2013 EC250 blowing voltage regulators

[rubber Jonny]

Hi all,

My 2013 ec250 has about 70 hours on it now and in this time its blown 2 voltage regulators one at 40 and now at 70 hours. The headlight bulb totally shatters when the regulator goes.

Does anyone have any ideas/on why this could be happening? Surely this is more than bad luck? Once maybe but not twice........

Cheers, RJ.

[Coop]

I would start by checking the output from the stator at both idle and while being revved.

[rubber Jonny]

done that, im getting between 13v and 16v depending on rpm.

[Neil E.]

That sounds about right. My measurements showed 15.4 VDC max at the battery. I would be concerned if it went over 16V.

I would suspect a bad connection somewhere or possibly the mounting/grounding of the case. On my 2011, the voltage reg/rect bolts to the aluminum subframe. This dissipates heat well, although I don't think these units warm up all that much. I know a 3 phase reg/rect will run much warmer (street bike or some dualsports).

Trace the green/yellow ground wire on the reg/rect and see if it has a good connection to frame ground. Note that some wires joints are hidden in the sheathing and are hard to get at.

Definitely trace the wires from the stator to the reg/rect. Remember that the reg/rect basically shunts excess voltage. If your yellow wire (AC lighting) did not connect well to the reg/rect the excess voltage would not be clipped and then the over-voltage would take out the lights.

This raises the question: How do you know it's really the reg/rect that fails? Maybe it's time to cut one of the old cases open to see if a diode is melted. Changing out the unit might have moved the wiring enough to re-establish a connection.

[Neil E.]

I'm not convinced it would take 30 hours for a bad connection to show up, but I've seen some strange things. I once had a section of wire that looked and felt perfectly good, but the copper inside was corroded through. Likely a defect in the copper.

[rubber Jonny]

When i got this bike it had done 30 hours, the regulator blew at 36, gas gas gave me a new one free of charge as the bike was 5 months old. Now its over the 6 month warranty so its not covered and has done 70 hours. I ordered a trail tech adjustable regulator (ac only no battery / starter etc) as people seem to consider these a upgrade, more reliable and the same price. I have had the flywheel off and its perfectly clean in there looks fine, no discoloring dirt etc.

Its arrived today so hopefully i will get time to fit it and see what happens.

[rubber Jonny]

And its fitted. Still spikes to 16v at the head light bulb holder when revved. Tried a bulb and popped it........

[Neil E.]

Stolen from the internet:
Continuous-preservation (float) charging: 13.4 V for gelled electrolyte; 13.5 V for AGM (absorbed glass mat) and 13.8 V for flooded cells
All voltages are at 20 ?C (68 ?F), and must be adjusted -0.022V/?C for temperature changes.
Float voltage recommendations vary, according to the manufacturer's recommendation.
Precise float voltage (?0.05 V) is critical to longevity; insufficient voltage (causes sulfation) which is almost as detrimental as excessive voltage (causing corrosion and electrolyte loss)
Typical (daily) charging: 14.2 V to 14.5 V (depending on manufacturer's recommendation)
Equalization charging (for flooded lead acids): 15 V for no more than 2 hours. Battery temperature must be monitored.
Gassing threshold: 14.4 V

We can say 13.5V for storage charging and approximately 14.4V for daily operation. So yes 16V is high. I only use LEDS lights on my bike, maybe the 15.4V maximum I've seen is being handled OK by my electronics.

If your voltage never goes over 16V, it sounds like your regulator is working. Your windings probably output 60V at maximum RPM. The 16V will definitely shorten bulb life, but I would expect the bulb to still last multiple hours.

It may be that a battery equipped bike holds the voltage level lower because of the presence of the battery. I suggest you try loading the system with more wattage to see if that pulls the voltage down. Try using a 100 watt headlight bulb.

No one else has posted about bulb blowing that I can remember. There must be something odd about your bike.

[Neil E.]

Googling "16V headlight bulb" brings up lots of choices, so manufacturers must expect bulbs to function at that voltage.

[Neil E.]

Originally Posted by rubber Jonny

I ordered a trail tech adjustable regulator (ac only no battery / starter etc)

As far as I know Trailtech only supplies a fullwave rectifier. Did they say to use it on a non-floating electrical system? It might only function as halfwave in this case (which would match what the stock unit does).