rear signal lights out, bulbs good

manlan

Both rear signal lights are out, so are brake lights. Driving lights work, so are high beam lights and all front turn signal lights. What should I check? I have done some research, but I could not locate the fuse or the relay flasher for my 2004 Malibu Maxx. Appreciate any help here.

keith

Your taillights work, if I understand your post. Turn on the head lights and have someone observe the tail lights. Step on the brakes and if the tail lights go out, then you have a broken ground wire.

Cougar

See if the emergency flashers work in the rear and if the middle brake light works ok also. The brake lights and turn signals run through the emergency flasher unit. Cycling the flashers switch a few times may help fix the trouble.

waterboy

Replace the bulbs, and go from there. Keep it simple.

manlan

How do I find and fix the broken ground wire? Neither the emergency flashers work in the rear, nor the middle brake light works, although the emergency flashers work in the front. The bulbs work in the rear when I turn on the engine and parked. However, when I drive at night, all the lights in the back is dark.
Thank you very much for all the reply.

keith

I don't understand. The lights in the rear come on when the headlight switch is off? and goes off when the headlight switch is on? The taillights work during the day but not at night?

Engine running, headlight switch off
Taillights on or off?

Engine running, headlight switch on park position
taillights on/off?

Engine running, headlight switch on headlight position, brakes off
taillights on/off?

Engine running, headlight switch on headlight position, brakes on
taillights on/off?
brake lights on/off?

BTW, the fuses and the headlight relay should be in a fuse box under the hood, usually near the battery.

manlan

My car has auto lighting. When I have engine off, but radio on, the tail lights are on. When I turn the engine on, the tail lights are still on. When I press down the brake pedal, braking lights are off. Braking lights are always off. I.e. regardless engine on/off, headlights on/off, braking lights are off. I suspect that the taillights are out when I am driving b/c people give me the high-beam signal at night lately and it is always dark behind me when there is no other cars behind me.

Thanks a million.

Triedaq

Since you say that the brake lights are out, does the cruise control work? The cruise control is deactivated when you press the brake pedal. If your cruise control isn't working, you may want to check the brake light switch.

manlan

I will try the cruise control after work. What if the cruise control is working? It has been a detective work lately on finding the cause of the darkness behind my car. Appreciated your help.

manlan

Triedaq, the cruise control isn't working. How do I check the brake light switch? Thanks.

Triedaq

I haven't dealt with a brake light switch for 50 years when I replaced the switch on my 1947 Pontiac. This switch was on the master cylinder. However, I think more modern cars the switch is under the dashboard, clips on, is activated by the brake pedal lever. I think you can unplug a connector from the switch. If this is the case, unplug the connector and using a multimeter, set it on the D.C. voltage scale. With the negative lead of the multimeter connected to a chassis ground, insert the postive lead into one of the sockets on the connector. With the ignition switch on, see if the multitester indicates a voltage. If it doesn't, put the lead into the other socket. If you are not getting voltage to the brake switch, the problem is before the switch. A fuse may be blown. If you do get voltage, set the multitester on the ohm scale. The ohm should be infinite. Press the pedal and the ohms should be zero. If this isn't the case, the brake light switch is defective.
Perhaps someone more knowledgeable than I am can advise.