Clean off all the connectors on the base of the h1 bulb (and, since you have aftermarket headlights, the connections between the stock harness and the headlight).
What wattage H1's are you running?
If you want to try to isolate the problem, get two 9006 bulbs and plug them directly into the lowbeam harness. If you still get LBF after that, you have further wiring issues.
Hot: 2001 Estoril M Roadster
ZCP 19's, ZHP knob, JL 8W3
Cold: 2002 TiAg M3 6mt
ZCP 19's supersports, ZHP knob, UUC short shift GROM, OEM 18's w310's,
http://absolutehid.ca hid kit