i have a 03 vmax, at idle i get 14v but at 2000rpm it drops to 6v or so. whats the deal?

Question

the man.says changed the starter coil and the stator coil on the same page? i know it's a typeo but which one is it?

Answer 1

If one of the windings (there's 3) on the stator is shorting, it'll charge around 11.25 volts, period. Don't waste several hundred bucks on one just yet. At idle, I find it hard to believe you're getting 14 volts, especially with automatic on headlights. 12-12.5 volts is more believable. You'd need to have two windings on the stator shorted out to get 6V and there's no way you'd EVER get 14V out of it in that condition.

First off, you need to pull your bike up to within 15-20 feet of a wall or building, preferabaly white and at night. With your headlight aimed at the wall, notice the level or brightness at an idle and then slowly speed the engine up. Somewhere, probably between 2,000-3,000 rpm, you should see the light suddenly brighten up and stay at that brightness at higher rpms. If the light does brighten up, the the alternator is working fine.

You didn't mention if the voltmeter used to measure the voltage was standard on the bike or a seperate meter (volt meter or multi meter). If on board, neither did you mention if it was analog (needle) or digital. If the headlight thing says things are ok and you have an on board meter, I'd look for a loose wire connection somewhere if analog. If digital, either a bad connection or bad meter.

While I'm not sure, I imagine your bike has an excited field alternator. It's possible the brushes or slip ring is worn and a poor connection is being made, but neither would that explain the unreasonabaly low 6V.

Answer 2

Worn brushes/sliprings will produce this symptom & damage. They have a wear limit mark-replace if not visible when whole brush exposed. A $10- fix, BTW. There is another possibility: check the faces of the windings. (Brg failure!) If there is ANY damage to the laminations, & they touch each other, they will have a short for their eddy currents, and will reduce Voltage at speed. Do NOT run windings without a load, they usually overvoltage and short out internally. (Look for signs of heat) Stators are 1 piece windings, starter coil has no exact meaning, tho' he might mean the central rotor, which excites the whole alternator into operation. They aren't cheap. Sounds like he's replaced both rotor and stator-big $$$$$$$!!!!

Answer 3

make sure battery is fully charged, and will pass a load test. Check stator insulation and ac voltage as per shop manual. If both ok, then replace regulator/rectifier.

Answer 4

STOP!! ……………….Replace your voltage regulator. Or at least have it test it to confirm I’m right; then replace it. Check this out, this is what I believe is happen to you. At idle things are cool,……………. Getting 14vdc………………………then when you increase you rpms the voltage drops…………………. See the problem I believe is your regulator; it can not regulate the extra current you bike is producing at the higher rpm thus shorting or just quit regulating at a certain rpm.