I’m new, and not a car guy. Anyways, my taillights went out, both of them, I replaced both bulbs on my 97 Honda passport, but both taillights are still out. The right break light still works, but the left (Driver) hasn’t worked for years a short. Anyways, I checked the fuses and they look like they are in tact, I was wondering what might be the cause of the taillights not working, and how to fix it.
Please note, I did have an IID installed on the car 3 weeks ago.
When you turn the headlight switch on, it energizes the coil of the tail light relay which closes the contacts in the relay, which causes the tail lights to come on.
The problem with the left brake light is due to a bad connection to that light, not a short. Otherwise a fuse would blow out and none of the brake lights would work. The problem could be due to a bad ground connection to the left light or there may be a problem with the turn signal/flasher circuit. See if the 4-way flashers work. If the light works that way then the ground to that side is okay and the trouble may be with that switch. Also check the left turn signal operation.
Can you hear the tail-light relay click when you turn the headlights on? Ask a helper to turn the switch while you listen for the “click” at the relay. Sometimes it’s easier if you use a long screwdriver as a stethoscope. If it does click, that doesn’t automatically imply the relay is working. If it clicks then you have to probe using a test light that the relay output to the tail-lights is energized. The method is, you use a volt meter or test light and just follow the tail light circuit along point to point until at some point you loose the power, then you know where the problem is, a broken wire or something. If you feel lucky you can start instead at the tail lights. If you have power to the bulb, but they aren’t lighting, either the bulb is bad or not making a good contact or the bulb socket isn’t properly grounded to the chassis. I had the latter problem one time w/my Corolla, the wire that was supposed to ground the socket to the chassis had come loose.