Batt died while riding, stuck on road. Help! - Ducati.ms

Togglehead · Jul 4th, 2012, 10:00 pm

Ooooook. So, I have the bike in my sig, and let it sit for three weeks while I was away, and came back to a dead battery. No problem, threw it on the charger and topped it off.

Went out for a test ride and not even 5 miles down the road, the dash lights go dim, and eventually the batt light comes on and the bike sputters and shuts down. I managed to get to a safe spot, but now here I am with no juice.

Dash lights come on dim. Only enough power to kick the bike over once then all lights die.

What could have caused my battery to do that? Bad regulator?

Thanks in advance.

mrturbozxj · Jul 4th, 2012, 11:00 pm

98 ST2? Yep!, Bad regulator is your most likely culprit. Check the output at the battery. If you're not getting around 14v by 2-3k rpm, your regulator is fried.

Check the wiring from the stator to the regulator as well, mine was burnt.

I replaced my regulator with a MOSFET unit from a kawasaki. Here's the thread that inspired me.

finding new voltage regulator to fit ST-2

Bevel Rod · Jul 5th, 2012, 12:20 am

Start by Cleaning the terminals first.

Togglehead · Jul 5th, 2012, 9:42 am

Quote:

Originally Posted by Bevel Rod

Start by Cleaning the terminals first.

Terminals are def clean. Have the powerlet starter wire upgarde kit installed. Just installed a new sprag gear and the thing has been firing up instantly till this.

Where should i check to see if the regulator is bad...right at the batt?

I was able to jump the bike to get it home last night...but it ran like $#!T! Lights went dim and flickered with the RPMS, and bike sputtered like hell. If i gave it some more throttle it would take off then bog down...and sputter...etc. JUST loped it into my driveway, thankfully.

What goes bad on the stator? I was just in there changing the sprag and everything looked normal.

44Dwarf · Jul 5th, 2012, 12:11 pm

First start by charging the battery over night so you know its at full capasity.
then find the molex conector from the sator to the regulator yours is a 98 so i belive it will have only 2 yellow wires not the 3 of the later units but i could be wrong.
Anyway pull the conector apart and Using a volt meter set for AC volts measure the voltage betwwen the two yellow wires from the stator you should have 40 volts AC at idle and 60-100vac with the blip of the throttle. If so the regulator is likely at fault.
See the post above.

va duc · Jul 5th, 2012, 1:19 pm

Ducati had a recal on the 98 stator and voltage regulator. They also changed a spacer between the sprag and the flywheel that had a modified groove in it to sling oil to the top of the stator where they were over heating.

Togglehead · Jul 5th, 2012, 1:36 pm

Quote:

Originally Posted by 44Dwarf

First start by charging the battery over night so you know its at full capasity.
then find the molex conector from the sator to the regulator yours is a 98 so i belive it will have only 2 yellow wires not the 3 of the later units but i could be wrong.
Anyway pull the conector apart and Using a volt meter set for AC volts measure the voltage betwwen the two yellow wires from the stator you should have 40 volts AC at idle and 60-100vac with the blip of the throttle. If so the regulator is likely at fault.
See the post above.

That the big wire thats clipped under the steering bearing? The one that comes out of the crankcase on the stator side?

44Dwarf · Jul 5th, 2012, 2:06 pm

Yes that should be it. Mines a 99 st4 on it the conector is white nylon and has 3 yellow wires your should be just 2 yellows.

t_bare · Jul 5th, 2012, 6:43 pm

Recently I found my main fuse, the big 40amp Maxi-Fuse (next to battery) had best I can tell, vibrated apart. Check that too.

t_bare