Park Avenue Headlight Switch Malfunction & Random Lighting

As someone with moderate experience working on cars, I had a very similar issue with my 2004 Buick LeSabre (which shares many electrical components with the Park Avenue). The light switch and dimmer switch were acting up, causing unusual activation of lights and dashboard illumination problems. After dealing with this frustrating electrical problem for a few weeks, I took it to a workshop. The mechanic found that the main wiring harness connecting to the headlight switch assembly had corroded terminals and a loose connection. They had to clean the contacts and replace part of the wiring. The repair cost me 95 Euro and completely resolved the issue, no more unusual light activation or dashboard problems. Before heading to a shop, you might want to check your fuse box for any blown fuses related to the lighting system. However, given the symptoms you describe, it sounds very similar to my connection issue. Could you share: The year of your Park Avenue, Whether the tail lights are also affected, If you notice any pattern to when the problem occurs (wet weather, bumpy roads, etc), Whether you get any specific error codes This information would help determine if your issue matches what I experienced and could guide you toward the right fix.

Latest service was 2 weeks ago at 59701 KM. The headlight switch malfunction seems identical to what I experienced. The mechanic at my last service actually mentioned the dashboard lights flickering but we prioritized other maintenance items at the time. After reading your reply, I checked the fuse box and found two slightly corroded fuses for the lighting circuit. Replacing these helped partially, but the unusual light activation still occurs occasionally. The tail lights work normally, its mainly the front headlights and dashboard lights that act up. The problem definitely gets worse during damp weather. Error code P0617 keeps showing up, which points to the starter relay circuit but could be related to the overall electrical system issues. Would cleaning the wiring harness contacts first be worth trying before replacing the entire headlight switch assembly?

Thanks for the additional details. Those symptoms match my experience exactly, especially the moisture sensitivity and the corroded fuse box contacts. The lighting issues on these models often trace back to the wiring harness connection points. In my case, I first tried cleaning the headlight switch contacts and harness connection with electrical contact cleaner. This provided temporary improvement, but the problems returned within a few weeks. The corrosion had spread too deep into the wiring harness. That P0617 code often appears alongside lighting issues when there are grounding problems in the main harness. The car switch and lighting circuits share several ground points, which explains the correlation. Before replacing the entire headlight switch assembly, definitely try: 1. Cleaning all fuse box connections thoroughly 2. Checking ground points near the front lighting harness 3. Inspecting the tail lights wiring even though they work, sometimes partial corrosion starts there If cleaning doesnt provide lasting results, replacing the harness section like I did might be the best solution. The headlight switch itself was actually fine in my case, it was purely a wiring issue. The labor involved in harness repair is what drives up the cost, but its still cheaper than repeatedly chasing electrical gremlins with temporary fixes.

It's good to hear someone had such a similar experience. I really appreciate the detailed explanation about the fuse box connections and wiring harness issues. The automotive switch problems in wet weather match my situation perfectly. Since both fuses in the fuse box already showed corrosion, I'll definitely try cleaning all the connections first as suggested. The headlight switch assembly is expensive, so starting with the wiring inspection makes sense. I should mention that I tested it again today, the tail lights still work fine but the dashboard lights began flickering more frequently. The P0617 code appeared twice more. I've scheduled an appointment next week to have the ground points and wiring harness checked, focusing on the headlight switch connections rather than replacing the entire assembly right away. Will update once I know if cleaning the connections resolves it or if I need the more extensive harness repair. Really hoping to avoid multiple shop visits to fix this electrical issue. Thanks for helping narrow down the likely cause.