I am very glad that I discovered this forum! I came here to learn about installing a new head unit, and decided to pose a question to the community which seems to have extensive knowledge.

For about a year (perhaps longer) I have had an issue with my driver'* side high beam not operating. My daytime running lamps and nightime lighted perimeter are also non-functioning. I changed the bulb on the driver'* side, put a volt meter on it, and tried to chase the wiring harness back to discover a solution.

I spoke to several mechanics and parts store techs, and finally one suggested that my previous usage of SilverStar headlamps may have fried my wiring harness or my Multiswitch.

I would be highly interested to hear is anyone else has experienced this problem with their Bonneville and if there is a simple solution.

Thanks for any help.

2000 Bonneville SLE
138k Miles - I'm running her until she catches fire along the road!

Many many folks have run silverstars in your generation and car w/o a single issue. My feeling would be that there is another issue. Maybe a bad ground or the pin in the main headlight connector at the light itself?

Perhaps its just a bad switch unrelated to the SilverStars. I've read a lot of complaints and advice about a bad headlamp switch. That that a problem on the 2000+ and if so, how would I go about replacing that?

if one SS fried your drivers side I wonder why it didn't do that to the other side, I ran SS foglights and they died about once a week back and forth. My cousin had a 01 Le Sabre and I purchased him some lights off of eBay, the drivers side lowbeam wire actually melted, because of the intensity. Do you use your highbeams often at night? cause they're not fully illuminated at day.

Tore the headlights off and started testing voltages, using the working passenger assembly as a reference. The DS HB is only getting 5 volts in HB mode. For some reason, it isn't even illuminating partially (as it would in DRL mode).

The harness runs from DS headlights underneath to fog lamps and motor fans, and then back to PS headlamps and into the front relay / fuse box.

I ge tthe full 12 volts across the connection at the fuse box, so wiring to switch is assumed OK (correct me if I am wrong).

My best guess is that the wire is fried somewhere in the harness and is shorting.

SO, any guesses as how to find out where it is fried without troubleshooting the entire harness? Harness runs $300 from GM, and I'm not replacing it.

Problem was in fuse box. Took fuse box off, cleaned all harness contacts with electrical parts cleaner and blew off with shop air. Replaced fuse box and tightened judiciously. May have just been a loose fuse box all along.