brake light issue

Hello - I have a 1998 Tacoma DLX. Both tail lights work (when headlights are on) but neither brake lights work, however, 3rd brake light does work. I am assuming that the brake light switch is functioning properly since the 3rd brake light works (please correct me if that is a bad assumption...also assuming there is only one brake light switch for all 3 lights). I checked the stop light fuse and it is good. The tail light bulb and the brake light bulb is the same bulb (2 filament bulb). Since the tail lights work I am assuming that there is no short (bad assumption?). Any help diagnosing the problem would be greatly appreciated.

 

Double check your bulbs at times one filament could fail.

It can`t hurt to try a new bulb before serious trouble shooting starts .

Check for voltage at the socket when the brakes are applied.

Does your truck have an evil 4 pin converter box that causes all manor of light problems always wise to check.

If you find nothing that might cause the problem look to physical damage to the light harness.

No fresh holes drilled in the cab by Chance??

Good luck!!

 

yep, replaced the bulbs. just checked the brake light switch and it is working. I also checked to ensure that there is power to the switch and there is. Now the third upper brake light is not working ugh. Going to check the voltage at the socket next as you suggested. I am also going to check that I have power going to the wiring connector to the tail light assembly. There is some corrosion and rust on the sockets. Would a ground issue at these sockets affect the third upper brake light as it is now not working either. I have looked at a wiring diagram but I must admit I am not good at reading/understanding them.

Also I am not familiar with the evil 4 pin converter box...can you enlighten me?

 

I would look at the brake light fuse it might have opened in your exploring .

It is a converter that takes the brake tail and turn signal lights and puts all of them in one bulb per side for trailer lights.

That causes so many light problems. You might not have one on your Truck.

It would be on the left side attached to the tail light harness.

 

I’m having a similar issue. Driver side brake light isn’t triggered by the brake but the bulb works and lights up when I unlock the truck. Checked the fuses, rewired the ground, checked the socket. If it’s the switch I think they would all not work. tail light works fine too.

 

Might want to double check your bulb the tail light blinks with the alarm.

The brake light has a second filament that could be broken.

 

turned out to be a broken/chewed wire under the truck.

 

Similar issue, aftermarket alarm was wired like trash.