Did you need to buy a resistor for these led bulbs, or do they have a built in resistor already?  Did you wire the three leds in series to the nine volt battery?  If wired in series, does the coach burn less bright than the combine?  Was the led diffuser a seperate item?  Sorry about all the questions,  Im a bit new, and not to pleased with the wheel wipers on the new combine and coach I purchased.  Looks like Ill have to buy the nine volt battery boxes also.