Bonneville America Forums Forums Technical Forums General Tech Flickering lights

This just started happening recently and I'm trying to get ideas of where to look first. I noticed this while coming back from the Dragon run we did a little over a week ago. All the lights on the bike (headlights, tach, speedo, light bar) will go a little dim then brighten up again like I've got a modulator on the headlights. It does it with the light bar on and off but doesn't do it all the time. A friend of mine at work who rides says it's probably a short that's developing. I haven't started digging into my bike yet to find it and wanted to get ideas of where I should look first and what I should do to find it besides looking for frayed wire or loose connectors. Headlight bucket? Fuse box?

If all the lights show the same symptom, then it must be something common between them all. I don't have a wiring diagram, but I would bet it's a common ground that perhaps is working it's way loose. I'd first check the ground connection from your battery to the bike, and make sure it's clean and tight. If that's good, then try to get access to a wiring diagram and see if there are any common wires between all the lights effected. Most likely it's just a loose connection, so even just disconnecting and re-connecting plugs and removable connections can sometimes cure the problem.

Cheers,
Brad

check all fuses , and clean the contacts.
could be the altinator or the regulator?

Step one: Get some dielectric grease. Then proceed as directed above. I find cookies make this sort of thing easier. Oatmeal raisin is best.

Hopefully something much simpler:
I had those symptoms and tracked it back to a loose negative battery cable. Tightened it up and not a problem since. At first, I thought the flickering was my imagination, but wife confirmed and I got my Sherlock Holmes hat out...an easy fix fortunately.

Glad you solved your problem Al.. for future reference there's a wiring diagram (for a Bonneville, but it's close enough) on my website.

Matt

First suspect is battery cables, check both ends of both cables.
Next, check the wiring to the rectifier/regulator, the finned thing mounted just below the oil cooler.
If everything is good so far, the battery or a rectifier may be going bad, but you need shop equipment to test this.
Not terribly likely but possible, the engine mounts might be a bit loose, disrupting the ground there.

Thanks everyone, I think it was a loose battery cable. I tightened down the bolts after cleaning the contacts and I also found that the main fuse wasn't seated firmly. I rode home last night and didn't get any flickering. The bike has been running beautifully otherwise. I was thinking that my battery might be getting ready to go out on me but she starts right up every time.

Gotta love it when it's the simple things...

This brings up an important flaw in assembly at least with my situation. I, too, had flickering lights which quickly turned into quick cut outs at speed...any speed.
After investigation I noticed that the 30amp fuse was loose..so much that it fell onto the garage floor when I removed the fuse box cover.
Well...the connectors had worked themselves loose to the point that they had fallen out the back of the fuse box...and they were not going to snap back in.
Evidentley they were installed this way from the factory...and someone had to have know about it.
My dealer stated that if I wanted to fixed it then the whole wiring harness needed to be replaced..under warranty.
I don't like anybody touching my bike so...
I cut the ends of the 30amp wires to the fuse box and splice/soldered in an 30amp in-line fuse.
Beware of the things you wouldn't normally beware of..its always the $1 part that puts you out of the race...

That's good to know Doug, thanks. I've had a look at the back of the fusebox before when doing some other mods and cleaning. I'll have to check it out. The main fuse went back in fine and I jiggled it around a little (tried to anyway) to see if I could replicate the problem but it was pretty tight.

Good deal, I love a no-cost fix!