Brake Lights & Horn Circuit

[fazz1977]

I've recently been working on my girlfriend's VL calais. One of the last things we need to do to get it on the road is fix the bloody brake lights and horn. They're on the same circuit, I've got 12v at the fuse box but neither work.
I'm really not up for wiring up new ones from scratch. Is this a common problem? The same thing happened on her VK too...

[ucwepn]

I know on earlier models that this kind of problem is caused by a bad earth in the boot area affecting the rear wiring harness but that doesn't really explain the horn hmmmmm.

[fazz1977]

Yep, the whole circuit is down post-fuse box. The weird thing is I think there's a short in there. When I pull the fuse and put the multimeter on there I get 12v on each side of the fuse mount. NOT RIGHT. It should only be on the battery side.

[VRFURY]

i had this prob in my 88 vl but it ended up being bad wires in my actually horn, every time i put a new fuse in tooted my horn it would blow again.

[mag]

Yep, the whole circuit is down post-fuse box. The weird thing is I think there's a short in there. When I pull the fuse and put the multimeter on there I get 12v on each side of the fuse mount. NOT RIGHT. It should only be on the battery side.

Got a test light??

[fazz1977]

Yeah, but the multimeter tells me how much voltage is there.

I did find some crappy towing light wiring in the boot that's just been ripped off. Could be a short there. I'll pull it out on the weekend and re-do it properly.

In short, never buy a mechanic's car.

[mag]

Yeah, but the multimeter tells me how much voltage is there.

I did find some crappy towing light wiring in the boot that's just been ripped off. Could be a short there. I'll pull it out on the weekend and re-do it properly.

In short, never buy a mechanic's car.

Sounds like u found it.
I had some ideas to try if what you found doesn't fix it..

[fazz1977]

On saturday I'll let y'all know how I fare. I'm tipping that that's the problem. Plus I think the horn not working is the fact that the guy who owned the car changed the wheel over and probably never hooked the horn back up. Wouldn't suprise me from the state of the rest of the electrics.

I'll be back here soon posting my findings.
Thanks guys.

[VRFURY]

i also had a prob with my towing cables, but when my lighs where on it was making my indicator flick on and off constantly...

Vl's ar e a pain in the bum lol

[fazz1977]

Ok, here's the scoop. Some total loser had melted the fuse box (god only knows how) and as a result had rewired it. BADLY. I replaced huge chunks of the fuse box and all the fuses and almost everything started working again. The only issues now are the headlight eyelids, the horn doesn't work (but the relay does) and someone re-wired the tail lamps so when the brakes come on the tail lights go out, and vice versa. Should be good in a week or so after I tear out all the crap the the previous owner put in and replace it.

Thanks for all your help and suggestions guys.