging System Light

[Reynard]

Tried to find a similar thread that already addresses my issue, but couldn't find one. If I'm reposting something that has already been hashed - sorry in advance.

So.... I have a 2002 GP GT 3.8 with 131K on it. This evening the Battery/Charging System Light illuminated while I was driving. The battery was replaced in the summer of 2008 so I am fairly certain it is not a battery issue. I am guessing that since it is original, the issue is most likely the alternator.

The lights dimmed slightly and I do not think this is a false illumination.

My questions are: 1) Is there possibly something else in the system that can create this issue?

And, rather embarrassingly: 2) How hard is it to replace the alternator for a novice such as myself? Does anyone perhaps have a guide from past experience? I found one from a Google search that details for the supercharged 3.8, but it seemed to focuses a lot on dealing with the SC pulley.

If it is not a recommended procedure for those less mechanically inclined (the biggest project I have done personally is replace the AC/Blower motor under the passenger side dash) can anyone share their thoughts on what size bill I can expect at a shop?

Everyone here as been super helpful in the past on other issues I have had so thank you in advance!


- Reynard

[gmtech1]

Sounds like a alternator issue. Check the connections at the battery for corrosion and tightness, check the connections at the alternator. If you have a meter you can check voltage at the battery with the engine running, should be around 14v. If it stay around 12v or less you probably need an alternator. Not supercharged? It's a easy job to do. Disconnect the battery first!

Depending on what the shop charges for a alternator I'd guess about 200-300.00

[Reynard]

Originally Posted by gmtech1

Sounds like a alternator issue. Check the connections at the battery for corrosion and tightness, check the connections at the alternator. If you have a meter you can check voltage at the battery with the engine running, should be around 14v. If it stay around 12v or less you probably need an alternator. Not supercharged? It's a easy job to do. Disconnect the battery first!

Depending on what the shop charges for a alternator I'd guess about 200-300.00

Thanks!

Where I'm at I don't have access to a volt meter. Does anyone know if a place like Advance Auto Parts would be able to test the voltage?

Also, I've read that removing the coolant reservoir is recommended to get the accessory belt off the tensioner. Anyone have thoughts on this?


- Reynard

[gmtech1]

I think Advanced will test your alternator if you take it to them. Check with them to be sure. Removing the resivoir does give you more room.

[Tech II]

Assuming a 3.5 year old battery can't be bad?

Just bought a backup voltmeter, on sale at Sears, for $11.....they are cheap....good to have around the house....

Like GMTech1 said, most autoparts stores will check your charging system for free, even Sears.....

But it is so easy to check yourself......first, you want to remove your battery cables......make sure key is out of the ignition, and nothing is on......remove the neg cable first, then the positive......look for corrosion on the contact points of the cables.....if present, a baking soda solution or a can of Coca Cola(this cleans cables and we drink it, ha-ha) will clean them......wipe clean, and then wire brush them.....then coat with dielectric grease.....if the 8mm bolts are corroded, they should just be replaced.....re-attach the positive cable first....then the negative....

Attach voltmeter to neg and positive cables......should read 12.6 volts.....may be a little lower due to age of battery, and if alternator has not been charging.....if the vehicle cranks ok and starts quickly, reading should be 14.0-14.5 volts(with nothing on).....now wait for car to get to normal operating temp......read voltage......because the rpms have dropped(normal), the output of the alternator will be lower, but should be around 13.0 volts......now, turn the lights on, blower on high.....voltage should drop a little.......now increase rpms to 2000......read voltage, should increase to at least 13.0 volts......if voltage is below 13.0 volts, you have an alternator problem...

[Scrapper]

sounds like alt to me have you checked ground wire to the motor on neg. side? also you might want to check ground wire to moter to firewall usually? also you say the charge lite comes on dim that again could be diodes bad in alt?

[Reynard]

Thank you all for your replies!

Actually had a new battery last summer (2010), not sure why I put 2008 (guess I should proof read).

I went to Advance Auto this morning and had the ALT volt tested and it showed it definitely needed replacing. Swapped out the old with the new ($149.00 with $12 core). Super easy job!

I initially had a problem with no power and not being able to start after finishing: checked the battery terminal several times, but guess I just didn't have a good connection (feel rather embarrassed on that one).

Once again everyone here has come through! Many props!

- Reynard