Bonneville is FUC*ED

[slowgator]

Ok .. just wanted to make sure it wasnt one of the EFI bikes. Thus eliminates it being a ECU issue.

FWIW, my T100 is a 2007 and does not have EFI, but replacing the ECU* fixed the problem after replacing the coils did not.

*Actually I just checked the manual and it's called an IGNITION CONTROL UNIT (ICU) and not an ECU which is used for the EFI models as Bonafide stated.

 

[thearcticsea]

I replaced the rectifier first before replacing the battery and I ran the bike around and the same thing happened. After that I replaced the battery.

I have to check the battery output at 3k RPM tonight as my multimeter just got here (ordered one online).

Thanks for all the help guys. I need to fix this up as Sunday is supposed to be 61 degrees!!

 

[mark66]

Thanks for all the help guys. I need to fix this up as Sunday is supposed to be 61 degrees!![/QUOTE]

Don't hold your breath on that 61 degrees, not the way it's been around here this spring. :eeek:

Do hope you get it sorted out quick, keep diggin'.

 

[drlapo]

did you check the charging rate with your new meter?

 

[bluesforchallah]

Someone on one of the other forums was having a similar issue with their '04 Thruxton. Here are some things to consider when looking at your Regulator/Rectifyer.

Some helpful hints. Names have been removed to proctect the innocent

The regulator should be fairly warm to the touch. If it leaves burns like you put your hand on a BB-Q, your fucked.... LOL Like I said, I've had instances where they work fine cold, and then take a shit once they get heated up. Check the battery's standing voltage with the key on, but not running. Start it an check the charging. Then get it hot and check again.

A slight drop in voltage at higher rpm's isn't abnormal on a bonnie, though I'd like to see more to be honest. It's sounding more and more like a regulator. You can easily unbolt the regulator to examine the back of it. The rubbery shit should be fairly smooth, and uniform in color. If it has a buldge or two, and hot spots (discolored) it's done. Smell it..... You'll know if it's cooked with a quick sniff. Do a quick swap with another guys regulator if ya can, and see what you're pushing.

These rectifier / regulators are just solid state replacements for the old silicone rectifiers, and a zeener diode, and as on the old bikes, it's the zeener that cooks. Zeeners dump excess voltage to ground. Sometimes they die dumping more to ground then needed. I've seen more then once a regulator that would kill the new battery in about 3 hours with the bike sitting on it's stand, with the ignition off. That's less common. Also less common is the over charging from a bad zeener, but we know that's not the case here.

The next thing you'll be needing to check is the stater. Test the regulator first....

You know the max ACV output @ ___ RPM's, and you know how many watt stator is, so the math is simple.... Max is what matters. Large metal particle build up on the magnets can throw it off a tiny bit, or worn bearings causing a slight elliptical rotation of the rotor changing the distance between the magnets and the fixed windings, so if the max on each leg is close to equal to the others output, and close to equaling the total ACV max, it's generally the regulator. Yes, you can check to see if any of the legs of the stator is grounded to one of the others or the cases, but if it's giving you good numbers running, checking for a shorted stator is a bit redundant. Testing at the battery is not the best place. I've found up to a half DCV drop from the connector on the regulator and the charging lead going into the fuse box with the regulator within 15 inches of the fusebox. Measurable drop from the output side of the fuse to the connection at the battery. The regulator on the bonie is about 35 inches away from battery over all. Great potential for voltage drop by the time it gets to the battery. That's why testing the stator is important. I wouldn't keep a stator that was putting out 10 to 20 ACV less then the max depending on the size of the stator in question. If it's all good, you test output at the regulator connector. The high numbers I tell people to look for can vary a good amount depending on how far the regulator is from the battery. It's generally easier telling folks to test at the battery first being many folks don't know there way around a multi meeter. There's not a thing wrong with that, but I hate asking people how much they know and just help in the easiest way for all involved.

You can quickly tell if you have a short in the charging system by doing a simple short check... remove all the fuses except the one with the charging system, often the main 30 amp. Connect your neg lead to a test light, and the lead from the light to the neg battery terminal. If you get a glowing light, you have a short. Disconnect the regulator, and if the light goes out, you found the short.

