Audi Repair: 1999 Audi A4 Headlight Issue, high beams, micro central

Question
QUESTION: Hello! I have a 1999 Audi A4 1.8l. When I recently went to start it up, the car started fine, but the headlights (both low and high) would not come on. The wipers, front turn signals (rear work fine), environmental air blower and horn also stopped working. I can get the high beams to come on if I hold the light switch lever to the high beam position. However as soon as I release the lever, the lights go back out. The car has been to a mechanic where they replaced the headlight switch assembly on the steering column. That did not help. They have checked the ignition switch and did find a burned spot on a contact which they cleaned. That did not help. I saw your suggestion to another question that was similar to my problem where you suggested to check the Load Reduction Relay. They found another relay in the car that had the same P/N as the current Load Reduction Relay and that did not work. Jostling the Micro Central Electric Panel does occasionally cause everything (high and low beam lights, wipers, etc.) to work if the high beam switch lever is pulled to the high beam position. However, everything does stop working as soon as that lever is released. This may work again depending on if the jostling results are still in effect from before (it may work or it may not).

I would greatly appreciate it if you have any ideas on where to try next. Thanks very much in advance for any help that you can offer.

ANSWER: Hi,  If you have already changed the load reduction relay, it may be that the main power line onto the fuse box has a bad contact.  Usually if moving something causes a change in the behaviour, there is a bad connection somewhere.  Carefully check all the red lines into the electrical panel.  I am not sure if the mechanics found another relay, did they replace the actual load reduction relay, or not?  Let me know,  Jan

---------- FOLLOW-UP ----------

QUESTION: Hi Jan,

Thanks very much for your time and suggestion. I have passed along the information to the mechanic and they have given me additional information. They have noticed that "half the fuse panel doesn't have power". The person that I spoke with didn't know exactly what fuse numbers that encompassed. He did say that the lights and wiper fuses were included in those that did not have power. Also, they found the relay in another part of the car that had the same P/N as the Load Reduction Relay, pulled it from there and switched it with the Load Reduction Relay. They said that it did not work. They also said that one of the posts on the bottom of the Micro Central Electric Panel did not seem to have power, while all of the others do. He said that it appears that line goes directly to the fuse panel. Not sure if that bit of information helps at all.

Thanks again for your time and help. Please let me know if anything else occurs to you for us to check.



I will let you know what they have to say about the red lines into the fuse panel.

Answer
The load reduction relay should be the one furthest to the left under the dashboard.  Rather than switching relays, they should put in a known good one.  It supplies the fuse panel with power when the ignition is in the on-position, not when the key is in the start position.  Let me know what they find,  Jan