hi. i have a 1987 honda accord lx-i that i baught yesterday. when i took it home and started working on it i realized that my brake lights wont come on. i have replaced the bulbs and fuses and they a still wont come on. my turn signals, headlights, and tail lights work but my brake lights dont. what could be the problem? and if u know then how much would it cost to get whatever replaced?

 

Go for a dash dive and check out the brake switch above the pedal.
The plunger of the switch is supposed to make contact with a plastic plug in the pedal arm, those plastic plugs come out after a decade of use.
That would be the first thing I'd check, or the brake switch itself

 

yo Dude my man a little correction........

if the rubber plug is broken ( came off ) from the pedal that would make the switch stick out as if the brake pedal has been depressed thus it would make the brake lite stay on all the time ...

does the horn work?? if it does fuse is ok ,, if it does not chk under hood fuse # 4 20 amps........if fuse is ok,, at brake switch,, disconnect the plug and jump the 2 wires together white/yellow and green/white ,, if brake lite come on you got a bad switch...
if they still do not come on chk to see if you get power at white/yellow ,,,
if you do, and brake lite still not on when you jumped the 2 wires together could be bad wiring from brake switch to brake lites..

if no power at white /yellow and fuse is ok,, you got bad wiring from fuse box to brake switch

 

i have power at the yellow/white wire other four no power to them (not sure if that is an issue) so from your response i have to start my seeing if i have power at the yellow & white wire in the trunk to the two rear break lights, but spoiler brake light works??? trunk is completly ripped apart down to bare wires, what is the small black box under left rear brake light labeled pp-t20 and could this be causing the problem? and if spoiler brake light is working i am assuming that yellow/white wire works to that point? any advice would be great, thanks.

 

There are three items required for a bulb to light up. Power, ground, and a bulb that is not burned out.

Power and ground are easy to test if you have a volt meter. Unplug bulb and have someone press on the brake. See if you have voltage between the non-black wire on the bulb socket and a good ground (use a bare metal bolt).

For ground, see if you have ~0 resistance between the black wire and the ground you used before. You can also use the open/closed functionality if you have that on your volt meter.

 

rear brake light sensor (little black box under drivers side brake light) is bad, jumped white/black to black (i think) and they are working now, can i leave this jumper in place? what does a new sensor cost and what does it do, thanks.

 

It is a sensor to detect a brake bulb failure. It turns on the brake lamp warning light in the cluster when a bulb is burned out.

Is your car an 86-89? LX, DX, etc...? You should put that information in your signature.

You may be able to figure out what is wrong with the circuit. You can get an 86-89 shop manual from the hondatech link in the Online Manuals thread in the DIY section. Just make sure the display options are set to show all threads at the bottom of the page.

A new part is ~$30 from the dealership depending if there are 5 or 6 pins on the electrical connector. I would troubleshoot first before replacing. Go to a site like hondapartsnow.com and look up the part for your specific vehicle. Its under electrical/exhaust/heater/fuel, then taillight. The retail price is what most dealerships charge.

 

If it is a 3rd gen (86-89), IIRC the difference in the number of pins has to do with 2dr vs 4 dr. Not sure where you are located but I think I've got a rear tail light assy in the garage (4dr). You can call around local yards to see if they have any in that gen. Just know the 2dr and 4 dr are different, physically. Also there are "slight" differences in the lens between the years. If will fit (again 2dr to 2dr or 4dr to 4dr) just the "lines" in the lens are different...have to get real close to notice.

 

It's a 99 accord lx v6