Headlight blowing woes on my rh50

[magnetb0y]

Help help!
Started getting blown headlight issue, replaced with 3 different headlight bulbs, (good better best quality) with same effect.
Replaced Regulator, same issue.
Checked Voltage, have 17v at socket and at battery.
Bought new resistors, resistor B is easy to find right behind headlight.
Resistor A, which most likely the issue, where the heck is it?
Its a 30w resistor so pretty sure it could be the issue.
Anyone replace one on a roughhouse/blackcat?
Anyone have any other ideas why I keep blowing headlights?

[johnk]

What exactly do you mean by "blown"? If the bulbs are breaking, there might be some moisture getting in and touching the bulbs, or you might be transferring oil from your fingers to the bulbs when installing them, which can cause hot spots and lead to breaking.

[magnetb0y]

Hi I understand, I meant filament breaking not glass.
I’m looking for the location of resistor A if you know.
Regardless of the solution I’m very curious where it is.

[tenders]

If you’re seeing 17V on the steering column, the problem is the regulator (aka rectifier), not a missing headlight resistor...and the problem is going to zap every other electrical thing on the scooter. Replace the regulator!

[Stanza]

If you’re seeing 17V on the steering column, the problem is the regulator (aka rectifier), not a missing headlight resistor...and the problem is going to zap every other electrical thing on the scooter. Replace the regulator!

"Replaced Regulator, same issue."

That resistor isn't for your headlight, it's part of the choke circuit to keep the heater in the autochoke from running wild and melting itself.

When you replaced the regulator, did you use a Genuine OEM part, or a universal?

[magnetb0y]

Universal but quality, I had also replaced prior with a cheapo china one but same, I just thought it would be silly that it would be the exclusive problem after two swaps... I did buy a PGO one that arrived today but logic would be that why would every aftermarket also produce 17v (thats at full rev) as well the battery can take it, Im going to switch to the PGO one tonight but for some reason I have a feeling not going to matter, thanks for the info on the resisstor, I was wondering what the heck it was for

[tenders]

I hear you that the problem persisting after replacing the regulator is bizarre. But I can think of no explanation for how excessive voltage can be caused by anything other than a defective regulator. 17V is the very definition of unregulated voltage, and there really isn’t much going on in this system: AC is spun out of the windings and is converted to DC by passing through diodes and then possibly held across a capacitor to help stabilize the rectified pulses. All that is inside the regulator. If the stator/rotor generating the pulses is defective, the voltage generated is going to be low, not high.

Some regulators are slightly user-adjustable, or “smart� and self-adjusting, to allow slightly higher voltage to charge a discharged battery more quickly, but we’re not going to see that on scooter regulators.

Can you test the old regulator on another scooter? If the battery’s operating voltage is 17V, what is its resting voltage across the terminals with the ignition off?

One super long shot: is your battery dead or in very bad shape? Is it possible that its connection to the cables are tenuous, corroded, or otherwise impaired? It is possible that if the rectifier cannot see the battery in the circuit it could dump high voltage into the circuit.

[magnetb0y]

Just an update, I installed the PGO regulator and a new HS1 bulb
and so far so good, holding 3 days. I guess it means that much,
or somehow through all the manipulation rekindled the circuit.
Will post if situation changes, but as of today it's PGO reg or bust
for a RH50 with issues.