I read on another site that some guys were having the same issues-they bought the "relay" harness-their problems were solved.I can't say either way.I do know that when I bought my FIRST set of Xentech's-the instructions stated to "run the lamps for about 5 minutes" on FIRST LIGHT UP.I did not see that in the DDM instructions.Could be what causes the lamps to intermittently not light up?I redid my connections on the stock connectors(Blue and Green ones)by inserting the leads of the bulbs straight in to the connector-instead of using the "plug" connector.Then once they were all lit,I siliconed the connectors so they wouldn't vibrate loose or anything.That solved the lighting problem for me anyway.It wasn't the ballasts-it was the connectors at the stock plugs in the stock harness.











....NOTHING connects to your battery-so they're trying to sell ya a relay harness.What problems are you having?There should be NO open wires at all.All connections should come with a plug on them.It's possible with all the complaints from customers about the plug connections not working well that they left the plugs OFF of the ground plug lines to make it easier to install so it would work better.Maybe that's what you have?Any pics would be good.IF THEY HAVE ALL LIT UP,whether one by one,or any combo,the ground is okay.Now-they should NOT shut off your engine.SOMETHING is very wrong there.If your grounds are correct-the lamp will light.The finicky part I had with mine was the connection at the stock lamp plug-the blue one and the green one.BOTH of those would not connect well with the DDM plug on there.I had to remove that plug,and insert the lead down into the factory connector and silicone them in there after I had them lighting.(not while they were on of course!)Another thing DDM does not say-but another company DID say-was when you FIRST install and turn them on-let them stay on for at least 5 minutes to fully "burn in".They don't need to be in the factory headlamp socket to come on once your wiring is correct.They can be turned on "outside" of the bike,just hanging there on the sides.Then after ya get em going,install into the headlamp receptacle.(with em turned OFF of course).If yer gonna check em that way....DON'T allow em to sit against your fairing-you will fry a hole in it!And don't EVER touch the glass portion of the bulb with anything-finger prints will cause the bulb to fail early on.If you already have touched em,best to use a soft cotton cloth to wipe em off-no paper towels or anything that would scratch the bulbs.And be careful about installing as well-that you don't scratch the bulb when you first insert it into the metal factory socket.You just turn the bulb plug in the socket till it tightens up,and it will give you a little kind of "click" feeling as it locks in.It MAY not do that either,but when it's snug in the socket,don't keep cranking on it to get it to lock in-you'll snap the leads in the black shrink wrap connection there.(if it has the connection-to-bulb that way).If it's a regular plug connector,you should have nothing to worry about when locking it in to it's socket.