3rd Brake Light - - Toyota Nation Forum : Toyota Car and Truck Forums

REAPER STRAIN · 09-19-2005, 02:08 PM

I am looking for the proper resistor for the 3rd brake light. I took this light out from the back window. The warning light on the dash comes on when I mash on the brakes. I read that all I need is a resistor to but in its place. I was at radioshack trying to find the right one and I got lost in the variety. I know that the light bulb is rated 12V, and 18 Watts. Using the Ohm's equation I got a rating of 8 ohms. Is that right? Can I use a 10 ohm/ 0.25Watt resitor? If not what can I use?

SnakeyeS · 09-19-2005, 04:56 PM

You cannot use those dinky 1/4W resistors.

Think about it. You want to mimic the bulb still being there. So if the bulb was pulling 18W, you want your resistor to pull around 18W as well(its probably ok to use as low as 12W if you can't find 18W). The resistor you're looking for will look more like this:

REAPER STRAIN · 09-19-2005, 05:46 PM

That thing is pretty big. So, long story short, I need resistor that is at least 12v and any ohm rating over 8 right? Anything else?

***zoni*** · 09-19-2005, 05:50 PM

just watch the heat output very closely...

what you can do to get around this is connect the positive and negative from that 3rd brakelight to the positive and negative from one of the rear taillights. that solves the heat issue, and you dont have to buy anything, besides wire.

SnakeyeS · 09-19-2005, 05:57 PM

^ that should work as well

REAPER STRAIN · 09-20-2005, 02:14 AM

in terms of hear outputs what would you suggest? Im really leaning towards installing the resistor instead running wires to the brake lights because I maybe getting a rear spoiler soon with a built in light. So inserting a resistor would be ideal.

So, from what all are saying is I need a resistor with a low heat output, more than 12v and 8 ohms rating and I should be set right?

Im looking at radioshack.com and all I see are these lego size resistors. That cant be right can it? They look like the metal one in the picture above.

http://www.radioshack.com/category.a...4%5F004&Page=1

88 LE · 09-20-2005, 03:49 AM

Quote:

Originally Posted by REAPER STRAIN

So, from what all are saying is I need a resistor with a low heat output, more than 12v and 8 ohms rating and I should be set right?

I would use atleast a 20W or 25W resistor.

8 ohms should work.

Quote:

Im looking at radioshack.com and all I see are these lego size resistors. That cant be right can it? They look like the metal one in the picture above.

http://www.radioshack.com/category.a...4%5F004&Page=1

Those are ceramic wirewound resistors.

The one that snakeyes posted has a integrated heatsink.

Try a electronics supply shop. Radio Shack lacks on electronic components.