I know many of you have seen - and adopted - the R/R upgrade that I first authored on TriumphRat.net - Charging System Diagnostics - Rectifier/Regulator Upgrade
Here is a tailored version of that specifically for the 675. Much of the content is derived from the original thread, so no apologies for any repetition, but at least redundancy is all removed.
First of all, an accurate diagnosis of the problem is required - this appears as a mystery to many, including professional shops! But it really is simple and a little explanation will surely allow almost anyone to make a positive diagnosis to allow the best investment of the dollars to repair. There are only three major components involved - the stator, the Rectifier/Regulator and the Battery, followed by the passive components, the wiring & connectors.
As far as the battery goes, follow the old adage - "you get what you pay for!" Invest the dollars in a quality replacement if/when that becomes necessary. Yuasa is consistently a stellar performer but there are others.
Protect your investment with a good battery maintainer - I have both Battery Tender & Optimate products - the new Optimate 4 impresses me, I have a couple of those. Hook up the Waterproof SAE pigtail permanently to your bike's battery, so you can simply plug it in when you return (any time you plan to have non-operational period of more than a couple of days)
A basic troubleshooting process to determine whether you have a charging system failure.
A good Multi-meter is a pre-requisite.
Record your battery voltage under the follow conditions
1) Ignition off, unloaded battery.
2) Ignition on, headlights on, not running
3) Bike started, running at idle
For condition 1, should be at least in the high 12.x range if fully charged.
In condition 2, your voltage should not drop much below 12.0 at worst. (It may continue to drop - hopefully slowly! - as your lights will be discharging it. However this should be a slow decline)
If it does drop immediately into the 11's, your battery is insufficiently charged - if it was just charged from a battery charger however, then it indicates your battery no longer has sufficient capacity to retain charge/supply current to load and should be replaced.
Condition 3 is what we are most interested in with respect to charging capability.
Voltage should be at least in the 13's at all engine rpm. You may detect it will fall off slightly as you raise engine rpm. This is not atypical performance. A simple mod that can enhance your charging voltage to the battery can be achieved by this modification outlined in this thread
. That should give you performance in the 14V+ range.
What if you have less than 13V?
First thing to check is the fuse - this may have a different number depending on which model you have, so I will refrain from identifying a specific one. In the case of the 675 this is unlikely to apply - you will have no power to the bike at all if the main fuse (in the starter solenoid) is blown.
Next, examine the wires and connectors between the stator output and the R/R input (three wire harness and connectors) - are these charred/melted due to excessive heating?
That can be an early indication that you may have a shorted diode or SCR in the R/R, however these connectors themselves can be the source of the problem - poor fitting terminals create high resistance joints, heat & the problem is exacerbated - often these will arc and burn the wiring. Definitely need to be replaced if you see that, however also important to check for issues with the R/R also.
This stator connector plug below was from an otherwise perfect working charging system - there was NO
failure of the stator or R/R!
The connector I recommend is the Packard Delphi MetriPack 280 three conductor connector - much better quality, sealed waterproof connector - has much better engagement of the mating terminals
The R/R used in the Triumph is of the older SCR (Silicon Controlled Rectifier) design and has very poor reliability due to the self-generating heat from these devices. The regulator is a shunt device on the rectifier section and if one of those components goes bad, then it will pull maximum current from the stator. This may not be immediately apparent as you will possibly still see in excess of 12V at idle (possible higher at other rpm) but it will be obvious from the heat and associated burning smell!
This is an unfortunate situation - there is strong possibility that the stator will also be killed by this type of primary failure, if not detected early and continued to run in this condition.
Here are some simple checks you can do on the R/R module:
Perform a 'cold' resistance check for shorted diode or SCR in the rectifier section, which is going to be the predominant failure in these devices. It is VERY easy to diagnose a problem.
Unplug both input & output plugs from R/R;
With your meter set to read resistance (use a diode test if the your multi-meter has one), test from each pin of the three pin plug, to both the black/red (positive) & black/white (negative) wired pins of the 4-pin plug; NONE
of these should read short circuit (zero resistance); depending which way you bias the test leads, you will get some reading (from the forward bias of the component) but it must absolutely not be a short. If you see a short on any of these readings the R/R is defective and must be replaced.
Next, do a resistance check on the stator (check at the cable connector going back towards the stator itself).
Measure between the three respective combinations of the three pins:
This time each of these should measure almost short circuit (very low resistance in order or about 1 ohm)
Also check from any one pin to the engine ground terminal - this should not
read any indication - maximum resistance or open-circuit.
If you read 'short' in that last test, then your stator is definitely bad.
