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How do I check my Alternator?

23K views 21 replies 9 participants last post by  alienbeing 
#1 · (Edited)
I have an '06 speed triple, I took it out for a ride today and after an hour I stopped for a light and when I engaged the clutch the bike stalled. To make a long story short I got stuck and when I got the bike home there is no juice flowing into the battery from what i can tell and the bike is running purely off the battery juice. How do I check to see if my alternator is working? If it is not how do I replace it? I don't even know where it is on the bike or if there is anything else to check besides the fuses which I didn't find any blown ones. :mad::eek:

Also if someone maybe has a pdf file from the manual that explains how to do this that would be great!
 
#2 ·
Alt inspection: disconnect battery; disconnect plug and booted ground; remove cover; remove alt brushes, inspect for 4mm minimum brush length; if needed, clean slip rings with solvent and touch-up with fine sandpaper if not smooth; replace rubber rings if damaged. If Triumph doesn't sale brushes/ voltage reg/ rectifier, almost any automotive alternator shop could match yours (tell them ahead of time you don't want your alternator body painted, as some will do as a "courtesy" - painted metal runs hotter).

Leak test: turn off ignition; disconnect battery ground; set multimeter to highest Amp range; connect multimeter ground lead to battery ground, positive lead to disconnected ground cable; Clicking down on meter Amp range, a current flow of no more than 0.1Ma should be observed. If more, you have a short. Disconnecting> reconnecting electrical components, one at a time, while observing anticipated Amp drop, will help isolate short.

Output test: warm engine to operating temp; set meter to 12V DC range; connect corresponding positive> negative leads to battery; at idle, voltage should be close to 14V; rev to 5000RPM (in neutral, right), Voltage should read around 15V. If outside this, suspect regulator, rectifier or alt windings...

Use dielectric grease (Vaseline) on reassembly to thwart corrosion.

Hopefully, it's something simple (corroded, broke, loose connectors, etc.) on such a new bike (unless left in weather for extended period without a walk).

Big name auto part stores around here provide free charge system test. Just observe that tester connected properly without damage to bike! Hope this helps!
 
#3 · (Edited)
RE

Hey thanks for the speedy reply. Question I had was before I go taking my cover off of my engine is there a way to check if the problem is in the stator / rotor or the rectifier? How do I check if there is current coming into the rectifier or if the rectifier itself is just bad?

I traced out the wiring and there are three yellow wires in one connector which is where the power is coming in from the alternator, then another connector with two black that goes to ground, then two red that go into the fusebox. What I am trying to do is see if there is current coming in on the yellow wire when the alternator rotates or not. How do I check that with a multi-meter?
 
#5 ·
Your three wires from the alternator supply the "raw" AC voltage to your reg/rectifier. You should be able to disconnect them from the reg/rectifier and measure the AC voltage across any pair - should be around 18 volts or better at idle and increase with speed to as much as 50-70 volts ac. Exact voltage is not too important - it just HAS to be equal between any two of the wires. If this is the situation, your alternator (stator, actually) is probably just fine.
Assuming that to be ok, check that connections are good - no melting, discoloration or burning - and then you'll probably find that the reg/rectifier is bad.

You should also check the main fusebox to insure all fuses are good.

13, your instructions are pretty much dead on for the older speedy, but the newer ones have reverted from a proper automotive alternator to a traditional crappy total loss alternator - no brushes, no field windings - just a big rotating magnet. And I'd tend to think that 15 volts is probably too high for any vintage - I know at least a couple of 1050 speedies have measured 14-14.5 volts under all conditions, from idle to max.
 
#7 ·
...newer ones have reverted from a proper automotive alternator to a traditional crappy total loss alternator - no brushes, no field windings - just a big rotating magnet...
Thanks for the update Mr. V!!!

...[a] voltmeter to each yellow wire two at a time and got 0 volts ...

if you connect one wire on the meter to each yellow wire one at a time and the other side to ground and check for continuity there should be none, if there is the alternator is bad, is this true...

[c] is there a way to test if my rectifier has gone south or not? I asked a dealer and they told me there is no way to test it...

[d] does anyone know where I might be able to get a rectifier and alternator at a reasonable price besides the dealer...

[e] dealer told me most likely need new battery which is $100-150 because batteries only last 2-3 years anyway...

[f] assuming that it is the rectifier that cost $300-350. Then they charge a diagnostic fee of $95 which they will credit toward the repair so minimum they will charge me for 1-2 hours labor which is $95/hour. They also said if it is the alternator that is bad, that is over $400 (I hear a cash register in the background). I really appreciate the help so far from the community and I am hoping the information keeps coming.


