Brake Lights blowing fuse

[Dogo]

It was noticed on the melb cruise that my brake lights werent working. we found out that the fuse was blown. Every time I replace the fuse, it blows again.

Any suggestions on what could be causing this ? I'm going to look into it today, but any advice would be much appreciated !

It seems that the fuse is fine until the car is started. ie I can use the brake lights when the car is off, but when i start it, the fuse fries as soon as I touch the brakes.

It was also mentioned that the cig lighter is attached to the brakes as well. Is this true ? I do have some other things on the cig lighter wire ( mp3 HD and DVD player ) But the fuse still blows even if these are switched off.

thanks!

Dave

[Cosmo Dude]

It was also mentioned that the cig lighter is attached to the brakes as well. Is this true ? I do have some other things on the cig lighter wire ( mp3 HD and DVD player ) But the fuse still blows even if these are switched off.

Dave

I was wrong about the lighter remark.
It's a bother but what was the last thing have done to your electrics? I made a mistake once connecting an earth to a light circuit (only 3 ohms, nothing realy).

Rod

[Dogo]

still no luck :(

I have worked out that it doesnt matter if car is on/off/acc , it blows anyway. I removed the rear lights to find that there are no visible problems or water contact. Although there is a little bit of water in the area. that just seems to be the way mazda designed them - they sit right where the water drips off the 'boot rain tracks'.

I removed the bulbs and it still blew. The roof brake light was on tho. The bulbs had a bit of white crusty stuff around them but otherwise looked ok.

I wish i knew how long they've been out for ! Last thing I did was attach the dvd player. Which uses wires from the centre console. I think the brake lights run down the side of the car. I did make use of some wires went to 2 plugs that didnt hav enything plugged into them. They're right under the hand-brake.

Where would the sensor that the lights run off be ? on the actual brake ? or would there be a sensor on the pedal ?
I recently had my brake discs/pads replaced too ...

any idea as a temporary measure would it be ok to find fuse strength that didnt blow ?

I'll keep trying. thatnks for ur help so far.


Dave

[Pernod]

Check out http://www.geocities.com/lantishatch for a wiring diagram.

You can see that both the cruise control and air bag modules also run off the brake circuit (if you have these). Prehaps it could be a problem here?

If you have done anything to your horn then that would be where I would look first?

What is strange is that you said the top lights are still going, as these are on the same circuit set?

I wouldn't recommend running a larger fuse as this is likley to lead to further problems. Although check that you are running the right size fuse. Should be 15A i think.

[JynX]

Sounds like a short cicuit but its weird it only happens when you have the ignition on as the break circuits arnt wired into the ignition. Id be inclined to agree with the horn idea as the break circuits are pretty well hidden from memory.

Putting a bigger fuse in is a bad idea. Get a sparky to look over it.

Cig lighter is not related to the break circuit. Its wired into the radio circuit which has a seperate fuse.

[Dogo]

some mis-understandings :

What is strange is that you said the top lights are still going, as these are on the same circuit set?
no what I meant was that the top light was still connected when i tested it with the side brake light bulbs removed. in this test the fuse still blew, and so the top light didnt work when that happened.

Sounds like a short cicuit but its weird it only happens when you have the ignition on as the break circuits arnt wired into the ignition
I found out I was wrong. The fuse blows regardless of the ignition being on or off.

I have worked out that it doesnt matter if car is on/off/acc , it blows anyway.


Thanks, I'll take a look at that wiring diagram ...

I cant really take the car to a sparky coz there are so many other wires etc running thru the car coz of my stereo etc. Its hard for even me to find my way around and I put them in!!

I'll try undoing all the changes recently made ( dvd etc ) and see if that fixes it.

[Dogo]

odd. the wiring diagrams say the horn is on that fuse too.

but the horn still works !!!

:shock:

[Pernod]

hmmm. The wiring diagram is for '95 and later, but I have found it to be close enough for my 93 Lantis...

Prehaps this is one of the subtle differences?

[Dogo]

hey, fixed it !

it was caused by the dvd player running a ground to one of the plugs under the centre console.

Any1 have an idea what these do ? 2 white plugs going no-where in my car. Maybe they're for the auto models. park sensor etc. or maybe they're for those lucky bastards with a sun-roof. hmmmm

[JynX]

Why on earth did you run a ground to a plug???

Heh kinda funny though.

[Rupewrecht]

i think they're the plugs for the sunroof controls, if they're under the centre console...

[Dogo]

Why on earth did you run a ground to a plug???
yeh it was pretty stupid. late at night, in a rush, in the dark. y'know :D

i found a constant 12v , and used its +ve and -ve wires.
hey, it worked . pity the brakes wouldnt , but i could watch dvds !!

LOL

[mrpayner]

AAHHH!!! Could the great mystery of the white plugs be solved....

http://www.amihotornot.com.au/album/photos/18162-2003630125214.jpg

I wondered what these were for as well...

Adam

[Dogo]

WOW thats sooo clean and .. well ... empty !!!!

u should see that area in my car. wires everywhere! hehe tidy tho. not a messy tangle.


I thought they might be for the sunroof too. That or auto transmission. Maybe in the depths of the astina wiring diagrams we will find out :)