fknay_ryt

I have a 2002 A4 Quattro with the passenger side low beam not turning on. All the other lights appear to work. The low beam error symbol is displayed on the dash. I tried a new bulb and it didn't work. I understand there fuses for each lamp? And I'd like to check those along with any other relevant components. So far I've only found the fuse panel on the driver's side of the dash, but the cover indicates that there is an additional E Panel somewhere along with some relays. I can see four relays behind the fuse panel, so I'm assuming those are the only ones?

Where are the rest of the relevant components in the circuit for the passenger side low beam lamp?

fknay_ryt

BTT

lyleswk

It is fuse number 20; should be noted on the cover. Don't know anything on the relays...

Redd

Without knowing the A4...normally headlights are powered through a relay in order to provide higher voltage (no voltage losses from long thin wire runs) and brighter light.

Interior Fuse Box Location: 2002-2008 Audi A4 Quattro - 2002 Audi A4 Quattro 1.8L 4 Cyl. Turbo indicates there is only the one fuse panel in your car.

VWVortex.com - Audi A4 Fuse Box Diagram
has a diagram and confirms fuses 20 and 21 are for the low beams, apparently without relays.



You can physically test a fuse without even removing it from the sockets. On these ATO/ATC type fuses, if you look at the top of the fuse where it says * 20A * or other rating, you'll notice a small hole in the plastic, where I've shown asterisks, and a bit of metal in the bottom of those holes. Those are intentional test points. If you take a cheap $10 multimeter with thin or sharp probes, put it on the 20VDC scale. Connect the black lead to a ground (i.e. stab it into some bare metal) and then stick the positive (red) lead into each of the holes in the top of the fuse. One side should always show "12" volts, assuming the ignition is on. The other side will show the same "12" volts if the fuse is good, and zero volts if the fuse is bad.

There are handy test lights, under ten bucks, the size of a screwdriver, that can be used the same way. They light up if there's twelve volts, they don't when there's not. And they don't need an internal battery.(G)

There are also ATO/ATC fuses that have little red LEDs built into the top of them. If the fuse blows, a little current still goes through the red LED, so the blown fuse literally turns on a red light to show you which one is blown. Available from a lot of junk sources, all the auto chains, and also from Littelfuse (a fairly reputable company) on Amazon and such.

I wouldn't go run to replace all my fuses with them, but for important and awkward ones...not so crazy to make life simple.(G)

If the fuse to your headlight is good, the same $10-20 multimeter can be used to see if the voltage is actually getting all the way to the headlight. Could be a broken wire in between, or a bad switch contact, or a broken ground contact on the "other" side of the headlight. Although almost all headlights, except Toyota, are grounded right at the housing.

Iris Ovato

i hava a question can anyone help me please.. i have a 2011 a4 audi but i need the diagram for the fuses box that is located by the windshield passenger side ..

lyleswk

You actually have a B8, not a B6, but assume the layout is on the fuse box cover. Is it not?

Db1312

Use
My friends a4 says that there should be fuse at 20 and 21, but there's no wiring to there and yet the lights work. Any thoughts?