Brake lights help!

[nathan_d]

so my brake lights on my 86' brat aren't working... the actual lights work when i turn on the headlights but when i hit the brakes there is no change... i have checked the fuses and all looks good, just replaced the flasher

any ideas?

[GeneralDisorder]

Have you checked the bulbs? There are two seperate elements - one for the tail lamp, and one for the "brake" lamp. When you press the pedal the extra element lights up, and often just he brake element will fail, and the bulb will still work on it's "low" beam element. The low is not as bright, so usually doesn't burn out like the brake element does.

 

GD

[TomRhere]

Check your fuses, check for battery voltage at the switch on the brake pedal. One side of that connector should be "hot" at all times, other side goes "hot" when pedal is depressed.

 

Do you get the "Stop Lamp" warning light on the dash? That should light up if you have either one of the brake lights burnt out, or a bad connection to them. Just went thru the bad connection thing on mine when I swapped out the broken DS housing.

 

Not real sure as to how it works, but there's a Stop Lamp Checker Relay in the circuit. Possibly something is amiss with that, but again, I don't know how it actually monitors the circuit. That relay is located behind the trim panel of the rear cab wall, and not real easy to get to.

[GeneralDisorder]

It's a slick little device, but it will only work if a single bulb is burnt out - if both are burnt it will not function.

 

think of it like a two way relay. It's got two electro-magnets that pull on a switch. When both bulbs are good, current energizes both magnets and their two forces exactly cancel each other. If one bulb goes, that circuit is cut, and current no longer engerizes one of the magnets. The other magnet pulls the switch closed and illuminates the dash warning.

 

GD

[TomRhere]

Thanks for the info on the Checker Relay, GD.......

 

We now return this thread to your regularly un-scheduled Subaru problem.

 

 

A couple other things I thought of today,

 

Have your parking lights "on", and have an assistant hit the brakes. Do you "lose" either or both tail lights? Ifso, points towards a bad grounding of the light assembly(s). Actually, any "that light, shouldn't/should still, be "on" right now" type thing would point to bad grounding. In other words, any wierd lighting of lights = problem.

 

Possible corrosion/bad connection in one of the connectors in the wiring heading back to the rear, and there's a few of them on a BRAT.

1. Behind the PS kick panel where the wiring leaves the dash.

2. Behind the "B" pillar trim panel on the PS.

3. Is found if you remove the PS rear lamp housing, the wire loom splits here to go to both rear lamp housings.

4. PS lamp housing.

5. DS lamp housing.

 

Both #4 & 5 would only affect that particular lamp housing, or rather should only affect that side.

 

Don't have color code for what wire is what , but I can get it. Got a spare wiring loom from an '86 out in the garage.

[nathan_d]

The fuses are good and i no that at least one of the light bulbs is good as i just replaced it the switch beneath the pedal seems to be depressing right

[heartless]

upon reading your original post, my first thought was bulbs, second thought was the switch under the pedal...just because it depresses ok does not mean that it is functioning properly.

first - look at the switch closely in relation to the pedal in its non-depressed position - how close is it to the pedal arm? it "should" be just barely making contact with the arm - no more than say a matchbook cover of space between them. as mentioned already - check for power to the switch...

i would then replace BOTH bulbs with brand new ones just to be 100% sure they are good.

if that checks ok, then would be checking the wiring/connections with the assistance of a helper in the cab pressing the pedal as needed.

and dont neglect to check the grounds - rust around ground locations can be the culprit in a lot of electrical issues...

[Gloyale]

It's been stated that there are two seperate filaments. But just to make sure have you checked that you have the correct bulbs that actually have two contacts and filaments?(just askin, no offense) I've seen people put a single filament bulb in there. The contact, being in the center, touches both the running light and brake light circuit. A tell tale sign of this is if your dash lights or front corner lights come on when you hit the brakes.

Other wise check for voltage through the switch and at the taillights. And continuity from switch to taillight. That circuits gotta be open somewhere

[nathan_d]

Alright so after further testing....

 

I have no juice coming into the switch. When i run a wire straight to the switch the brakes work fine. So i guess the question is where the heck does the wire going into the switch come from?

[MilesFox]

like tom said go in the panels and unplug and re-plug all the connections, make sure thay are clean. i have seen this work on jim wood's brat

[flight_of_pain]

i hav had this problem with two different brat tails now, both of them were from corrosion in/behind the small metal socket the bulb goes into. it's a little finnicky to get out(cut the plastic crushwelds) then disassemble and clean. re installation is the same as removal, just use a dab of epoxy in place of the plastic welds.

 

 

isaac

[nathan_d]

Fixed! just said the heck with it and ran a new wire from the fuse box to the switch