Hi, I have a Honda Sky SGX 50 electrical query I hope someone can help with. Firstly, I would really love to get my hands on a wiring diagram if anybody has one available? Secondly I would really appreciate some advice on a problem I have. I am having trouble with my sgx 50 blowing the headlight and taillight when the engine is revved. Background is that I bought the bike as a non runner a few weeks ago. Following various investigation I replaced the crank seals and now she starts and runs great. Whilst I had all the bodywork off I also painted the frame as it was starting to rust quite badly in places. Last night I put all the bodywork back on and did a quick check to make sure everything was connected back up properly and working. All OK except when I revved the engine the headlight blew, strange I thought but maybe just an old bulb. Switched to high beam which came on fine, revved the engine and that blew as well. Removed the bulb & confirmed it had blown then did a quick check a multimeter at the headlight bulb socket. DC voltage at the bulb holder goes from approx 6V at tick over to 50V at high revs. Was getting late so didn't have time to do any more investigation. Strongly suspect the regulator but before I purchase I want to rule out anything else as the 5 pin regulator costs over 60 pounds and it seems a strong co-incidence that was all fine before I pulled things apart to change the crank seals. By the way I am assuming that the lighting system is supplied from the regulator - this is where a wiring diagram would be especially useful. Given I had to remove the Rotor & Stator to replace the crank seals I intend to double check I haven't done anything silly when re-assembling. Also going to check the voltage at the battery with the engine running to see what the regulator is supplying to that part of the electrics (I think that the regulator probably has two outputs - one for the battery supplied electrics and one direct for the lights). One thought I've had is that when I first got the bike running the tail light was not connected up - could this cause any problems, could this have damaged the regulator due to there not being the correct load from the lighting system? Would seem a bad design if it did as bulbs can blow in normal operation and wouldn't want a blown bulb to result in an overloaded regulator. The headlight seemed to work fine at that stage and did not blow. Could a bad earth somewhere be causing this if I have disturbed the wiring somewhere and not realised? Could the lighting circuit resistor be involved? Am not great with electrics and learning as I go along therefore any advise would be much appreciated & apologies for the long post!! Thank You
Do the lights come on when ignition is on but not running ,its probably a ac lighting circuit and i would check the bulbs are all correct ? As you said it does sound like regulator packed up . Check the battery is decent enough too
The lights only come on when the engine is running. Done some more investigation. The light circuit is definitely supplies by the regulator. The regulator is 5 pin. one input from the stator. One output to earth. One output to the cdi/coil. One output to the battery supplies circuit and one output which supplies the lights and auto choke I think. The battery output seems fine as measures approx 14.5 volts with engine running. The CDI/ coil output seems to match the supply from the stator. Engine running fine so assume this is normal. The output to the light circuit is however way high when the engine is revved. Am thinking of trying to re-wire the light circuit into the battery circuit. Sound like a plan? Or do you think that might overload that output from the regulator? I did try and check the voltage supply from the stator into the regulator but get some strange readings into many hundreds of AC , can actually go off the 750v scale. Either my multimeter is not reading AC volts properly or ??? What could cause such high readings from the rotor???
You said the voltage at the battery when running is 14.5, is that on idle or when revved? Should be about 12.5 at idle . Unregulated voltage will blow bulbs . Wat colour wires are on the regulator plug?
Hi, I realise that this is a very old thread (2012) but just wondered if the original poster is still active on here, and if they ever found a Honda Sky sgx50 wiring diagram ?.....I could really do with one.....
