I have a 2002 Jeep Grand Cherokee and both tailights do not work. The back turn signals do work. Is it a fuse or the bulbs? If it is a blown fuse, which fuse would I need to get to replace the blown fuse? How can I tell which fuse in the fuse panel needs replacing?

when you check fuses you must use a continuity tester or a volt meter to verify they are indeed not blown also clean the contacts in the sockets and your turn signal switch may be finished and needs replacement your vehicle is now 17-18 years old by manufacturer date sticker so things fail after almost 20 years there could also be a broken wire on that socket but verify fuses so you can eliminate that cause sometimes they look good but are blown out in the corner at the top ok

Are you using the special heavy duty bulbs required for this model.

fuses good? turn signals come on but won't blink? check blinker switch under dash at fuse panel, it will be a round push incylider next to fuse panel, with signals on put your finger on round cylinder, if you don't feel it click, it's bad.also if not that check for a blown bulb in turn signals. hope this helps!!

The brake and turning lights are on a different switch than the tail lights. Check the fuse for the brake light circuit. Check to see if your front turning lights work. My guess is they won't work either.

blown bulbs flasher bad fuse blown

If one of your bulbs has blown you will get a faster relay click when you activate the indicators. It sounds as though the relay itself could be sticking / broken.

Of course it could just be a blown fuse, I would check that first before changing relays

Checked fuse & relays box under hood, usually on drivers side fender area. Should be labeled underside of cover.

There is a seperate fuse for both the right side and left side lights. Check the 10 amp fuse under the hood.

I was once a fleet manager with many Jeep Grand Cherokees 1999-2002. We had TREMENDOUS problem with REAR tailight housings. It seem the tailight/signal/back-up light circuitry is embedded in the plasticx of the housing. NO WAY to repair. Replaced with a new one from Jeep. Problem gone. ( at least until the other side went bad ) Not a guarranty, but it's a good chance it has the same problem.

Id look at the headlight switch and do some voltage tests to see whats coming out of there. Pay close attention to any wires which look like someone was in there already.People can mess stuff up faster and better than the vehicle can by itself!