QUARANTINE
Diagnosing Motorcycle Electrical Problems
Back in Austin I had some electrical problems with the bike that I decided to put off because it was winter and I wasn’t really riding as much anyways. It started when I accidentally left the parking lights on (why is that even a feature?) at work, then culminated with the bike dying at stop sign on my way home. I thought the battery was toast from being drained so many times so I bought a new battery.
I shipped the bike here and it started right up. I figured I would take it out for a ride responsibly just to get out of the house and stretch mine and its legs. It started right up and rode like a dream for 20 miles of highway riding, then died after breakfast. Hmm.. I got it bump started but it wouldn’t turn on again at the gas station. I got it jump started with a nice fellow with jumper cables, but it died again at a stop light. Now this seems familiar.
I had to get it towed with my friend’s truck to his house where we put it on a slow charger for a few hours and I was able to ride it home.
What a frustrating day! The silver lining though is I have another quarantine project! My brother linked me this handy flowchart for diagnosing electrical problems for motorcycles and on a nice day my friend and I got out our tools and multimeter to figure things out.
Getting to the SV’s battery is very easy, you just remove the seat. I assume it’s like that for most if not all motorcycles. I am a pro at getting the seat off (requires two hex keys) from all the dying and jumping I had to do back in Austin. The regulator / rectifier is a bit more challenging and requires the removal of the rear fenders. I appreciate svrider.com for the often vague but sometimes helpful instructions because removing the rear fenders is not as simple as you might think.
Thankfully the entire flowchart can be done without unearthing the stator. Not sure if you got this far if you’re not into motorcycles, but basically the stator is the motorcycle equivalent of an alternator in a car. Actually alternators have stators inside of them, but functionally for the motorcycle it does the same thing. That is to say, it converts energy from the engine into electricity for electrical components on the bike such as lights, the starter, and the battery.
The regulator / rectifier is what takes electricity from the stator and converts it into a safe format so as not to blow up the battery, the starter and lights.
I won’t walk through the entire flowchart because you can just read it yourself but we determined at the end that the regulator / rectifier wasn’t passing electricity properly. This is actually pretty common for the first gen SV, and a lot of people recommend replacing this part as soon as possible. I’m not sure how mine survived for so long! I’ve had the bike probably five years now! Anyways I looked up viable replacements. The internet strongly recommends against replacing with an OEM R/R. You can use a variety, just be aware you may need to do some rewiring with R/Rs from bigger bikes.
This guy uses an R/R from a CBR600rr and a CBR1000. Him and his wife really love SVs and have had this issue with every one they’ve owned. This svrider recommends MOSFET R/R which is less prone to overheating and thus destroying itself. I followed the eBay link posted in that thread and bought that R/R so we’ll see how it goes when it arrives.
Stay tuned for part 2 when I replace the battery and R/R!