Signal Dynamics Heads-Up LED Voltage Monitor

I was handed a significant project at work a couple of weeks ago so updates have been scarce lately. My brain’s been fried to a crisp. However, I promised myself that I’d get at least one decent post in this week, and here it is. Not quite a review and not quite an install guide, this post covers the Signal Dynamics Heads-up LED Voltage Monitor I recently installed on the SV.

The Signal Dynamics Heads-up LED Voltage Monitor

Considering all the electrical accessories I run on my SV, I figured it would be prudent to have some sort of voltage monitor on the bike. I wanted something cheap and simple, and Tedder tipped me off to this particular voltage meter. It’s cheap (only $27 plus shipping), and simple (a single LED light to indicate the current voltage condition). I ordered mine directly from Signal Dynamics.

Inside the package is the voltage monitor itself, which consists of a small electrical controller box (i.e. the brains of the system) with an attached LED, a small panel-mount holder clip for the LED, a sticker showing how the different colors of the LED correspond to different voltage ranges, and some double-sided mounting tape.

The length of the wire between the LED and the controller box is about 16 inches, so if you intend to have the LED easily visible at all times, you’ll need to find a place to mount the controller box somewhere near the cockpit of the bike. Such things can be slightly tricky on the SV650, but I found a good spot on the back side of the gauge cluster.

The controller box mounted under the gauge cluster. Note the red, black, and tri-color wires leading from the controller.

The controller box measures roughly 2.25 in L x 1.5 in W x 0.5 in H, which makes finding a mounting location that much easier.

Once the controller was mounted, I connected the red wire to a hot (powered) wire that ran back to my ignition switched fuseblock and the black wire to ground. I turned the ignition switch on and was gratified to see the voltage monitor successfully run through its self test of blinking the LED green, amber, then red. The only thing left was rigging up some kind of bracket for the LED.

Thankfully, I never throw anything away. This ugly thing was my first attempt at a bracket for a switch to control my heated grips. I ended up going a different direction, but kept the ghetto bracket for posterity.

Bracket punched and ready for drilling.

After drilling the hole for the LED.

Bracket cut down to a more appropriate size.

And now, dear readers, I must warn you not to do what I did next, lest you find yourself with one broke voltmeter.

In theory, the little plastic panel mount clip for the LED will fit into the hole you drilled, ready for you to insert the LED from the back side of the bracket until it snaps firmly into place by the clip.

I say “in theory” because I could not for the life of me get the LED to snap into the clip. I tried for over 20 minutes using my bare hands, pliers, a tiny screwdriver, and I still could not get that sucker to hold. Without a secure fitting, the LED would simply fall out of the bracket.

My frustration peaking, I decided to put the problem aside until later, because I could always use a rubber band to hold the LED in place as a temporary bodge until I found something more permanent. I turned on the ignition and watched the LED blink green, then amber, then… nothing. Aww hell. You guessed it, I broke the red lead on the LED sometime during my struggles.

I really didn’t want to have to order another voltage monitor, so my only option was to replace the LED myself. It took a couple of days, but I found a red-amber-green LED at a local electronics parts store. I had no idea if a direct swap would work, but I hoped for the best.

I trimmed the broken LED off and wired the new LED to the controller box using test leads. Turned the ignition on and peeked at the LED — it blinked green, amber, then red. I was back in business!

Since I had the LED off the wire, I took the time to heatshrink the entire length of tri-colored wire back to the controller box for some added protection and a cleaner look. I soldered the individual wires to the LED, heatshrank each connection, then heatshrank all three together for that last bit of overkill.

The new LED came with a different sort of mounting clip. Instead of an open clip, there was a plastic lens that snapped into the hole. You’ll see the difference in the next set of photos. The LED fit right into the new clip, and I dabbed a little silicone sealant around the base of the LED to keep the moisture out.

All that was left was mounting the bracket to the clutch perch using the existing bolt.

The bracket and LED in its final location under the clutch perch.

The voltage monitor showing green.

Red alert!

For reference, here’s how the LED indicates what’s what:

• flashing green: above 15.2v (over-voltage is bad)
• steady green: 12.9 – 15.1v
• steady amber: 12.7 – 12.8v
• steady red: 12.1 – 12.6v
• flashing red: below 12v

A voltage monitor is a worthy addition to any motorcycle, especially if you’re running aftermarket electrical accessories. The Signal Dynamics voltage monitor is a particularly good choice: it’s simple, relatively inexpensive, and tells you all you need to know at a glance.