I measured mine to be 10.5 volts. Is it supposed to be that much lower than the battery voltage?

 

At the ignition switch you should see source voltage. So if your battery is 12.6V, you should see really close to that at the switch. Check your battery's voltage. It may be sitting at 10.5V. If not then you have a resistance issue in the wiring. