Automotive Question - Tail lights

[iftheresaway]

The other day, my husband was following me home and noticed that my tail lights were out on both sides, so no one could tell if I was stopping or turning. I quickly bought new bulbs and replaced them, but when I did so, I noticed what I assume must have been corrosion -- a thick, almost chocolatey-looking substance coating the base of the old bulb and the socket that it was plugged into. I changed out the bulbs, and now the new ones still don't work. Is this something I can fix myself? Is it something I can ask them to fix when I get my oil changed at Meineke or Valvoline or whatever? Any advice would be great -- I'd like to get this fixed on my lunch break, if I can -- I'd really rather not drive around with no tail lights!

Thanks in advance for any advice.

[GaryM]

That coating may have been a protective grease applied to prevent corrosion rather than a product of corrosion.

You say the tail lights were out on both sides. But depending on the model of car there are either one bulb on each side with two filaments, or two bulbs, each with one filament. Don't know which you have, but it would be unusual for the Stop/Tail light bulbs on both sides to fail at once. That would be four filaments to fail. You may have a wiring or fuse issue instead. If you don't have yellow turn signals on the back, it's common to use one bulb for both stop and tail lights. None of these were working?

[Gary T]

Let's start with correct terms. Taillights are red, somewhat dim, and come on when the headlight switch is turned on (to either the parking + taillight position or to the headlight position). Brake lights are red, bright, and come on when the brake pedal is pressed. Sometimes they use the same bulbs as some or all of the taillights (dual filament bulbs, one being dim and one being bright), sometimes they are separate. There also is probably a high center brake light. Turn signals on some cars are red, using some or all of the brake lights, and on other cars are orange/yellow using separate bulbs.

To help you efficiently, we need to know the following:

Year, make, and model of car (knowing the engine size could help me find relevant info more quickly).

Do any of the taillights come on when the headlight switch is turned on?

Do any of the brake lights come on when the brake pedal is pressed (might need ignition switch in the "on" position - not the engine running, just the ignition turned on)?

Do any turn signals, front or rear, and/or the turn signal indicator come on with the turn signal switch turned on (ignition switch will need to be on)? Do any of these lights flash? (Check both sides, of course.)

Do any lights come on with the hazard light switch turned on (check front and rear)? Do they flash?

[iftheresaway]

Thank you for getting me straight on the terms - I know that there were lots of things going on back there, but I wasn't sure what.

I have a 2002 Chevy Cavalier. When I turn on the headlights or step on the brakes, the tailights & brake lights come on (as far as my husband could tell in the bright sunlight).
My front turn signals come on when I hit the turn signal stick, but they flash rapidly. My rear turn signals do not come on.

Again, I appreciate anyone taking the time to help me out.

[Joey P]

Originally Posted by iftheresaway

When I turn on the headlights or step on the brakes, the tailights & brake lights come on (as far as my husband could tell in the bright sunlight).

Originally Posted by iftheresaway

my husband was following me home and noticed that my tail lights were out on both sides, so no one could tell if I was stopping or turning

These two statements contradict each other.

[Gary T]

Your car uses the same bulbs (dual filament) for all three functions. The taillights use the dim filament, the brake lights and turn signals use the bright filament. To allow the brake lights and turn signals to work at the same time, the brake light wiring is routed through the turn signal switch. When you select, say, a left turn, the left brake light is disconnected and that bulb's bright filament is connected to the turn signal flasher. So, if the brake lights all come on, that tells us that the bulbs and the wiring to them are good.

Turn signal flashers are calibrated to the number of bulbs they have to light up. When a bulb in the circuit isn't working, the flasher still provides power to the other bulbs, but blinks at a faster rate. It's handy to know this as it lets the driver know when a bulb has burnt out (or, in this case, isn't working for some other reason).

Brake lights work, front turn signals work, rear turn signals don't = faulty turn signal switch. I doubt that an oil change place is prepared to do this repair. I'd suggest taking it to a good independent shop or dealership. You'll likely have to arrange to leave it for a day.

[Nuke]

First check your fuses for the brake lights. If they're OK, then check the brake light switch that will be attached somewhere on or close to the brake pedal. The black substance is called dielectric grease and it protects the ends of the bulb and its connector from moisture and is normal.

[Gary T]

If the high center brake light works, then the brake light fuse and switch are okay. If it doesn't work, first check/replace its bulb, and if it still doesn't work, then test the fuse and switch.

If the regular (left and right) brake lights work, and the front turn signals work, a faulty turn signal switch is the only thing that would prevent the rear turn signals from coming on.

If there's still some question about what lights are actually working, have the observer put his eyeball right next to the lens, shading out the sun with his hand. It should be clear beyond any doubt which lights are coming on and which aren't.