My brake light doesn't work on passenger side and turn signal on passenger side goes real fast. I replaced complete back light and still doesn't work. Checked fuses and they are ok..

Thank you so much. I am not really sure how to do this. What kind of tester do I need to test it Thank you so much. I am not really sure how to do this. What kind of tester do I need to test it

Walmart or your local auto store should sell a cheap test light. One end of test light, you ground it to bare metal part of vehicle. The pointed end you touch to bare wire, penetrate insulation where needed. If the light comes on, you have voltage.
To check ground, one end of test light touch battery voltage, the other end touch bare ground wire, again penetrate insulation where needed. If the light comes on, the ground should be ok. Walmart or your local auto store should sell a cheap test light. One end of test light, you ground it to bare metal part of vehicle. The pointed end you touch to bare wire, penetrate insulation where needed. If the light comes on, you have voltage. To check ground, one end of test light touch battery voltage, the other end touch bare ground wire, again penetrate insulation where needed. If the light comes on, the ground should be ok.