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I'm at a loss, new voltage regulator lasted 10 min.

14K views 113 replies 18 participants last post by  jchaplin4 
#1 ·
I'm seriously almost done. I started it up after the alternator was fixed and put back in. Ran beautifully. So came in, thought I was done. Went out a couple hours later. Bike would fire, then die immediately. Checked fuel lines, blah blah. Then thought, well this sounds familiar. Let's unplug the alternator. Bike started and ran but poorly. Plugged alternator in while it was running, it promptly died. So seriously what the fing f f f f f f f f f is going on? I'm done with this problem and want to ride.
 
#5 ·
Or something to do with unplugging/plugging it back in it whilst the bike is running?
 
#6 ·
Is the problem that its a pain to start? I was thinking of going down the same road as you with an alternator. But, if didn't help and your having the same issue I was also thinking of trying the starter relay. Mine has over heated and melted slightly. I removed it cleaned the contacts and it seems to start better. But I think that might be whats giving me my problems. Have you ever blown and melted the 40amp fuse there?
 
#8 ·
It starts fine, strong, no issues. I have never unplugged it while running until AFTER it wouldn't start, so the damage was already done by whatever did it. It will not stay running now at all with it plugged in and runs bad w it unplugged.
 
#9 ·
I hadn't told them yet because it was 8p before I went to leave for a ride and realized I still had a problem. At work today till 3. Next is a new alternator. If that comes off again, a new one is going on as impossible as a job it is to do.
 
#11 ·
Jason, it has been my experience that most EFI system problems are created by poor connections. Not just unplugged, but with resistance in the contacts that creates a voltage drop.
Especially true with the low voltage signal components (most sensors).

The melting relay mentioned above is the result of heat generated by the resistance of poor connections (corrosion, loose female socket).

Don't really know what is going on with your bike, but be certain to inspect every connection you can.

Did the electrical shop test your alternator? Not just replace the regulator/rectifier?
 
#12 ·
Jason, this may sound childish, but SOMETHING is causing regulator (diode) falure. One of the main culprits for this is improper battery hook-up..i.e. reverse polarity...which is very easy to do. Take a picture of your battery as it is hooked into your system right now and post it up.
 
#13 ·
I will get a meter but since it won't run with everything hooked up not sure what it will tell me. The battery has never been completely unhooked, only neg side disconnected during work. Will post a pic though. It just fires and dies, but runs with the alternator unplugged. I will check sensors again. But I did all of that when I was first trying to figure this out.
 
#14 ·
That's an interesting statement there Jason. So is the battery a Koyo? I thought you had said in you rearlier modifications threads that everything had been taken apart...my mistake. The battery has never been out of the bike?
 
#15 ·
Jason, Charge system does not go through the key switch. Get an ammeter and pull the battery neg lead loose, hook the meter in series from cable to battery post and check for key off current draw. High draw would indicate possible shorted rectifiers or regulator. A small draw of +/-1~3 mA is normal (for the clock function and immobilizer if equipped). A major short would blow the main fuse, but a partial shorting of a diode might not and could allow AC current into the EFI system.

Love electrical puzzles, but only when I am looking directly at them with my meters in hand. Good luck.
 
#18 ·
I'm free this week...haha:stickpoke
 
#17 ·
No vacation time available...used it up for the Bubba....

If I get near Louisville on business anytime soon maybe I could just keep driving up the highway to your place. We'll see
 
#19 ·
the battery in it now has been in it since last February. when I disconnect it I just unhook 1 side. so I know but the regulator is in the alternator but is that where the rectifier is also? A bike builder here in Indianapolis told me I should have replaced them both because when 1 goes he has found that the other always does soon after. I am seriously considering just replacing the battery and the alternator. Neither he or I could understand how a loose connection on a sensor could cause something in the alternator
 
#20 ·
Battery under load tested weak. Shot up to 12v when under no load. New battery will be here Tuesday, Alternator/Stater whatever it is is out again, quicker then the first time, (thank god) and will be tested tuesday. If nothing new is found, I have a new one on hold on a shelf in CA ready to be sent to my door. Went over all wires, connections, plugs for a 3rd time, not finding any unintentional grounds or bare wires. Unhooked PC V and will leave it off this time just to see what's up. This weekend weather is tits and there is a ride tmrw. ARRRRGH!
 