Had similar problem to yours with my old beemer - turned out THE STARTER MOTOR had to be cleaned, which I did, and eliminated all these electrical anomalies.

a. 0 Volts doesn't sound good. On such a new bike, I'd double check wiring, fuses and all that...

b. That'd be a alternator winding continuity test, don't have diagram for '06 to verify wire colors...

c. The Rectifier basically converts AC to DC... it may be the rectifier is built into alternator and not easily tested (but not sure on your '06). I've gotten good results with cleaning alternators with (plastic safe, non-conductive) electronic spray.

Rectifier test: You're basically testing that the diodes are allowing current "one way" as spec'd. Place one lead of meter (or test light) to positive lead on rectifier. Touch the other lead one at a time to each of the terminals of rectifier. At this point you'll either have continuity or not (but it should be the same with all the AC terminals). Swap test leads (still working with the positive terminal of the rectifier) and repeat the test. This test should have the opposite result.

d. Shop around online (recommend new, not use electronic parts - don't buy someone else's headache)...

e. Make sure charging system operating properly (so you don't fry new battery). After which, new battery won't hurt (after going through a few NY Winters). I've had sealed and unsealed batteries last 5 years, but they usually don't. Get a Battery Tender (slow, low voltage charger with automatic off) if you don't have one...

f. Besides the thrill of a cash reward for figuring out how your bike works, there's the confidence of knowing you'll be able to fix it on the road if needed.
 
#6 · (Edited)
Problems getting worse and worse.

That's a great idea. Today I started the bike and put the voltmeter to each yellow wire two at a time and got 0 volts so i don't know if that means my alternator is bad. I had also read somewhere that if you connect one wire on the meter to each yellow wire one at a time and the other side to ground and check for continuity there should be none, if there is the alternator is bad, is this true?

Second question, is there a way to test if my rectifier has gone south or not? I asked a dealer and they told me there is no way to test it which made me wonder if they are just gonna start swapping parts at my expense.

Third is does anyone know where I might be able to get a rectifier and alternator at a reasonable price besides the dealer?

FYI I thought you guys might like to hear this. I called a dealer and told them what happened and they told me that I most likely need a new battery which is $100-150 because batteries only last 2-3 years anyway even though I have never had an issue with the battery once. Then assuming that it is the rectifier that cost $300-350. Then they charge a diagnostic fee of $95 which they will credit toward the repair so minimum they will charge me for 1-2 hours labor which is $95/hour. They also said if it is the alternator that is bad, that is over $400 (I hear a cash register in the background). I really appreciate the help so far from the community and I am hoping the information keeps coming.
 
#8 ·
Yeah, as 13 said, 0 volts doesn't sound good. Are you sure your meter is set for AC, not DC? I'd be a little surprised - just a little - to find all three sets of windings open. They can be checked with an ohmmeter - should read an ohm or two across each pair. Again, exact reading isn't important, as long as it's equal. And resistance to ground should be infinite.

For once, your dealer is right - rectifier/regulators have enough circuitry inside them that the easiest way to check them is by substitution. Good news is that most modern bikes use a very similar electrical system, so if you're a little adventurous you can swap out your rectifier/regulator for similar ones from Honda or Kawasaki or probably any number of Japanese machines. Some of the fancier ones use a field coil, but they'll have additional wires. Ones compatible with our speedy will have 5 wires - three of one color, usually yellow, and 2 for output. Connectors will be different so you'll have to do some splicing. But they appear ALL the time on eBay - picked one up last year for under $20, worked just fine. I wholeheartedly agree that it's a crap shoot buying used electronics, but with that sort of price differential, you could afford to buy a couple and still be way ahead.

There are a number of outfits supplying aftermarket stators (alternators) for our bike - there's a writeup over on "another" forum about replacing the stator and recommending a specific aftermarket unit - see

http://www.thespeedtriple.com/Forums/index.php?topic=7388.0

Again, a LOT cheaper than OEM, and replacing it is not a big deal.

And yes, a battery that's 2-3 years MAY well be at the end of its life, but I wouldn't replace it unless it was tested and found to be dying. Then again, as you may have noted from above, I'm a cheap SOB...
 
#9 ·
RE

Well I found a replacement alternator/stator for sale on this web site:
http://www.electrosport.com/street/street-model-products-listing-street_61700.php

They are both around $100. I sent an email to the company and was told the rectifier will work with my bike. I fired off another email about the alternator. To test the meter I put it in my wall socket and got 120V so I know for a fact it is working. I checked and the meter shows between 1.5 and 2.5 ohms resistance between all of the wires coming from the alternator but still got 0 Volts when the bike is running AC. I also checked for continuity with ground and found there is. I also tried taking off the alternator cover and oil started coming out, at that point I decided to put it back on and let the dealer look at it tomorrow. I have the service manual and nothing is mentioned in there about oil being in the alternator so now I am wondering if a seal let go and let oil into the alternator or if it is supposed to be in there for lubrication. Anybody have any suggestions on that?

