High Voltage (not the good kind)

[moto fugazzi]

Cruising down the freeway yesterday, and my voltage meters (yes, I have 2 of them) jumped up to 17.1V. I pulled in the clutch to drop the RPM's, and the volts dropped down, then when I released the clutch, the VM went back to 14.1V. This happened twice during a 5 mile stretch, so I think something is starting to give.

 

I have extra grounds on the VR, and the battery connections are tight. Any ideas? Currently, I have the original VR installed, but I have an ESR510 and a used VR as backups. 

 

Before I start diagnosing everything, anybody have an idea on what's wrong? I do have all of Kiwi Roy's schematics and things to test for available on my computer (Thanks, Roy!).

Ken

[docc]

Release, clean, and re-tighten every connection you can get to.

 

Recheck any connection you added (crimped, soldered, screwed, or twisted together).

 

(Not that I ever made anything more dodgy by *fixing* it myself.) 

 

Or maybe evidence of busy Wisconsin winter mice nibbling at the harness?

[Kiwi_Roy]

If the Voltage reference is low the regulator thinks the battery is flat and will overcharge.

I think this is what makes the Ducati Energias fail

 

Check the first two relays for good connections tight / sockets

 

It might help if I knew how your Voltmeters are connected to the bike as in where to.

 

I have a possible solution, that is remove the Voltage reference from the headlight circuit and put it on the ECU relay.

[Lucky Phil]

Im not surprised you saw something odd. With two voltage meters I wouldnt expect anything less.

I think you also need 2 oil pressure gauges to make you riding and ownership experience complete.

 

Ciao

[moto fugazzi]

I'll go through the connections again this weekend, thanks, Docc,

 

Roy, I have one VM connected to the ECU relay, and the other one connected to the cig lighter on it's own circuit. I added the 2nd one last fall since my original LCD VM is too dim to read during the daylight. It wasn't added because I'm paranoid.

 

Phil, thanks for your brilliant words of wisdom. 

Ken

[docc]

Battery condition is also a driving force behind what the regulator/ charging will do (although voltage should never go much over 14.2 if i understand correctly).

 

It is easy to do the full series of voltage tests and assess whether the battery should be conditioned with off-board chargers instead of the bike's circuits. Especially important for batteries that have sat all winter and need "bringing up."

[moto fugazzi]

I've been running the bike for just over a week, and didn't notice any issues until Monday. The battery seems to be fine (according to my crude tests). I took the bike to work today, and experienced the 17+ volts today, and jiggling the yellow wires caused it to return to normal. Maybe a coincidence? 

Today, I reinstalled my ESR510, and was getting voltage readings of 14.8V, and I'm not sure if that's too much for the system to handle. I then checked the ground wire from battery to frame (tranny), and that was coated with tranny fluid (WTF?). I then cleaned and reinstalled, only to find the same 14.8V on my VM. Oddly enough, there wasn't any tranny fluid on the bike other than on the ground bolt.

FWIW, when I had the ESR510 hooked up last year (before the fuse holder melted), I never had a volt reading of more than 14.1V...

Ken 

[moto fugazzi]

Today, my 2 year old Odyssey battery was dead after the bike sitting for about 10 days. I put in my old Westco battery that I charged up last week, and the bike fired right up. VM is still reading 14.8V at 1800 RPM and above.

Time to get the Odyssey tested and see if the 17.1V fried the battery or not.

Ken

[JRD]

Hi Ken- There are several great threads on the Aprilia Forum about charging issues and voltage regulator repair/replacement that early model Milles and Futuras suffered.  I believe the 14.8V is at the high end of the scale but not enough to cook the battery.  Does the voltage drop when the engine RPM increase at/over 3,300RPM?  

[moto fugazzi]

Hi Ken- There are several great threads on the Aprilia Forum about charging issues and voltage regulator repair/replacement that early model Milles and Futuras suffered.  I believe the 14.8V is at the high end of the scale but not enough to cook the battery.  Does the voltage drop when the engine RPM increase at/over 3,300RPM?  

Voltage goes up to 14.8 over 1.8K, and hovers around that at cruising speeds. I don't think it dropped below 14.6V at higher RPM's.

I'll check out the Aprillia forum when I have time, but first I need to test everything with using all of Kiwi Roys files that I've collected over the years.

Ken