Ok I'll detail the symptoms:

I'm switching from s4-s5 black interior. Going pretty well till i start hooking things back up. I hooked up the gauge cluster and ran a new ground from the "chain of wires" that origionally screwed into the old metal frame of the dash. Since the new one is plastic, it's not there anymore. While i was wiring this one up the horn just... went off... and it didn't stop going off. So I disconnected the horn and tried to start it, and it blew a 10 and 7.5 amp fuse. Something about interior lights not sure what the other one is. And, it doesn't start now. as a matter of fact in order for anything electrical to work after you try to start it you have to disconnect and re-connect the battery.

Things i've removed: AC core, Blower motor, logicon, idiot light cluster.

I've only got the gauge cluster hooked up right now. and the glovebox light.

Also the horn isn't hooked to anything right now, the situation didn't change when i plugged the steeringwheel horn button back in.

I'm thinking that this MAY be related to the idiot lights not being connected to anything because i do know that alot of wires run back to that according to the wiring diagram.

Any help here is greatly appreciated.

 

Well the car not starting problem was related to the battery being dead. I unplugged the gauge cluster, and voila, no more horn going off.

I'm gonna look into more problems with grounds.

wish me luck

 

Ok well a little more investigation shows that now the gauge cluster does not work, and the lightswitch now turns the horn on as well as the lights :P go figure. Well i think i fried something. I'm going to consult Icemark as to what exactly is the problem, I suspect the ECU.

-Mike

 

ECU controls the engine... doubtfull that it is related.

Did you use the S5 harness or your old S4 harness, and are you using a S5 cluster with a S4 harness?

Pins would need to be moved if you are crossing series electrically.

 

No, I'm keeping all of my s4 electrical components. And i'm relocating the idiot lights.

You Mentioned something about the light switch/wiper switch controling the horn? Perhaps i misread... the idiotlights control the horn?

 

Oh Btw, I completely removed the blower and AC core, Heater core is still there however.

 

The CPU controls the Horn, turn signals/hazards, key lights, warning buzzer for keys and lights.

It has nothing to do with the wipers or wiper switch.

The idiot lights also have nothing to do with the horn.

When you say you are relocating the idiot lights, what are you doing?

 

Well I'm using the S5 idiot light surround. I'm going to relocate the idiot lights to a different section of the dash, Not sure specifically where. I'm going to integrate either a radar detector or a graphic equalizer where the surround is. Just trying something diferent. I'm not exactly sure of what will go in it's place. The idiot lights will probably go where the logicon is.

Ok, So the CPU controls that, is that the part you said that you do specific repairs upon? Would it be a root of the problem I am now having if it is not grounded or grounded insufficiently?

 

the CPU only controls the alt failure warning signal, to the idiot lights.

If you have a bad CPU, yes I can rebuild them, and if you have a bad idiot light/clock assembly I can repair those. But if the cars wiring is the issue, there is little I can do then until the wiring is fixed

 

Is there a diagram that shows each plug and it's uses along the chain that runs from one side of the dash to the other?

 

marking this one for reference.

PJ

PS-- My problems started when I grounded those black wires on the dash harness to the dash frame (metal). Maybe they weren't grounded in the first place...

 

OMG Same exact thing happend to me!!!

 

were are these black wires that you guys grounded?

Not all the black wires in the car should be grounded. If they were not connected to ground then you should not be grounding them yourself.

 

See, the thing is that those two black wires have ring terminals on them... they are side-by-side to eachother, as if they were intended to mount to the same position. The only thing nearby for them to connect to is a solitary machine screw on the metal dash frame which has no apparent purpose. It does not hold anything down-- no clip, no plastic, no nothing. That is why it seemed natural for the terminals to ground on it. I wish I had taken pictures of the harness on the dash frame before I took it off. Maybe I will pull the dash out and take pictures. It looks to me like I will have to disconnect these ring terminated black wires.

PJ

 

No, if they have ring terminals they are grounds... do you know where they are coming down from???

 

when you push the horn, isnt that when it gets grounded? metal from horn hits metal on wheel? just a thought.

 

They are coming from the main harness that runs across the dash right on the drivers side of the console.

PJ - I unattached the grounds from that same mount on my s4 dash. I was attempting to reground them on the center console with a little smaller gauge wire, gauge 14. Thats when my problems occurred.

 

Sounds like a simple repin issue, hunt down a FSM and go from there. Hopefully no components were damaged.

14 gauge should be sufficient grounding, as long it's not very long, and has a solid connection to the chassis.

 

Define Re-pin

 

Here's a pic of the two ring terminals behind the dash. The wires are black with brown stripes.



Another cluster of wires with the same colors meet in the terminal illustrated below.



As you can see in the next picture, there is a jumper connecting all the grounds to eachother. This terminal was wrapped in insulation on the main harness behind the glove box.

 

I know I am addressing more than one problem, but my main concern is getting my driving lights and interior lights to work again. The way I am looking for the problem (until the FSM finishes downloading) is by checking for resistance between my illumination fuse socket and ground. As of right now, there is no resistance, indicating I have a short somewhere. Unscrewing the ring terminals did nothing. Taking the jumper out also did nothing.

PJ

 

I might as well explain when the problems started. When I had my dash out, I wanted to see if I could start the car without the idiot lights, logicon, etc. plugged in. The car started fine. While the car was running, I grounded the terminals against the dash frame and that's when the horn went-off. I am not sure whether this caused my lighting problem since I did not notice it until later.

The problem is not in the switch, since I blow fuses with it unplugged. My harness is in toasted shape, but I pulled the pin out and there are no shorts withing the harness. My oil pressure gauge also ceased to work.

I just thought I would sum all of this up.

PJ

 

Can you confirm that they are black/brown???

Not black/red or black/faded yellow???

I am trying to trace down the color, but have been unable to find Black/Brown listed in the car.

Either way, Grounds are only black on the FC

 

They aren't really "striped." More like ribbed-- every 1/2 inch or so. The color may be an old red-- looks brown, really. It has to be a ground. I just can't figure out why the horn went bonkers when it got grounded with the car running.

PJ

 

I am thinking (and have not researched to back it up yet) that it may be the cruise control horn feed.

The S4 factory cruise had a horn input to disable the cruise (if you were driving with the cruise active, and honked the horn it disabled the cruise until you reactivated it).

let me do some work and see what I can find.