See this section of the manual:
http://www.triumphrat.net/attachment.php?attachmentid=6800&stc=1&d=1213672063
 

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#11 · (Edited)
Finally an answer

Well as I suspected I brought my bike to the dealer and they found the alternator to be bad. Luckily the part is being covered under warranty. If anyone lives out in Long Island New York I highly recommend bringing your bike to Ramp Triumph in Port Jefferson. The service Managers name is Mike and he is a really nice guy, real professional and very helpful. Hopefully in another week or so I will be back on the road which is a big relief for me. Thanks everyone who replied to my thread for your help in solving my problem and it was also a good education because now I know much more then I did before how my bike works.
 
#13 ·
My 02 Sprint ST has let me down again, stranding me in Bayswater. At least it died 300m from a battery shop... With a new and charged battery was showing 12.3v at idle with the headlights on. Checking the voltage across the yellow leads shows at idle 12/12/7 at 5000 rpm 25/25/10. Pulling it out it looks a bit crispy.

Price here for a new one AUD825!!! And none in the country, next shipment expected late August!!! My friends at Eurobrit say they would charge AUD385, but they don't have any either and I can't find any non-genuine suppliers here. Local Auto electrician is charging about 300 for a re-wind - no bike for about two weeks either - fricken brilliant
 
#15 ·
Alright, I have the same problem. I took the cover off (little oil) and one of the magnet was pretty (black see pic). I thought I had it! checked the output on AC: 20 to a 100V varying revs. The voltage barely flicker up when I put the meter on a good battery while engine is compare to non running.When running I loose a 0.1-0.3V when I put high beam, signal, brake.

Is it safe to assume it is the rectifier? Bike is a garage 05 with 6000 miles.
 

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#16 ·
Just retested with with my meter in each of the three output at a time and ground and one shows zero. Think I have to replace stator then...The black (burnt) magnet was the cause. after I change it I'll see if I needed the rectifier.
 
#19 ·
Installed it and fired the bike. Sure enough 14V and change at the battery at 5000 rpm. I am good to go. (after I reseal the case and solder the connectors). All in all I got away with it cheaply. Don't let the dealer rip you off five Bills for this.
 
#20 ·
Lower voltage at higher RPMs???

My '06 S3 (12/05 mfg date) has been having problems starting recently. Maybe it's time for a battery swap, but want to make sure it's not the charging system that's the culprit.

This post has been really helpful, but I noticed something odd. With a DMM across battery leads during idle, I get ~14.4V. OK, that seems good. However as RPMs increase, say to 4k, it drops to 13.3V. I can see my headlights get noticeably dimmer also.

Anyone know what might this be an indicator of?

Thanks
 
#21 ·
Alternator Cover Removal - What's the Trick?

Hi, I was reading this thread because I had a little oil coming out of my alternator cover, so am relieved to see it will be a small quantity (especially since, as the manual and other posters have mentioned, you do not need to drain the oil to take the cover off).
My problem is that I have all the bolts out and it looks like it will take quite a bit of force to get the cover off. Is that true, or am I missing some secret hidden bolts? :) I see the manual says you have to remove against the pull of the magnets - do I need to break the gasket seal or something?
Thanks very much in advance!
Cheers,
Alien
'06 Speed3
 
#22 ·
Update - Alternator Cover Removal - Trick Resolved

Found an old post, quoted here:

This is the alternator cover. It has locating pins as well as the fasteners to hold it in place. The alignment is critical due to the fact the alternator must spin true in the center. The magnetic field of the permanent magnet will also provide some resistance to being removed. It must be removed straight out. There are 2 "tabs" on top and 2 "tabs" on the bottom of the cover. You can use these to try and get a grip on it or tap gently on. Tap the cover with a hard rubber or wooden mallet to free it up. This is one operation where a little care gets it done and a lot of muscle just causes bigger problems.

[ This message was edited by: Jimi_X on 2006-07-19 08:14 ]
and it is dead on. Thanks Jimi X! My biggest issue was breaking the gasket's hold. Once I got past that it was a piece of p*ss. Ideally you need a rubber coated or wooden hook that you can grab the tabs with and pull to break the gasket seal methinks. Since I am replacing my cover anyway, I did not care about scratching it to remove it so I just used a metal hook, combined with judicious use of a rubber mallet.

Cheers,
Alien
 
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