Runs with no lights

Most of the time this symptom indicates a low battery that needs to be charged or replaced. If you don't have a voltage meter handy, a quick and easy test to verify this is to plug your charger into the wall and connect the Vexilar at the same time (you will not hurt anything by doing so). If your Vexilar comes back to life when the charger is connected this confirms your battery needs to be charged or replaced.
To properly check your battery with a voltage meter:

1. Fully charge the battery
2. Disconnect the charger
3. Put a load on the battery by running the Vexilar for at least 10 minutes
4. Connect your voltage meter to the battery

No battery is the same so it's hard to put an exact number on what determines a good verses a bad battery. A voltage reading around 12.5V (give or take a few tenths of a volt) would be considered a good battery. A battery reading lower than this does not mean it's unusable, it just may not last as many hours as battery at 100% capacity.

Colors flashing "wildly" around the dial

Most of the time this symptom indicates a low battery that needs to be charged or replaced. If you don't have a voltage meter handy, a quick and easy test to verify this is to plug your charger into the wall and connect the Vexilar at the same time (you will not hurt anything by doing so). If your Vexilar comes back to life when the charger is connected this confirms your battery needs to be charged or replaced.
To properly check your battery with a voltage meter:

1. Fully charge the battery
2. Disconnect the charger
3. Put a load on the battery by running the Vexilar for at least 10 minutes
4. Connect your voltage meter to the battery

No battery is the same so it's hard to put an exact number on what determines a good verses a bad battery. A voltage reading around 12.5V (give or take a few tenths of a volt) would be considered a good battery. A battery reading lower than this does not mean it's unusable, it just may not last as many hours as battery at 100% capacit

Lights are dim

Most of the time this symptom indicates a low battery that needs to be charged or replaced. If you don't have a voltage meter handy, a quick and easy test to verify this is to plug your charger into the wall and connect the Vexilar at the same time (you will not hurt anything by doing so). If your Vexilar comes back to life when the charger is connected this confirms your battery needs to be charged or replaced.
To properly check your battery with a voltage meter:

1. Fully charge the battery
2. Disconnect the charger
3. Put a load on the battery by running the Vexilar for at least 10 minutes
4. Connect your voltage meter to the battery

No battery is the same so it's hard to put an exact number on what determines a good verses a bad battery. A voltage reading around 12.5V (give or take a few tenths of a volt) would be considered a good battery. A battery reading lower than this does not mean it's unusable, it just may not last as many hours as battery at 100% capacity.
Lights on older FL-8's or FL-8SLT's were dimmer compared to newer units. If you have performed the tests stated above with no change in light brightness it's probably just how they are.
It's also possible there is an accumulation of brush dust on the slip rings and lens. You can send the unit into Vexilar for a general cleaning or you can do it yourself. Look under "Manuals/Instructions" in "Learning Center" for instructions on slip ring cleaning. Typical cost of a general cleaning is $20.00 labor plus $10.00 shipping.

Lights have black lines "chattering" inside them

This is probably due to an accumulation of brush dust on the slip rings. You can send the unit into Vexilar for a general cleaning or you can try and do it yourself. Look under "Manuals/Instructions" in "Learning Center" for instructions on slip ring cleaning. Typical cost of a general cleaning is $20.00 labor plus $10.00 shipping.        

Can't see the lights in the sunlight

If you have an older FL-8 or FL-8SLT the lights on those units were dim compared the newer units. That was just the technology of the time they were made. These units do get washed out in the sunlight easier than the new ones. Unfortunately there isn't any great solution to this problem other than finding a way to block the sunlight from the flasher as best you can.