2006 nissan altima battery shows 12.73 volts on the multimeter but every thing electronic in the car seems like it has a weak battery. When I turn the key to start the car I get nothing at all and the volts drop to 6.5. When i take out the ignition fuse under the hood everything in the car electronically works great but i just cant start. any ideas? Im thinking the starter is gone and its drawing to many amps and thats why it makes every thing in car goes funny.

Check the charging system you might have a bad or weak altenator you should have 14 volts of the battery with the engine running good luck anytime a battery run below 12 volts the fuel pump loses pressure causing it to stall remember you alway have to have 14 volts r the engine will stall

Do you have a multimeter? If so,

1. Put the meter on Ohms and check that the new bulb conducts. It should show a few ohms. If it shows infinity (same as the old bulb), then the new bulb is also bad.
2. Put the meter on Volts, turn on the lights, and CAREFULLY check that there is voltage at the socket.

If you don't have a multimeter, try another new bulb in case the other new one was bad.

Multimeter source:
Search results for multimeter

The cheapest ones on this page are adequate for these measurements.

Was any major work done to it recently? If not find some who has experience and ask them to take another car and use 24 volts to start it once and it may start and be fine. When I rebuild engines I have to do this sometimes. PLEASE MAKE SURE THE PERSON KNOWS EXACTLY WHAT THEY'RE DOING.

Did you change the leads?

CHECK BATTERY FIRST BEFORE STARTING VECHICLE IN MORNING.WITH CLEAN TIGHT BATTERY CABLES AND BATTERY TERMINALS OR POST CLEAN FROM CORROSSION.THE BATTERY VOLTAGE SHOULD BE 12.6 VOLTS.IF NOT BATTERY WEAK.IF BATTERY VOLTS OKAY.THE STARTER SOLENOID OR STARTER IS FAULTY TAKE TO AUTO PARTS STORE TO TEST IT.AS A REMINDER TURN OFF RADIO BEFORE DISCONNECTING NEGATIVE BATTERY CABLE TO KEEP FROM LOCKING OUT RADIO.

Misses that occur only under load are typically spark related. Engines typically need about 8000 to 12000 volts of spark energy to idle, but under load and acceleration, they can require as many as 30,000 volts. Weak coils frquently can still make 10-15000 volts, enough for light cruising and idling, but insufficient for load. Further, a defective boot or carbon tracked sprak plug may fire normally at idle and cruise, but "arc" down a black carbon track in the plug porcelin under load. You should take the car to someone who has the equipment to propely examine misfires. Or if you really feel the need to do it yourself, you could try pulling all spark plugs one at a time( assuming you dont have a scantool or trouble code data to point you to a specific cylinder) and visually inspecting them. They should ALL be clean and dry and white all around. If you see any black lines or marks in the porcelin of any spark plug, replace both that plug, and the wire or coil boot attatched to it. If you dont see any dirty or wet or oil soaked plugs, you likely have a weak coil that will require scan, scope, or load testing to isolate. Most professional shops have the equipment to do this.

Check the SPARK plug condition, and AIR gap.
Regards,DT

weak battery and check that the altanator is working

Probalibly the starter solinod.