I'm getting ground continuity at the bnt fuse with the room 7.5 and the stop 20 fuses plugged in. I removed the front harness to paint the bay and when I put it all back together the problem started. Everything worked flawlessly before. Any ideas on where to start checking? The fsm isn't a whole lot of help or maybe I'm just wiring diagram retarded. Any help would be greatly appreciated.

 

How are you checking for continuity to ground? An example would be the w/the meter set to continuity (obviously) you would place one meter lead to a wire in question and the other meter lead to a known ground source and if the meter rings out then you know the wire in question is grounded.

Is this an S4 or S5? Assuming it's an S4 the BTN fuse powers the illumination, antenna, hazard, heater, defroster fuses in addition to the two you mentioned thus if White/Red wire from the BTN fuse is grounded accidentally then all the fuses just mentioned would all be grounded as well. So, which wire did you test for continuity to ground? Was it the W/R wire or some other wire?

When looking at the wiring diagram look at the "power system" diagram located towards the front of the file and it will illustrate how the BTN fuse powers these fuses as well as which wires receive power from these fuses. Example, the room fuse powers the Blue/Red wire and the stop fuse powers the Green/White wire and so on.

And the BTN fuse should be pulled when doing these tests because the fuse provides constant power to the W/R wire and associated fuses and the wires powered by these fuses.

 

I knew you'd chime in Sooner or later. It is a S5 convertible and I'm checking continuity the correct way. I'm chassis swapping the car at the moment with an sr20 that was in my other s4 fc. Currently the plug from the dash harness that goes to the ecu is unplugged. I know the room fuse has a single wire that goes to ecu. Not sure if that helps.

 

You're putting an sr20 into the vert? And what is the wire color of the wire coming from the room fuse that you say runs to the ECU, and what pin does it go to (is it Blue/Red and goes to pin 1A). And is it the wire running from the BTN fuse to the interior fuse box which has continuity to ground?

 

Nothing is plugged into the ecu at the moment, I was just mentioning that stock I believe a wire protected by the room fuse provides power to the ecu. I pulled the green long plug and the white square plug from the kick fuse box and got no more continuity at the btn fuse. I believe the white plug is the stop 20 fuse and the green plug is the room 7.5 fuse. I'm getting ground continuity with 5-6 wires in the center bank of the green plug and on only 2 wires on the white plug. Having trouble finding the color codes for the wires but will write the colors of the wires I'm getting continuity on and get back to you.

 

I'm not really familiar w/the plug colors but more like the # of wires in the plug plus the wire colors in the plug and that tells me what plug it is. Also, you could use the wiring diagram to identify its name.

 

Ok I'll do my best to figure out the diagram. Thanks satch!

 

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this is where im getting a ground signal. when i unplug these 2 plugs with room and stop fuse still plugged in the ground continuity at the btn fuse (white/red wire) goes away. there are 3 plugs plugged into the kick fuse box, 2 green long rectangular plugs on top and bottom and a white square plug in the middle. these are the top 2 plugs.

 

on the green plug im getting ground at the green/white, green, gray, blue/red, and black/red wires. on the with plug im getting ground at the black/red, yellow, black/blue, and gray wires

 

The G/W wire is powered by the stop fuse which is powered by the BTN fuse. The G/W wire runs to a 2 wire plug at the brake pedal. The two wires are G/W and G. Unplug this plug. Now if the G/W wire in the Green plug you supplied a picture of has a ground on it then the items which the G/W wire supplies must be grounding it out (at least one of these items). Make sense? Say yes. So, w/the stop light plug unplugged then check the G/W wire to see if the continuity to ground exists on the G/W wire (not continuity to ground on the W/R wire at the BTN fuse, but on the G/W wire). If you still have continuity to ground on the G/W wire then you know the ground source on the G/W wire is not coming from the stop light switch unless the wire itself is exposed and coming in contact w/a metal ground before the wire reaches the 2 wire stop light plug at the brake pedal.

Now the G/W wire also feeds a plug at the CPU that is for the horn relay. The plug has from 6 to 7 wires and not all pins in the plug are used. The G/W wire is at the end of this plug and next to a G/O wire and above a G/R wire. So, unplug this plug if the above testing of the stop light plug did not help. W/the CPU plug unplugged do the same test to the G/W wire to see if there is still continuity to ground on the G/W wire.

If the continuity to ground continues to exist then maybe the wire (G/W) feeding the CPU plug is exposed to a ground as it runs from the fuse box to the plug itself. Now the G/W wire also feeds the cruise control unit which has many many wires. So, unplug it and follow the same test for continuity to ground on the G/W wire.

And page 21 of the wiring diagram details all the fuses on 1 page and shows which wire is powered by the fuse and which components the wire powers. Look at it and it will show the stop fuse. It will show the fuse powers the G/W wire. It will show that it powers the stop lights, horns, cruise control and the shift lock actuator (autos only).

 

Figured out the room fuse ground. I unplugged the bulb for the trunk light and unplugged the door sensor and the ground went away. Weird. Will get to the stop fuse tonight. Finally found a good online source for an s5 wiring diagram And it's helping a lot thanks again satch.

 

can you post a link to the s5 wiring info?