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Discussion Starter · #1 ·
Hi everyone,

The bike gives me a low voltage light on the dashboard and eventually dies when I'm stuck in gridlock.

This has happened twice now, both times when I was low on gas, in mostly gridlocked traffic, and the fan was on for nearly 20 minutes in mostly stopped traffic.

I have a theory that at idle in traffic, with my aftermarket wannabe Daymaker installed, incandescent signals and brake lights on, and the fan going, my bike isn't making enough power.

I've tested the battery with a battery tester and it reads ok. I don't have any reason to believe my charging system has an issue.

I'm looking for any all information or advice that I should know that could help me out.

Is there a min. rpm the bike needs to be at to recharge the battery?
Anyone else have this problem?
Would changing my tail light and signals to LED lighten the load and avoid this?
What else could I do?
Anyone else have this when they switched to a daymaker light?

Thanks very much :)
 

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Hi everyone,

The bike gives me a low voltage light on the dashboard and eventually dies when I'm stuck in gridlock.

This has happened twice now, both times when I was low on gas, in mostly gridlocked traffic, and the fan was on for nearly 20 minutes in mostly stopped traffic.

I have a theory that at idle in traffic, with my aftermarket wannabe Daymaker installed, incandescent signals and brake lights on, and the fan going, my bike isn't making enough power.

I've tested the battery with a battery tester and it reads ok. I don't have any reason to believe my charging system has an issue.

I'm looking for any all information or advice that I should know that could help me out.

Is there a min. rpm the bike needs to be at to recharge the battery?
Anyone else have this problem?
Would changing my tail light and signals to LED lighten the load and avoid this?
What else could I do?
Anyone else have this when they switched to a daymaker light?

Thanks very much :)
The VRSC alternator is weak (22 A or 319 W) at idle (1200 ± 50 RPM). The alternator doesn't start charging the battery until 3000 RPM and doesn't reach full amperage (36 A or 522 W) until 3600 RPM.

The fans draw 5.86 A each (≈ 12 A total = 170 W). That’s nearly half your total output at idle.
The head light could be as much as 4 A = 60 W or more. That would leave < 90 W to run the fuel pump, ignition, and fuel injectors (as well as the electronic circuits).

The fuel pump draws 4.5 A = 65-¼ W
The fuel injectors draw 3 A = 43-½ W and
The ignition coils draw 4 A = 58 W
Those three = 11.5 A = 167 W.

Any deficiency not supplied by the alternator is carried by the battery. If your battery is weak that could explain your engine shut down issue.
 

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Discussion Starter · #4 ·
Thanks everyone. I'm going to take this knowledge and sit on it for a bit. I'm hoping that with cooler temperatures, this will be less of an issue, and that will buy me some time to switch my incadescents over to LEDs to hopefully lighten up the load a bit.

This only seems to happen on hot days when the bike is near empty.

Any other suggestions for next steps?
 

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Even an aftermarket LED should consume less power than the stock headlight.
 

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Discussion Starter · #6 ·
This bike is being really wonky.

Her dashboard backlight started flickering, then it went out completely. I get a check engine light. Eventually it went away. The dashboard started flickering again. Then it came on and behaved perfectly normal for the rest of the ride.

When I get in from my rides battery is always around 13.56 volts though so I believe it's charging?
 

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This bike is being really wonky.

Her dashboard backlight started flickering, then it went out completely. I get a check engine light. Eventually it went away. The dashboard started flickering again. Then it came on and behaved perfectly normal for the rest of the ride.

When I get in from my rides battery is always around 13.56 volts though so I believe it's charging?
Check all the ground connections and clean the plug that goes into the speedo cluster.
 

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They are also very sensitive to loose ground cables.

There are (I believe) 3 ground cables. Seriously check that they're all tight on both ends.

And spend the $$$ on a shop manual. Invaluable for finding all the parts and how to get to them.
 

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Discussion Starter · #11 ·
I ended up putting an Aprilia Shiver 750 on the road, I'm riding that now. Just towed the VRSCD to the dealership I used to work at because it's been years since she's been in front of a licensed mechanic and I feel like she could use a thorough once over.

As mentioned, I put the battery on a battery tester and she came up OK. I'll let you know what the mechanic says.
 
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