Smart Fortwo Random Light Activation Fix Needed

Had similar electrical problems with my 2009 Smart ForFour CDI. The headlight switch was actually not the main culprit, it turned out the dimmer switch wiring harness had deteriorated connection points causing intermittent electrical problems. The dashboard lights showing errors were the first warning sign, followed by unusual activation of car lighting systems. The root cause was corroded terminals in the main wiring connector block under the steering column. This required removing the steering wheel cover to access the connection point. This is a known issue that gets worse over time if left unchecked. While not immediately dangerous, faulty electrical connections can lead to more serious problems if ignored. The repair involved cleaning the connector terminals, applying dielectric grease, and replacing some damaged wires in the harness. Would suggest having a qualified technician diagnose it properly since electrical problems can be tricky to pinpoint. Testing the headlight switch alone may not reveal the full extent of the wiring issues.

Thanks for sharing that experience. I had similar headlight switch and wiring issues with my Smart Fortwo last winter. After reading your description, it sounds exactly like what happened to me, unusual tail lights activation and dashboard errors. The connection problems in the fuse box got worse over time just as you described. Can you remember roughly what the repair cost was? Also wondering if you have had any other electrical glitches since getting it fixed? My mechanic mentioned I might need to replace additional wiring components later.

Since my last post about the Smart ForFour electrical problems, I got the repair done and can confirm the faulty light switch issue is completely resolved. The repair cost came to 95€, which covered fixing the cable and plug connections that were causing the problems. The automotive switch repair has held up perfectly, no more unusual tail lights activating or dashboard warning lights appearing. The mechanic did a thorough job checking the fuse box and all related wiring while they had it apart. They found no other potential electrical weak points that would need future attention. This common electrical gremlin often gets misdiagnosed, but once the correct connection points are properly repaired, the headlight switch and other lighting controls should work reliably again. The key is having a technician who knows where to look for deteriorated wiring in these models. Good news is that since the repair six months ago, all electrical systems have functioned normally with no further glitches or warning lights.

After getting your feedback about similar issues, I finally went ahead and had my Smart repaired last week. The electrical problem turned out to be exactly what you described, corroded wiring connections near the dimmer switch assembly. My repair bill came to 120€, slightly more than yours since they also replaced some damaged wiring in the tail lights area. The mechanic I chose specializes in electrical diagnostics and actually showed me the deteriorated connections before fixing them. The light switch and all dashboard controls now work perfectly, no more unusual activations or warning lights. Really glad I got it sorted before winter. Should have done it sooner instead of worrying about my previous bad experience with that other shop. Thanks again for helping me understand what was likely causing the issue. Having that knowledge made me more confident in getting the right repair done.