tail lights help asap

New bulb cost a couple bucks. Buy one, replace the bulb, then if it still does not work, return for ideas. Don't make a bad bulb more work than it is. If the one bulb in the light assembly is flashing and one is not. It is 99% a bulb problem.
 
New bulb cost a couple bucks. Buy one, replace the bulb, then if it still does not work, return for ideas. Don't make a bad bulb more work than it is. If the one bulb in the light assembly is flashing and one is not. It is 99% a bulb problem.

^^

way to fix a bulb that doesn't blink? Replace it. Doesn't matter if you've looked at it and it looks fine. It's evidently not.
 
Do you have a digital volt meter?? Time to start testing to see if you are getting power to the socket

Ditto

If it is the wiring at the socket, then your ground is good and the power lead to the low filiment is good (because you said the bulb lights up when the headlights are turned on). It is possible that the power lead to the high filiment is loose or not getting power (which is why the bulb does not light for turnsignals or hazards)

time to break out the volt meter
 
Could also be a problem with the actual contact in the bottom of the socket. Sometimes, the contact will wear to a hollow shape and even a new bulb will not make proper contact. As mentioned, get out the meter and check for voltage.