'04 Vue Horn Circuit
 

Attachment 1319I know this topic has probably been beat to death, but nothing I've tried has resolved my issue. My horn circuit stays energized, and the "service something" light on the dash stays lit (little car w/ a wrench in it). It also drains the power to my ODBII port. When I plug in a reader, it won't read. All it says is "detecting data" and eventually fails. Documentation on the wiring harness to the steering wheel seems to be lacking. (pic attached). I need to know which one (or 2) of these wires is the horn circuit. The harness colors, from left to right as you're looking through the steering wheel, are: Tan. Brown. Slate. Blue. Black/White stripe. Red w/ Bk stripe. Slate w Bk stripe. White. which of these 8 wires, or combination of wires controls the horn circuit? I already have an external momentary push btn switch mounted and ready for connection.

Let me turn the picture a bit. easier to see...

On one of my L series cars the wrench light stayed on and the headlights did not work correctly. It turned out that the wrong year headlight switch had been installed before I purchased the car.
That being said the horn is controlled by the bcm and is switched on the can network. Here is a picture of a 2002 L series schematic. If you just want to make the horn work there is a work around. There may be bcm issues or other problems.

Attachment 1472

Try this link

Saturn Workshop Manuals > VUE 2WD V6-3.5L VIN 4 (2004) > Lighting and Horns > Horn > Horn Switch > Component Information > Diagrams

If that is not your engine go to workshop-manuals.com/Saturn and dig around.
The contents in terms of volume of info vary all over the place.

I doubt the horn is wired differently amongst the models but you never know.

If what is on that page is correct, your horn relay may be fried in the on position. Lifting the ground should open the circuit. If that works the horn relay is likely stuck on. The bcm completes requests by providing a ground when commanded to, thus closing the circuit. The positive V pin likely remains at 5 or 12v . So if your relay is stuck closed, the horn will keep blowing until either the relay opens or you lift the ground of the circuit providing current to the horn.

Be careful, I think this is part if the airbag srs system so make sure you don't disable that

Yea, the horn relay is energized, and from I've gathered from this and other forums, each couple of years the dash wiring changed depending on options. The horn fuse does not blow, it's good. My year model (04) was not listed in that manual list, but it IS a handy resource for future reference. Thanks for that tip, any way!

Well,
Sorry that didn't work out.
But what I was thinking w out saying it is that if you want to hook up an alternate hown switch, just put it in series with the OUTPUT of the enabling current (NOT the current that blows the horn) that goes to ground -- right at the relay. This way your horn relay will only be energized when you push the button (which must be a NO (normally open) switch. The rest of the time, the relay enabling circuit will be open and the horn won't blow.

This is of course a workaround until you figure out why the relay it is constantly energized. Really need the right wiring diagram or this will likely not be corrected . Per 02 LW300, if it's triggering the wrench light, the car recognizes something that is not right and it may indeed be a BCM problem.