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Discussion Starter · #1 ·
Ok so been a while since I have put anything on here as FB and social media give us plenty of options for troubleshooting and advice.

So when I turn the hot grips on the back light in the LCD pulses off and on. If I pull the front brake lever in the tacho pulses from idle revs to zero revs in time with the LCD back light. Crazy. Its the same timing as you would see the Oxford grips blue light flashing if the voltage is too low and the grips will not function. This happens when the grips are functioning correctly.

Do I have a bad earth somewhere? The grips are wired earth directly to the battery and positive to the spare connection on the DD headlight wiring so they cannot run with the key off.

Any ideas....

Cheers, Nick.
 

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Sounds like your battery is down on voltage, could possibly be that your charging system is going on vacation.
Had the same thing happen on my old 748 when the stator wires where fired and the bike just ran off the battery.
Turnsignal blinking would make the tach jump from idle to zero in time with the indicators flashing, the bike ran ok at normal throttlem but bogged hard under harder acceleration and just a general electrical nightmare.

I´d start by unplugging the heated grips and see if everyting works.
Then check that your getting a charge from the stator, just put a voltmeter on the battery and the voltage should be higher at 3k rpm then idle, usually the voltage jumps around at idle and stable only when the bike is not running.
 

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It sounds like a voltage drop problem, where does the DD headlights get their power from?
I would check what voltage you have at the DD terminal when it's acting up.
 

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Check all earth points.
With all that going on maybe add another earth (I ran wone to the starter case)
Failing that it could be a slight short in the grips
 

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When you add an electrical load to a weak or undersized battery you will always get a voltage drop across the terminals. The tach needs a constant reference voltage to give a constant reading. Other electrical components need a minimum voltage to function correctly. The charging system will replenish a depleted battery but won't prevent this system voltage drop. Get a new full size/rated battery.
 

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Discussion Starter · #6 ·
Sounds like your battery is down on voltage, could possibly be that your charging system is going on vacation.
Had the same thing happen on my old 748 when the stator wires where fired and the bike just ran off the battery.
Turnsignal blinking would make the tach jump from idle to zero in time with the indicators flashing, the bike ran ok at normal throttlem but bogged hard under harder acceleration and just a general electrical nightmare.

I´d start by unplugging the heated grips and see if everyting works.
Then check that your getting a charge from the stator, just put a voltmeter on the battery and the voltage should be higher at 3k rpm then idle, usually the voltage jumps around at idle and stable only when the bike is not running.
Just put a volt meter on the battery .......arrrgh! I wonder if I could read the voltage from the accessory plug .....Anyhow the bike fires up fine first time every time. If my charging system was on the way out wouldn't the headlight drain the battery making it difficult to start? Bike runs amazing as well.

Just another point, the bike has always since new had the tacho play up when activating the front brake light switch at idle. Pull the brake on and the needle would jump down to zero or close to.
 

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Discussion Starter · #7 ·
It sounds like a voltage drop problem, where does the DD headlights get their power from?
I would check what voltage you have at the DD terminal when it's acting up.
Cannot remember but they are wired as per the instructions from Ducati designs.
 

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Discussion Starter · #8 ·
When you add an electrical load to a weak or undersized battery you will always get a voltage drop across the terminals. The tach needs a constant reference voltage to give a constant reading. Other electrical components need a minimum voltage to function correctly. The charging system will replenish a depleted battery but won't prevent this system voltage drop. Get a new full size/rated battery.
First battery lasted 13 years. Current battery around 1 year old and always on maintainer. Bike doesn't really spin over to start. It fires pretty much immediately. I am going to check voltage from the charging system but pretty sure everything is running well.
 

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Discussion Starter · #9 ·
This multi quote function is not working for me hence all the replies.....
 

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I would be interested in what your charge voltage is at idle. IF your battery is in good condition, I'd ensure that the voltage regulator is allowing sufficient voltage ~13.5 V to the battery at idle and that the stator connections is in good condition. Personally I always upgrade the VR with a newer mosfet design since they are more reliable and more voltage stable.

Also, I'll echo the others on checking all the grounds.

Good luck,
Scott L.
 

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Just put a volt meter on the battery .......arrrgh! I wonder if I could read the voltage from the accessory plug
Yes, you can measure batt. voltage from the accessory plug. Better yet, use the trickle charging plug to measure, since that is usually wired directly to the battery!

The system charges less at an idle. maybe 13.0V as opposed to 14V when above idle. If it were me, I'd be looking at the connector that feeds the RR. The nose fairing needs to come off -- it's above the coolant bottle. If that connector shows any signs of discoloration, cut it out and bypass it. You could triple check by using the fast idle lever, turn on as much stuff as you can (grips, turn indicator, high beam, brake light, heated gear?, etc.)

While this runs for a minute or 2, grab that connector. If it feels warm or hot, it's gotta be bypassed.

FWIW, mine also did funky things with the tach also at idle, with the turn indicators, until I bypassed my connector.

Same with my older ST2.
 
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