NA_EJ253

New to the community here, Hi and hope everyone is having a great day.


Quick intro, I own an 08 Impreza 2.5i. Bought 2 years ago. Fog lights were not working since the day I bought it. I figured it wasn't a big deal. However, just recently doing some regular 100K maintenance and wanted to get a working fog lights. I have done the following (in order):

1. Turned on headlights switch then turned on fog light switch. Fog lights indicator on dash did not turn on and fog lights did not turn on.

2. Replaced fog lights bulbs with new Phillips 9006B2. Fog lights indicator on dash did not turn on and fog lights did not turn on.

3. Checked all mini sized fuses under dash (driver side) and under hood. All in great shape, no burnt out fuses. Analyzed using light tester. Fog lights fuse number 29 (15A) and Illumination fuse number 16 (10A) were replaced just in case. Fog lights indicator on dash did not turn on and fog lights did not turn on.

4. Replaced fog lights Relay (OEM #82501AG041). Fog lights indicator on dash finally turned on but fog lights did not turn on.


I belive next step is to test wire continuity. I will use both multitester and light tester. Please let me know your suggestions as to what I need to do next if wires are good or bad.

Also please let me know if I missed a step above, so I can review and fix before going to test wire continuity.


Thank you

Don Clark

Attached are both MY08 and MY09 US Fog light system diagrams (both appear very similar)
It appears for US models the control feed to the fog light relay comes via Fuse 6 (30A) in the main fuse box under the hood (Headlight (LO) relay output), not the illumination circuit.
If all appears good it could be a problem with the BIU.

NA_EJ253

It appears that fuse No.6 on your diagram is fuse No.7 for my car.
Diagram below is straight from the manual in my glove box. By any chance do you have a wiring diagram for this particular car?. What is BIU?.
Thank you for your help

Don Clark

BIU - Body Integrated Unit.

Very strange, both MY08 and 09 US owners manuals, I can access, show the same diagram as you've shown above (note there is actually a fuse shown in position 6)

Even the European LHD/RHD power circuit wiring diagrams show the same layout as I've supplied for the US model.

Here are the corresponding Fuse circuits in the main fuse box as shown on the full US Power Supply diagrams that are available to me

1. ABS
2. Main Fan
3. Sub Fan
4. Empty
5. Empty
6. H lamp Lo +fog relay
7. H Lamp Hi +DRL
8. Map Spot lights, Room light
9. Horns
10. Rear Defogger,A/C control panel,Heated mirrors
11. Fuel Pump
12. TCM
13. ECM
14. Hazards, Key illumination
15. Tail & Illumination

The other two circuits Backup light and Alternator shown on your Owners Manual diagram are located in the fuse box by the drivers knee.

The workshop manual being used for the information supplied shows the following info for Identification (VIN and Applied model)

NA_EJ253

Just re-checked all the fuses under the hood. You are correct, there is a 10A fuse on number 6 (good condition). I also checked again number 7 fuse (30A) and it appears to be fine. I will check wire continuity this weekend. Thanks again

NA_EJ253

Problem solved!. I should have read this before watching a Youtube video. I misplaced the relay, I installed it to the left side of the correct socket. It is currently installed in the correct location (right side as shown in pic). Fog lights are working!.