Source
r/motorcycles•
camelCaseCoder

Lighting and electrical question on vintage Yamaha

I'm working on restoring a 1982 Yamaha XJ650J Maxim. As of right now, when I turn it on or start it, the center taillight comes on, but the headlight (low and high beams) does not. When I turn on the turn signals, I either get no reaction or 3 of the 4 lights come on. As in both front turn signals and 1 rear. Is this likely to be a switch issue? Relay? Diode pack? What are the common electrical issues with these things? Any input would be appreciated.

Posted May 30, 2022, 4:49 PM UTC

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anotherreddituser73•

It's a 40 year old bike. It could be any and all of these things. I'd start simple with the bulbs and bulb sockets and plugs (look for corrosion), fuses, wiring (trace it back and check any connections/splices), etc...

2
camelCaseCoderOP•

I've got all of 0.147 volts going to the headlight bulb. Checked at a couple places up the harness and same voltage. I'll see what else I find. Fusebox is new, I already redid every splice in the harness carefully and thoroughly.

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bikergeekx2017 V-Strom 650•

If you don't have one, get a factory service manual. It will have the schematic that will show you how everything hooks up.

It's quite possible that the turn signal switch is causing the strange reaction. You could try spraying some contact cleaner in there and see what happens.

1
80-eh-emn•

I have an 82 750, so not exactly the same, but some of my experiences may translate. The flasher relay needs to be wired in correctly, the original is a two circuit relay with an auto cancel. If the original is worn out, you have the wrong replacement, or you have the line/load wires backwards, it can make all the lights come on. I got a new relay and it came with a wiring diagram. Think it was from super bright led dot com and was about $15.

The fuse box on mine was super flaky. I wired in a new blade style box and it fixed everything. Most auto parts stores will have 5 fuse auxiliary boxes for around $20.

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camelCaseCoderOP•

I think you might be right on the relay thing. Could you DM me or post the link if you have a minute?

1