what does blinking red light mean?

Hello and welcome to Apple Support Communities, bevstirman!

I understand you're seeing a blinking red light on you iPod shuffle and you want to know what it means. I'd be happy to provide more information about this.

Have a look at the following article: Check the status light and battery charge on your iPod shuffle

"iPod shuffle (2nd generation)

There are two ways to check your battery charge:

• If your device is already on, you can check the battery charge without stopping playback. Quickly turn your device off and back on, then check the color of the status lights. 
• Look at the status lights when you disconnect your iPod shuffle. 

Here's what the status lights mean:

• Green: 31% - 100% charge
• Orange: 10% - 30% charge
• Red: Less than 10% charge
• No light: No charge
• One green blink followed by two orange blinks for 10 seconds: Device should be restored because of an error"

Based on your description, it looks like your iPod needs to be restored due to an error.

I hope this answers your question.

Have a great day!