1. We checked the resistance on the black wire from the regulator and rectifier to the battery terminal and it read about 1 ohm. What should we expect? You had mentioned .5 volt. What exactly are we looking for in result?
2. The green wire form the regulator was fried, and when bypassed directly to the frame, the voltage dropped.
3. all resistance checked on the bike including the headlight harness was consistent at about 1 ohm.
4. Is it ok to simply directly ground the rectifier and regulator to the frame and bypass the harness?
5. Would replacing the harness solve the problem? ie, with a new one?
thus far we have checked the alternator etc and all function properly. We took the gel battery out and replaced with a standard battery.
My thanks in advance...
This..would fix my current high stress and depression for sure.
The voltage regulator is trying to keep the battery voltage at 13.8 to 14.5V if it is adjusted correctly.
To do his, it has to know what the actual battery voltage is. If the wiring connectors and switches drop/lose voltage, it will try to keep it's terminals in the 13.8 to 14.5V range by telling the alternator to keep pumping current into the battery. Too high losses will overcharge the battery, even if the major components are working perfectly.
Switch contacts can become resistive, which drops voltage. Connectors can become oxidized, resistive and drop voltage. The voltage drop becomes greater with larger current demands, such as when lighting is added to that black wire distribution branch. It's ohm's law E= I x R. Clean solid contacts are required for proper vreg operation to properly maintain the battery. That is its primary function.
For reference, a 1 ohm resistance with 5 amps drawn through it will eat/drop 5 volts of potential. The lower resistance you can achieve in a pathway, the less voltage loss you will encounter. This not only makes the parts work better, but less power is lost/wasted by the circuit in the form of heat, by drawing current through that resistance.
The reason for a harness ground is to limit the amount of current flowing through the frame. Electricity and moisture induce galvanic corrosion, which it not good for frame longevity. I will not use the frame for electrical paths if it can be avoided.
As you have found out, the components work using BOTH the power POS paths AND the power Neg paths. For them to function, both need to be in proper operating condition.
If you want the bike to be reliable, I urge you to correct the issue with your bike back to factory specs, rather the bypassing and band-aiding problems you have found. Fix what is broke and out of spec., and surprise, the bike will do what it was meant to do.
The wires in the harness are probably fine. It is the connectors that get oxidized. It is worth while to clean each one and then protect the mating connections with a dielectric grease. I prefer silicone as water won't wash it off, and it blocks further oxidation. It's a tedious job, but the results are worth it, imo. Worth a day, in return for working reliability.
Of course, wires with melted insulation, need replacement. If there are a lot, maybe a new harness is warranted. I generally use donor harness parts to restore burnt wires on a piece by piece basis. I haven't needed a wholesale harness replacement ever. I can imagine cases where it might be a better option, though. But, only half the connectors will be clean with simply a new harness replacement.
Accurate resistance measurement can be tricky, especially in the low values involved here. A wire from battery to vreg in good condition would have 0.05 ohms or less. That is hard to measure with commonly available meters. Which is why I usually use the Voltage loss as the observation metric. A Voltmeter displays the voltage potential between it's probes. So, a probe on the battery terminal and one on the VREG black connection, reports exactly the voltage lost between those points. Same would be true if you used the battery neg to green connection to the Vreg. Add those two measurements together and now you know what the Vreg is dealing with in error reports. Remember, if the lighting is on, it will exacerbate that reporting error (and make the headlight dim, too).
Cheers,
