1965 Corvette
or any other 12 Volt Vehicle

Adding a Low Voltage Warning (Idiot) Light


With dash removed to replace dash pads and Converting "Battery Gauge" to "Volt Meter"   I decided to add low voltage warning (Idiot) light.

The addition is fairly simple and straight forward  "If you already have the cluster out and on a workbench"

**NOTE  ** This can be added with stock 'Battery Gauge" and could probably be mounted in various places and not require removing cluster.

All that is needed is LED light and a voltage sensor. Both can be obtained from Ron Francis Wiring The LS-11 low voltage monitor will light the LED when voltage goes below 11 volts. All that is needed to monitor is a 12v switched wire.

I obtained a BLUE LED from a local electronics junk store for ~$1.50 and mounted in top center dash cluster mounting hole but could be mounted anywhere.


Did testing of light with 9v battery:

I was also installing a volt meter and cluster plugs so extra wiring on below diagram is not needed. Just the 12v switch wire to the LS-11, ground wire and wire to LED which also needs a ground wire. I also have a 2 amp fuse on the 12v switched wire avoid problems.

Click on image for larger view

12v switched can be pick up off the ignition switch (ACC)

I used the BROWN wire that went to Radio Capacitor which was not in use for both Volt Meter and LS-11 input. The LS-11 comes with double sided tape so I just taped to back of cluster.


Below is a video of testing Low Voltage Warning light (Idiot).

This was done as I was installing cluster back in Vette with a battery that was LOW (about 12 volts) as you can see on Volt Meter. First I turn on the headlights, you will see LIGHT indicator flashing and Volt Meter will drop to about 11 volts then I start to raise headlights which will drop voltage below 11 volts and will turn on the Low Warning Light. NOTE: It really isn't as bright as it appears, just a bright LED right in front of camera. Also note I'm holding camera in 1 hand and pulling knobs with other hand JJ

Click play button ==>