08 XB9SX VR/Ground issue

[andrewlind87]

Over the last few thousand miles I have had the same reoccuring problem on my bike. I will be riding along and all of a sudden the headlights will dim, the bike rpms will drop, and I get an engine trouble light. Code 1-6, low battery voltage. Over the last few years I have tested the voltage regulator (VR) and stator, as well as replace both of them, in the case of the VR I have replaced it multiple times. I have bought a new battery and installed a charging system into my panniers so I can always start from a fully charged battery yet still the problem persists. I have installed a DC voltmeter that connects to my headlights. It reads 0.5 volts lower than battery voltage and usually shows around ~13 volts. When the problem shows up it drops to ~10 volts, lower than battery voltage. This is making me think that it isn't the VR at all, but rather an intermittent ground.

Do the XB's have a known ground issue? How do I perform a ground isolation when the ground ONLY comes in when I am riding? What are my options other than hitting this blasted thing with a large hammer until I feel better?

[50dro]

Have the seat rails ever been painted/coated? I had a similar issue after powder coating my rails. The engine, frame etc gets the ground through around the seat rail mounting bolts. In my case, the starter wouldn't turn, then even if I bump started it, it gave me issues. This is how I tested it:



I jumped the main negative terminal to the engine ground point with standard jumper cables. When I did, it fired right up. I cleaned off the coating where the rails touch the frame and it ran like a champ!

Good luck!

PS - My bike ran OK for nearly a season. My guess is that it got a "good enough" ground through the bolts at first...

[WIGGLE2]

Did you clean, inspect, and / or repair the #77 connector behind the front pully (sprocket) cover? I had the same issue. It was starting to corrode some. I cleaned it up good, packed it with dielectric grease, and it's been fine since.

[user_deleted]

^^^^ this. what rick said. check the connector which is behind the plastic front sprocket cover. also check the positive battery cable connection at the starter assembly.

[andrewlind87]

I have never had it powder coated, so I am not sure about the first recommendation. I see you had pulled off the airbox for that. I had done an open airbox conversion, could there be a short there? It's an '08 and I'm told there is no 77 connecter on the '08 and latter bikes.

[Negative]

They changed the type of V/R on the later bikes I believe ... I think it's a single phase instead of a three phase .. As far as the V/R failures, how fresh is your battery? ... I've seen a few threads where people ran a totally separate ground on the bike and that seemed to improve/eliminate a few electrical quirks ... I'll need to search around for that ... My 03 XB was doing this EXACT same thing not too long back ... But I replaced my V/R connector with the updated one and it fixed all of that ...

[andrewlind87]

So I swapped the relays around and the problem changed. I no longer got intermittent low voltages, rather the bike died and the fuse for the fuel pump burned out. I swapped it out and am going to order all new relays. Wish me luck gentlemen!