#21 ·
What brand of battery are you using? Make certain you put your battery in on its side and the polarity is correct.
 
#28 ·
sorry to hijack the thread but is the battery supposed to be laying down on its lefthand side. as i thought the guy i bought my bike off got the wrong battery and fitted it laying down. my battery instructions say not to lay it on its side, only use in an upright position but its laying on its side.
 
#23 ·
That is precisely what I mean. There are oodles of threads where people have installed their batteries standing up and hooked the pos to the neg and blown up electronics. The battery will fit in a standing up position and allow the reverse polarity hook-up. You are correct in your orientation.
 
#24 ·
i don't think Jason flopped the battery.....
his battery at 12V is definitely on its way out
Ed; i a small mA drain will not pop a diode
i don't see 5 volt sensors fucking it up either

my vote is an intermittent fuck up in the harness......i'd disconnect the battery and connect an Ohm meter between the + side and the engine and start wiggling the harness........
i think the intermittent time is so short it won't pop the 40 Amp just the diode......

the high drain things.... starter, head light, fuel pump and ~ECU.....and ignition depending on the type.....
on a Chevy the HEI ignition needs a 10ga wire for startup only:wtf::wtf:

after typing all this......inspect the starter, solenoid and all the big wire connections they all have the amperage capacity to pop a diode the little shit doesn't

Ed; you are a sick puppy for liking these "puzzles":stickpoke
 
#25 ·
I agree Noel...wasn't there someone on here who found wanter had infiltrated a harness and caused problems?
 
#26 · (Edited)
I am still thinking a problem with the alternator itself since the stator and rotor in the alternator are not in the fused circuits after the regulator. I think you need to get an insulation tester and check the rotor segments and stator windings.

This is a mega-ohm meter....uses a capacitor to drive up to 1000 V through a circuit and measures resistance....marine techs use them to check for fouled spark plugs, they can measure the resistance of the air gap of a good plug.....I use one to look for shorts in coils (like a stator or excited field rotor) that do not show up with a 9 V battery powered ohmmeter.

A modern form of the "growler" that auto electric shops use (or used to use) for these kind of tests.

I don't think there is any thing in the bikes electrical system that would kill the rectifier......maybe you just got a defective part !!!

Noel...I am a sick puppy......

and yes Chuck, there was a thread on water pooling in a low point of a bend in the main harness causing corrosion ad subsequent electrical gremlins....seems it was a common thing on some early 1000s in my memory.....haven't found it yet, but I remember it.
 
#27 ·
Ed;
a long time ago i had charging system trouble on my VW camper.......it had a generator BUT
turn the key on....normal red charging light
start it.....red light dims, rev it gradually red light goes out.....
then it came back on like the motor wasn't running at the switch over voltage for the regulator

rev it to 4,000, same thing, showing total discharge

changed the generator......ever try that on a type 2 without dropping the motor??????:jsm::jsm::jsm:

same thing....

put a meter on the voltage regulator + terminal to battery, key off to ground

like 11.5V on a charged battery

INTERNAL corrosion on the factory molded battery cable:wtf: drove the voltage regulator nuts......and discharged the battery too

generator was fine
regulator was fine
battery was fine

the cable from battery to regulator was fucked

now add an ECU.....that won't run on low voltage:naughty:
and one that sniffs the regulator's ass too

i'm still voting harness glitch

:)

Ed; you're way better at electrical than i could ever hope to be, but alternator/rectifier/regulator combos.....are on 100's of millions of cars with rarely a problem and guaranteed the guy that did Jason's spun it on the test bench
 
#29 ·
Noel, You've stirred my memory up here!! I have searched all the old MV forums and can't find the info.

I seem to remember someone having charging issues with an F4, it turned out to be the wiring loom at the back of the starter solenoid, I can remember the pictures showing the blue looking corrosion
 
#32 ·
Have a sneaking feeling Jason's problem may evaporate upon fitting a new BENCH CHARGED battery... : )
Wouldn't that be grand...:smoking:
 
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