Originally Posted by copperhead1861
Noticed both Hi/Lo bulbs out and the switch indicates a constant Hi-Beam. Replaced bulbs, checked fuse and discovered there is no specific relay. All other electrics are fine. I'm a horrible automotive electrician, but I suspect I'll need to check the headlamp switch and thereafter wiring.
Am I missing something embarrassingly obvious?
The bike is currently naked (sans fairing and fuel tank) and is awaiting me changing the oil, air filter and general PMCS. I have also removed the battery given its unknown age. The bike was purchased used, last year at 34,000 miles and now has about 39,000.
You already got the hint where to look from H96669 post.
This is a fairly common problem and a design weakness (in my opinion) of the headlamp assy for K1200RS and K1200GT of 2003-2005 (given your symptoms: both bulbs "appear" to be out with constant high beam indicator on dash)
Very difficult to repair the wiring inside with lamp assy on bike - not much room to view and work. At the end of each Brown wires (ground) there is as a Spade connector. You should be able to pull the connector using a long-nose pliers. At the end of one of the 2 brown Ground wires, near the connector, will be damaged (burned) and the connector will look a bit damaged too.
BMW does not sell parts - only a unit. You will have to do some wiring and welding (been there, done that...). Some have welded both Brown wires together in the middle so as to have only one spade connector going to copper part (basically 2-into-1).
The problem seems to be most common under either OR both conditions:
- A higher wattage bulb than specified has been installed (Low H7 or High beam H3 should be 55 watts max each ),
- The bike is ridden for LONG PERIOD with the high-beam active in fairly hot weather (too much heat generated inside the headlight casing)
The most accepted theory is: a combination of a few weak items (minimum gauge brown wire - thin connector) and too much heat inside, causes the connector to expand and contract (heat followed by cooling cycle when you park). As this happens, the connector gets a bit loose, resistance increases, cause arcing. This arcing is easily confirmed by the condition of the old connector.