Hi, I have a 2007 Chevy suburban that is extracting voltage while it sits causing our vehicle not to start and buying new batteries every 1.5 years. what could be causing the battery to extract voltage while sitting?

I haven't heard about problems like that other than in a flood damaged vehicle.Did you buy it new?
To check for a battery drain yourself,disconnect the battery large cable and place a 12 volt test light between the cable and the battery positive.If you see a bright light on the test light you do have a vehicle drain,if it's dim don't worry about it.Now,if the light is bright pull one fuse at a time until the light goes dim,this will be the circuit draining and you can now trouble shoot that circuit.Don't cause a bright light by opening a door or turning on the key.DO NOT TRY AND START THE VEHICLE while the test light is hooked up.

Check all fuses under the hood. Test the coil with an ohmmeter. Check for battery voltage on the coil primary with key on.
If all good, suspect the crank position sensor. A bad sensor will cause no spark.

Is this a 1500 Silverado? I looked at my database, didn't see pcmb fuse? These databases are not always correct. On some gm makes and models, the pcmb fuse supplies voltage to both the pcm and fuel pump. Unplug the fuel pump, see if fuse still blows? If it does, it's not the fuel pump. Can't rule out wiring circuits? Has this vehicle sat for a long time?

This is a random misfire of all the engine cylinders, the causes are many and each must be diagnosed to fix the problem. If you click this LINK you will go to the best info I know of for diagnosing the problem.

Not sure what problem you have with the battery. Your vehicle is 4 years old and could have a bad cell. This would cause intermittent problems. Buy a new battery.

HI,When electrical components such as a stater motor get hot they draw more amperage thus making it harder to turn over the motor. There are 3 possible things going bad (1) Battery (2) Battery Cables (corrosion) (3) Starter. I hope this helps lead you to the proper diagnoses.

you have a bare wire leading form the alt too the field prob right at the intake manifold!!

GM has had a issue with the clusters in the 2003-2005 trucks. The cluster will be replaced for free for your truck if it has less then 70k miles. I would take it to your local dealer and tell them that the voltage gauge sticks at times. They should order one for you, takes 1-2 days and replace it for you at no charge. If this does not fix the problem, you will have a new cluster at no charge.Unless the battery light comes on, the alternator should be good. This is a copy of the GM bulletin.

#07187C: Special Coverage Adjustment - Instrument Panel Cluster Gauge Needle Function - (Mar 20, 2009)

This special coverage covers the condition described above for a period of 7 years or 70,000 miles (110,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.

Dealers are to replace the instrument panel cluster after the condition has been verified. The repairs will be made at no charge to the customer.

For verified failures between 70,001 miles (110,001 km) and 80,000 miles (130,000 km) on U.S. vehicles, dealers are to provide the customer with an instrument panel cluster (IPC) only. Any additional costs, including labor to replace the instrument panel cluster, will be the responsibility of the customer. Dealers are responsible for the return of the customer's IPC back to the Electronic Service Center.

For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after September 28, 2007 for 2003-2004 model year vehicles, and March 23, 2009 for 2005 model year vehicles, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to September 28, 2007 for 2003-2004 model year vehicles, or March 23, 2009 for 2005 model year vehicles, must be submitted to the Service Contract provider.

Involved are all 2003 and 2004 model year and certain U.S. 2005 Cadillac Escalade, Escalade ESV, and Escalade EXT; Chevrolet Avalanche, Silverado, Suburban, and Tahoe; and GMC Sierra, Yukon, and Yukon XL vehicles built within the following VIN breakpoints: 51100014-51247028 / 5E100002-5E223209 / 5F800001-5F882297 / 5Z100003-5Z224691

Good luck friend.

test the battery make sure its good, also when it wont start does the engine spinor do you get nothing ?

There is some things to check....

(1) Is your alternator charging? take your vehicle to Advanced Autos, Napa or someone like that and have them test your alternator.
(2) Is there something in the vehicle causing excessive drain on the battery when the motor is not running... like is the interior light may be on or something to that affect.
(3) Are you doing enough driving to recharge your battery? short stops and starts is not good for a battery as you may rob more energy from the battery then you are putting back in.
Sounds like something is draining your battery, something must be left on in the vehicle, Advanced Autos or Napa should be able to tell if something is draining your battery when the vehicle is off.