Not being short to engine casing is not necessarily an affirmative indication that all is well, compared to the contrary - a burned stator will invariably always have this short to engine, so is a very good initial simple check without having to open anything up.
If you did not measure a short between any of the pins and engine ground, next perform a voltage output test of the stator where you will check the AC voltage output from the stator with engine running:
Leave stator disconnected from the R/R and start the engines.
With meter set to read AC Volts check
All three should be the same value - any significant difference of one reading will indicate a bad phase and the stator is probably defective.
At idle this should be ~ 25V and rise to ~ 70V at 5K rpm. I almost hesitate to use absolute numbers here as this can be different between models and test equipment.
What you are looking for is same between phases and like increase on each phase as rpm increases.
If any of the above tests raises suspicion, pull the cover & inspect the stator. It is simple to do and can set your mind at ease by seeing what it looks like. Hopefully NOT with 1/3 of it a black charred mess!
If you have to replace the stator and R/R, especially because of a shorted R/R and excess current drain, be especially careful to ensure that your wiring has not been compromised. If the wiring has been fried, then you will continue to have issues and potential failure of those expensive components which have just been replaced! Replace any cable &/or connector plug that is not in optimum condition.
Upgrade Replacement for OEM R/R.
As mentioned earlier, the OEM R/R is a now somewhat dated SCR device - motorcycles from other vendors are now utilizing much more modern MOSFET devices.
You can consider this as an excellent quite cost-effective preventive upgrade measure with a better component, not necessarily limited to replacement on failure.
Either way, process is the same for failure or upgrade.
What makes these new devices better is that it is a MOSFET controlled device rather than the crude SCR type on the Triumph. It has MUCH better voltage regulation and runs cooler too due to much more efficient control.
The SCR shunt type consumes more energy in the Regulator itself than the bike is using and dumps a ton of current into the heatsink (feel yours & just see how hot those things run!!!! - don't touch it - you'll burn yourself - seriously!) The problem is exacerbated because their efficiency goes even lower when they get HOT so it's a vicious circle. Heat is the number 1 killer of these devices.
Incidentally its a misconception that these thing work harder with increased load i.e. higher-wattage lights, heated vests etc - actually, the higher the load on the output, the less work the regulator does in dumping that excess energy and will actually run cooler!!
The unit I think is best suited to the 675 is the Shindengen FH008 model that is currently utilized on late model Honda CBR 600's and 1000's.
The advantage and suitability come down to availability at a reasonable cost (typically $40 or less on EBay) and compact physical envelope for installation and easy retrofit into the 675.
Here is one such model (the last two letters suffix may change dependent on year/model bike and connectors)
Which one do I get??
Some models (depending on the last two letter suffix) have 4 output wires (2 +; 2 -) *- others only two (+ & -)
But both have the same excellent control system - The two wire units are a little easier to install.
The two-wire output models are the 06-07 CBR1000 and the 07+ CBR600.
Earlier or later 1000 models are not FH008 and 05-06 600 are 4 wire output (pre-05 not FH008)
To wire this up on your 675, I recommend the same MetriPack connectors shown above. You can also get a 2-terminal connector from the same EBay Vendor.
Remove the existing plugs from your 'newly acquired' FH008 and replace with the MetriPacks
If you have the 4-wire unit, simply strip & twist the two positives and two negatives respectively together before inserting in the single terminal for crimping or soldering
Of course you will replace the existing stator connector in your main harness with the corresponding mating half of the 3-terminal MetriPack
Wire them up per this diagram:
Note that you will be connecting the output of the new device directly to the battery terminals via a fuse.
Use a quality fuse-holder and 30A fuse for the output connector. It is critical that in these high-current circuits that quality crimped or soldered joints are used. If you do not have a crimp tool for the MetriPack terminals, then solder them.
I would strongly recommend against
using an ATM (mini) fuse holder even though these are rated for 30A.
Use an ATO/ATC fuse holder at minimum. Again, ideally the MetriPack fuseholders would be my recommended choice.
You can get these at Eastern Beaver
(no one-stop shop unfortunately - EB has the fuse-holders and two-terminal MerticPacks, but does not carry the three-terminal connectors)
You can be less concerned about the mounting location for this device - Triumph has moved around the location of the SCR unit to try to get more heat out of it, but haven't cured the fundamental problem, which is inherent in the SCR device. Those devices need to get good cooling (airflow) in order to avoid self-destruction and even then are still a ticking 'bomb'. Not to say that the MOSFET is impervious to heat, but the degree of self generated heat is significant and is much more tolerable of mounting location.
Here is an excellent install
with some great pictures.
I'll 'steal' one if I may for reference.
(picture courtesy of 07d675cm2