Testing Alternator

[AspDotNetGuy]

95 Grand Am SE 3.1 liter....

Voltage light came on a few days a go. Car finally wouldn't start today. Assuming an alternator is needed.

Is there a way to test the alternator myself or do I need to take it in?

Are they hard to change? Any special tools needed?

Thanks,

AspDotNetGuy

[GTP Dad]

Take it to autozone or advance they can test if for you. If the light came on it probably went out and will need replaced. No special tools are required just make sure you disconnect the battery before you start the replacement. If you accidentally cause a short you may damage the new alternator. Make sure to get the connections tight. You also need to recharge your battery.

[AspDotNetGuy]

I tested it using an voltage meter. Looks like it is bad... the battery was holding 11.3v and it was about 10.5-11 with the car running.

I read in the manual that I have to remove the drive belt which involves removing motor mounts... is this true?

its a 1995 3.1 Litre

Originally Posted by GTP Dad

Take it to autozone or advance they can test if for you. If the light came on it probably went out and will need replaced. No special tools are required just make sure you disconnect the battery before you start the replacement. If you accidentally cause a short you may damage the new alternator. Make sure to get the connections tight. You also need to recharge your battery.

[catback23]

Originally Posted by AspDotNetGuy

I tested it using an voltage meter. Looks like it is bad... the battery was holding 11.3v and it was about 10.5-11 with the car running.

I read in the manual that I have to remove the drive belt which involves removing motor mounts... is this true?

its a 1995 3.1 Litre

You don't have to remove the belt from the vehicle just have to get it off the alternator pulley

[AspDotNetGuy]

So are you saying i Just pull the told alternator off, and put a new one on?

I will still need to get the belt on and off the alternator and its going to tight? How do I get it off?

[GTP Dad]

To remove the belt from the alternator simply loosen the tensioner located on the front of the engine and when the belt is loose pull it off the pulley on the alternator. Leave the belt in place and once the alternator is on simply loosen the tensioner and pull the belt over the pulley. Simple as that.

[xeroinfinity]

Heres a pic of what tensioner looks like and location.
Thiers a square hole, a 3/8s ratchet will fit, so you can loosen the belt tension.

[AspDotNetGuy]

OMG, thanks for the picture... I think I am going to try and do this myself. It makes me feel good when I am successful, and I save money.

I just loosed that bolt and belt will come loose? Than I tighten when I want to put it back on?

[AspDotNetGuy]

I should say than i take hte alternator off, put the new one on, slide the belt over it, and tightning the tensioner bolt will automatically tighten the belt?

[AspDotNetGuy]

I see its on springs so I have to insert a socket into the squar hole to release the pressure.

A socket wont fit, not enough room so I have to go buy a breaker bar

[xeroinfinity]

NO! They sell/rent a belt tensioner tool at the Zone for like 25$, Long handle with a very thin handle, with a ratchet 3/8s head at the end. It is tightm but a thin ratchet will get it loose.

You just insert the 3/8s head into the hole and pull the tensioner over, while holding the tensoin, slide off the belt.
Easy as cake
Then loosen the bolts holding the Alternator, and it should pull out off teh bracket.
Their is a red power wire on the back of the altnr, dont forget to disconnect the neg on the battery Before you do this.

And youre welcome!

[JMeek]

You can also pull the tensioner back with a pry bar. It's a little tricky, but I've done it that way a couple of times.

Another note: Be sure your battery is fully charged (or at least near fully) when you put your new alternator on. A completely dead battery can destroy a new alternator.