I have an 81 XS400. I want to bypass the safety relay, and eventually do a complete rewire with out the safety relays. I cut the red/white wires that go into the safety relay plug, and twisted them together just for testing. My thought process was when you turn the key power goes to coils, and to the red/white wire going to the solenoid. Which now it does. But engine switch on, i get power but nothing happens when I pushed the button. Hmm, i thought that was odd. For the heck of it, i flipped the kill switch, pushed the button, and the engine turned over, and I wasn't getting power to the solenoid. So clearly I'm wrong, and something is reversed. I followed the wiring diagram and I can't see where the issue would be. Obviously with kill switch off, i don't get spark when i hit the start button. But I get spark with kill switch on when I try kick starting it. For reference, I've only been able to get kick start to work. I got this bike as is. It came with a few wiring harnesses, and I took the worst of them apart to study how all of the wires connect using the wiring diagram as a guide. So not sure how i got these results.
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Rewire/relay bypass question.
- Thread starter Joemsanc
- Start date
One relay is for you headlight and the other is for your e-start. The headlight is to keep from power going to the headlight until power from the charging system kicks in. A good thing to have working. The other is hooked to the clutch safety switch and or neutral switch not letting the bikes e-start work until one of those are done. There are threads on these subjects in the forum.
Thanks for your reply. I totally understand that part. I'm just trying to simplify the wiring for this bike, as it is being turned into a cafe racer. What I'm trying to figure out is why when I cut the red/white wires going to the relay, splice them together essentially completing the circuit according to the wiring diagram. That the start button only works when engine switch is off. I'm suspecting my kill switch, but kick start works just fine with engine switch on. I know with cafe racers they usually just stick with kick start, but electric start isn't such a bad thing either once in a while. Also note the PO destroyed the wiring on this bike. I've thought about just rewiring the entire thing, which I'm not overly opposed to doing. Side note since you mentioned it, I installed an LED headlight, since the power consumption is lower, is the headlight relay important at this point. I was at least able to bypass that and get headlight working again.
Ok let me just simply the question. With key on, and engine set to on, i get power to the coils which I know is correct. Should I only have power to the red/white wire going to solenoid, and not the blue/white? If I understand this correctly, pushing the start button completes a ground to the frame causing the circuit to complete and firing the starter. The more i think/play with the wiring, the more I think there is something up with the kill switch. It has this random black wire coming out there is no where listed on the wiring diagram. I thought it was a ground since it was black and had a ring terminal. Only to find out its hot. If i have the kill switch off, then there should be no power flowing anywhere. The last time i had the switch apart i saw some corrosion, but no broken wires. I think i may to take it apart again to see what the heck is going on.
Could be a bad connection with the switch. But if your harness has been modified that could be the issue. I would follow what the wiring diagram says. That would be the easiest way but if your looking to remove stuff it will be more work. I can't say for sure what every wire actually does, I just know only where and what should be there.
Ok well hopefully someone who has done some custom wiring can chime in. Looking at the wiring diagram it should have power to at least red/white, and I assume when I hit the start button power would flow through blue/white. All I had were modified wiring harnesses which is why I will prob just rewire it. I’ve been chasing wires with my test light and multimeter.
The starter button grounds to the handle bars to the left side to the bars control switch. You need to have each side make good contact with the bars. If they are painted you need to scrape them to clean so contact is made.
