Topic: 1971 Honda CB500 - Charging Issue (At wits' end)

[calj737]

The chirping is the m-unit telling you it is detecting a low voltage from your battery. You need to have your battery load tested now. Due to prior issues, it is possible it won't hold the charge under load.

It appears you're producing ample voltage and amperage, but the lithium batteries are sensitive to over-discharge.

[zerodaydave]

Tried to post a video but basically I swapped out the battery for a known good one and it did the same thing. Battery tests at 13.25v at rest for a few hours. Good right? Figured out if I twist my handlebars at all on the bike the bike will lose power and then cut back in and chirp. I realized the ignition switch is the culprit. If I jiggle it I can reproduce the issue.

Can the munit chirping be the sign of a short as well?

Dave

[Bankerdanny]

Could be. If the switch is bad it could be causingflickering voltage, which the m-unit interprets as a bad battery

[zerodaydave]

Just took it for a test ride. All is good I found a loose connector to the ignition switch. That was barely connected and touching the fork. Causing all sorts of havoc. My buddy who wired it didn't leave enough slack in it.

All is good. Lights are still flickering when I rev it only in 2nd gear but at least it's still rideable.

[calj737]

What lights are flickering? At the dash/gauges? Those are supplied from the AUX port, so he needs to insure there's ample slack for lock-to-lock movement.

[calj737]

And the chirping due to a short is another sign that the fuse has been "tripped" but reset. I missed that earlier.

[zerodaydave]

The turn signals flicker. Mostly the front but sometimes the rear. Is that the Aux port?

[calj737]

The turn signals flicker. Mostly the front but sometimes the rear. Is that the Aux port?

No, it should be wired that the M-UNIT is powering those from their respective TURN L and TURN R circuits.

You never said, but I'm going to assume that you used "stock" or "stock-ish" style controls at the handlebars? If so, you likely still have a ground issue. Maybe. Do the lights flicker constantly, or only when they are illuminated? Is it just the indicators, or do other lights do this?

If its only the indicators, and only when active, then its down to a poor ground. The M-UNIT has a built in flasher relay. It also allows you to program the indicators with a % of illumination for using indicators as running lights. And, if that weren't enough things to consider, programming the M-UNIT for which handlebar controls you have also matters.

If you can snap a picture of the L and R handlebar control units, and the indicators (are they stock or aftermarket? Are they incandescent bulbs or LED?) that would help.

Actually, some complete pictures of your bike would be nice too! 

[zerodaydave]

They flicker even when they are not active. They are led aftermarket turn signals.

Here are some pics. I hope it helps. Thanks man.

[zerodaydave]

More pics. That last pic with my finger on the wire was yesterdays issue. Identified and should be resolved shortly. Just trying to figure out this flickering thing now.

[calj737]

I see 1 thing I do not like, theres a solid black wire into the CONFIG port (left side). WHY!? Remove that (unless this picture was simply during a setup). If you ride with that wire connected, and grounded, you can lose all programming.

I wonder, if you start the motor and while its idling, what lights (Left side and Right side) are solid, what are flashing?

[zerodaydave]

It goes to the kill switch and I'll remove it. Thanks for letting us know.

The kill switch isn't really working right now anyways.

The lights are flickering on the left side.

[calj737]

Your YLLW/RED wire should go from RH control to START input (left side). Then, run a wire from START output (RH) to solenoid (where the stock Y/R wire used to connect). Here's the trick, in your stock RH control, you need a ground wire for the START button to complete the signal to START input. At your solenoid, the Y/R now carries power from START output, so your stock "black" wire switches to a GROUND (use solid GREEN).

Or, you could run START output to BLACK at the solenoid, tie Y/R at the solenoid to GROUND. And still run Y/R from RH to START input. confused yet? 

[zerodaydave]

Yea. I have a basic understanding of wiring. Haha.

But I think I get what you are saying and I will show him this.

Also the issue you from yesterday is fixed! Stoked on that.

When we first starting chatting you told me that the Clymer manual was pretty useless. Is there one you recommend?

[calj737]

The Clymer is useless for using an MM-UNIT to wire by. Its useful for mechanical stuff.

[zerodaydave]

Quick update: Bike is running really well. I've been commuting on it for a week or so. I did my first canyon run on it as well so I'm super psyched. Glad to report no electrical issues and battery holding constant above 13v. I did just purchase the m-lock and some bar end lights to replace the led turn signals. I also received the stator I had rewound at Ricks. So I'm gong to pop that in as well to replace the one I got off of ebay.

Thanks again man!

[Mr Ed]

Sorry to hijack but does the CB 400F also use an electro magnet instead of a physical magnet?  Thanks.  Ed

[scottly]

Sorry to hijack but does the CB 400F also use an electro magnet instead of a physical magnet?  Thanks.  Ed

Yes

[Mr Ed]

Excellent!  Thanks

[zerodaydave]

Me again!

Back after riding around with no issues for about a month!

This time I took the carbs off cleaned them out and synced them up.

During the syncing process the antigravity 8 cell battery died during the idle process.

I put the battery on a tender and performed a full charge.

Here are the results:

- at terminal 12.89v
- at idle (1k) 12.61v (manual specs 12v)
- at 2000 12.85v (manual specs 12.4v)
- at 3000 12.91v (manual specs 13.2v)
- at 4000 12.91v (manual specs 14.4v)
- at 5000 12.91v (manual specs 14.5v)

I'm correct in assuming I have a problem again right? What could have changed I didn't touch any of the wiring!

The whole charging system is brand new with the exception of the battery which has been discharged a few times when I had my past charging issues.

[calj737]

AG batteries are not very tolerant of full discharge. You may have toasted it. Best to get it load tested.

[zerodaydave]

Honestly it's been discharged so many times I'm thinking that's what it is too. Question though. Wouldn't the voltage increase while I'm revving even though the battery was bad and couldn't hold it? You should still see the voltage go up to spec right?

[calj737]

Not necessarily. A damaged battery can no longer reach its potential due to the destruction of the charge plates internally. (Lay explanation, as thats all I'm good for). Typically, a bad battery won't recharge fully.

Little tip for you: when tinkering in the garage, or tuning, disconnect the output side wires from your m-unit except for START and AUX. Then you draw less current from the battery while testing.

[scottly]

Question though. Wouldn't the voltage increase while I'm revving even though the battery was bad and couldn't hold it? You should still see the voltage go up to spec right?

Yes, if the charging system is working properly, the voltage should go up, more slowly if it is recharging an undercharged "good" battery, and much quicker with a "bad" battery, or no battery at all.
BTW, your "tender" may not be fully charging your battery: after sitting, a fully charged LiFe battery should read over 14V with no load.

[zerodaydave]

I've ordered a new battery. Hopefully that's it. We will see. Fingers crossed. I didn't load test it because I couldn't find a place around me that could do it. I agree that the full charge is only coming out at 12.89 after 10 hours. In the past it was around 14 like you said.

Everything in the charging system is new like I said. And honestly with the help of Calj737 it was charging to spec up until I took off my carbs and let the battery die twice trying to sync them.