fuse keeps blowing - corolla tail lights

[sigma]

When i bought my 93 Corolla, the tail lights didn't work. Just a fuse I thought, and i was right, found the offending fuse and replaced it. A week ago, I was informed my tail lights were out again. The replacement fuse had gone. Had a pack of 5 in the glove box so I just put another in 5 minutes ago, turned the lights on and bang, blew straight away. Its a 15A fuse.

So im guessing my car has some sort of electrical problem? Can anyone suggest what could be causing this?

[Alex B]

See if it happens with the stereo turned off, im guessing the dash lights don't work either? Basically if its what im thinking, some monkey has used the green illumination wire an an earth for the head unit.

[sigma]

You are right the dash lights are gone too. Just tried it again with the stereo off but it still blew the fuse. So what is this illumination wire you speak of?

[TRD_ZERO]

Well i had a similar problem with my ep71 turbo. It happend after i removed the rear spoiler then put it back on. I ended up pinching the rear spoiler spotlight wires which cause the rear light to fuse all the time. Although i think my dash lights did work, i dnt really remember. All we did was isolate the problem working back to front.

[Mr.Phreak]

See if it happens with the stereo turned off, im guessing the dash lights don't work either? Basically if its what im thinking, some monkey has used the green illumination wire an an earth for the head unit.

Having the Stereo on or off won't matter, as the unit is generally still grounded, and as soon as 12v ramps up that wire the fuse will blow, you actually have to disconnect the wiring to test if that's the fault.

[matt dunn]

Having the Stereo on or off won't matter, as the unit is generally still grounded, and as soon as 12v ramps up that wire the fuse will blow, you actually have to disconnect the wiring to test if that's the fault.

Correct,

you need to remove the stereo and then put in a new fuse and if the problem is gone get your stereo wired up correctly.

[sigma]

Gotcha, will pull the stereo in the next few days to check. So what is this 'illumination wire' and where does it usually connect to? I was there when we put the stereo in. My mate did it who's done many before, checking the wires with a multimeter. There was no stereo in the car when i got it, just the factory loom that had been cut behind the plug.

[Mr.Phreak]

The Illumination wire is a switched 12v line that dims the headunit display so it's not distracting at night. It's to be connected to the unit's Illumination wire if it has one, if it doesn't just insulate it.

It will measure as a ground normally, but will measure +12v when you turn your lights on.

[solidog]

Is your park light circuit, so u wont have any on the car when the fuse goes, its such a common problem where amateurs have wired the stereos earth to what appears to be a good earth, except when the lights are turned on it feeds that wire and pop goes the fuse.

[Mr.Phreak]

It's not just amateurs who have been caught out by it.

[solidog]

im not amateur anymore! yeah people who don't know! like my old school boss who wired an amp to the aerial switch, no doof doof with cds! i laughed!

[blackmk3]

I did this exact same thing installing a stereo into my mates MR2, found a earth sweet and couldnt understand what the fuse popped when the lights went on, figured out it was the innumiation wire, DOH! lesson learned

If failing that i had a problem with a dodgy brakelight bulb on my wagon, occasionally it would work and other times it would short straight to earth and blow the fuse, new bulb and a clean up of the terminals and she was good as gold again