Third Brake Light

[Geoff Peace]

I have a 2005 1 litre Yaris, [old style model] The brake light bulb in the tailgate lasts about 3-4 months by which time the glass is black, which obviously diminishes the light intensity. This has happened many times. I know what is happening, the tungsten filament is vaporising and depositing on the inside of the glass, but how to prevent it? I have checked the wiring for poor contacts including the earth, the bulb holder has been cleaned, I have tried bulbs from different manufacturers, No difference. I do not keep the brake light on when stationary, at traffic lights for instance. I have thought about an LED bulb but they are too bulky for the enclosure. Has anyone else had this problem? All suggestions welcome.

Regards Geoff Peace.

[Geoff Peace]

I have a 2005 1 litre Yaris, [old style model] The brake light bulb in the tailgate lasts about 3-4 months by which time the glass is black, which obviously diminishes the light intensity. This has happened many times. I know what is happening, the tungsten filament is vaporising and depositing on the inside of the glass, but how to prevent it? I have checked the wiring for poor contacts including the earth, the bulb holder has been cleaned, I have tried bulbs from different manufacturers, No difference. I do not keep the brake light on when stationary, at traffic lights for instance. I have thought about an LED bulb but they are too bulky for the enclosure. Has anyone else had this problem? All suggestions welcome.

Regards Geoff Peace.

No thoughts from anyone! I must have the only Yaris in the land with this problem!!

[junebug1701]

Are you sure all the available LED bulbs are too bulky? There are so many different sizes now. Look on eBay and on sites like this:

V-LEDS

Oznium

[minidoughty]

Toyota do a led one in Japan for the vitz, just need the part no. to order it from your dealer.

[Geoff Peace]

Are you sure all the available LED bulbs are too bulky? There are so many different sizes now. Look on Ebay and on sites like this:

V-LEDS

Oznium

yes they are much too large, the bulb and holder are only 15mm. wide and the whole thing has to be inserted into the lamp enclosure of the3 same diameter. I have encountered bulbs going black before but not with the monotonous regularity of these wretched things! Thankyou for your reply.

Regards Geoff Peace.

[Cyker]

Some sort of moisture seeping in maybe? Or voltage level problems? For sure this is not normal behaviour!

[Madasafish]

I suspect a corroded connection - check them all including earth leads and clean with fine emery cloth or sandpaper.

Do you slam the boot? That will not help.

[Geoff Peace]

I suspect a corroded connection - check them all including earth leads and clean with fine emery cloth or sandpaper.

Do you slam the boot? That will not help.

Thankyou for the suggestions, There is no corrosion on any of the terminals, the supply voltage is fine and the earth return has no resistance. All terminals are bright and clean and smeared with silicone grease. However slaming the boot lid is a most interesting point, it could well cause the lamp filament to vibrate and cause the probem. My wife drives the car mostly and has had several hatchback cars over the years without any problem regarding the brakelight. Also she does not keep her foot on the brake at traffic lights etc. I have now given her a feather duster with which to close the boot so we shall see. I will get to the bottom of this problem somehow. Once again thankyou for your interest.

Regards Geoff Peace.

[t-spiritpete]

I suspect a corroded connection - check them all including earth leads and clean with fine emery cloth or sandpaper.

Do you slam the boot? That will not help.

Thankyou for the suggestions, There is no corrosion on any of the terminals, the supply voltage is fine and the earth return has no resistance. All terminals are bright and clean and smeared with silicone grease. However slaming the boot lid is a most interesting point, it could well cause the lamp filament to vibrate and cause the probem. My wife drives the car mostly and has had several hatchback cars over the years without any problem regarding the brakelight. Also she does not keep her foot on the brake at traffic lights etc. I have now given her a feather duster with which to close the boot so we shall see. I will get to the bottom of this problem somehow. Once again thankyou for your interest.

Regards Geoff Peace.

Hi Geoff,

Quote:- "All terminals are bright and clean and smeared with silicone grease" I take it you mean on the outside of the contacts not on the contacts as silicone grease does not conduct electricity.

Regards Pete.

[Geoff Peace]

I suspect a corroded connection - check them all including earth leads and clean with fine emery cloth or sandpaper.

Do you slam the boot? That will not help.

Thankyou for the suggestions, There is no corrosion on any of the terminals, the supply voltage is fine and the earth return has no resistance. All terminals are bright and clean and smeared with silicone grease. However slaming the boot lid is a most interesting point, it could well cause the lamp filament to vibrate and cause the probem. My wife drives the car mostly and has had several hatchback cars over the years without any problem regarding the brakelight. Also she does not keep her foot on the brake at traffic lights etc. I have now given her a feather duster with which to close the boot so we shall see. I will get to the bottom of this problem somehow. Once again thankyou for your interest.

Regards Geoff Peace.

Hi Geoff,

Quote:- "All terminals are bright and clean and smeared with silicone grease" I take it you mean on the outside of the contacts not on the contacts as silicone grease does not conduct electricity.

Regards Pete.

I take your point, the silicone grease is simply to prevent any further corrosion, not to facilitate conduction. Years ago everyone used vaseline but it can cause some plastics to go brittle over time. Thankyou for your interest.

Regards Geoff Peace.