Here was his results after replacing the regulator:

Ok, I got the bitch hot!!! Road her 20 miles...hard. Felt up her regulator/rectifier...cold to the touch. Checked her voltage...motor off=12.35, idol at 1000rpm=12.6, 1500 rpm=14.38, 2000 rpm=13.71, 3000 rpm=13.00, 4000 rpm= 12.8.

If it never went as low as your standing voltage, you should be charging ok actually... check at the regulator plug with it disconnected from the harness just to compare, and see what type of drop if any you're getting. A cool regulator is a very good thing.

Side Note:

I haven't had the backfiring issue since it originally happened. My dealer seems to think it was water in the gas. I cleaned the k&n filter pods (i have a airbox removal kit) and removed the inline ball check valve for the tank vent. Just rode 100 miles and it ran perfect.

 

[thearcticsea]

I charged the battery over the weekend but didn't get time to run the tests. I need to read the meters manual and learn how to use it completely, so I'll probably be testing it tonight.

For review :

Test the battery.
Install the battery.
Test the battery again?
Start the bike and test the battery with the revs at 3k rpm.
Write down all info.

Is this correct?

 

[thearcticsea]

My multimeter isn't working or I don't know how to work it. Either way I'm about to rage.

 

[mark66]

My multimeter isn't working or I don't know how to work it. Either way I'm about to rage.

Take a deep breath......now check out the manual and just try the dc voltage mode on the battery. And you know if your sure your setting up correctly it may be a faulty meter and you'll never get it to work right. Happened to me last year. I bought a new multimeter at radio shack, $65, and it never worked....had to take it back for a replacement.

 

[thearcticsea]

It doesn't help that it was bought used on eBay.

I'll get it figured tomorrow. Tonight I decided to just polish some shit needed for the cb450 project bike.

I'm not riding this week anyway. The weather is shit.

 

[thearcticsea]

Okay. Thanks for sticking with me here.

I tested the battery sitting on the bench and it was reading 12.80 volts. I then installed the battery in the bike and while it was sitting there it read 12.20 volts.

I then turned the bike on and it continued to read 12.20 volts.

When I revved the motor up to around 3k the voltage dropped to between 10.20 volts and 11.20 volts. Sometimes when I revved the bike higher than 3k rpm the voltage would drop even further to around 9v.

What does this tell us???

For a refresher I've replaced the battery and rectifier already and these are the results.

 

[thearcticsea]

Tested again and now the battery is holding steady at 12.42 v with the bike idling and even when I rev the bike? wtfmate?

 

[drlapo]

it sounds like a bad diode in the rectifier but you already replaced it, right?
the next move is to disconnect and clean all the electrical connections between the alenator and the battery, coat them with dielectric grease, you may have a poor connection or ground
if that does not do it you will need to check the voltage coming out of the altenator
you need a manual for those tests

 

[nohawk]

Cant the rectifier be damaged if it is trying to work with a bad battery?

I believe he replaced the rectifier before the battery... I could be wrong on both fronts.

 

[drlapo]

my experience is with older BMW's and thay have a seperate diode board and regulator so it's easier to seperate the functions
the symptoms indicate a bad diode in the recitifier but it could be a bad rotor

 

[thearcticsea]

Welp, off to the dealership it goes.

 

[Sal Paradise]

articsea,

you are on the right track... do you need a manual?

+1 on what drlapo said.... clean and tighten grounds, connections.

 

[drlapo]

my 85 BMW had an intermitent charging problem
turned out to be a poor soldered connection on one of the rotor brushes
a simple wiggle aand tug test found it
a bit of solder and 14 volts are back

you never did tell us what the votage is at the battery at 3000rpm

the battery in my 05 Thruxton went "dead" last week; turned out to be an oxidized positive battery cable terminal; a wire brush and all is well

 

[thearcticsea]

Voltage at the battery at 3k was 12.24

 

[roadie]

Well I am very interested in hearing how this turned out. My Thruxton died on me out on the highway the other day. No word from the shop yet as to what it was, they are very busy it seems.

 

[thearcticsea]

The problem ended up being a disconnected wire in the harness.

The rectifier plugs into a harness in the headlight bucket and on the harness side of the connection a wire had wiggled out of its slot.

Simply popped the wire back in and it was fixed.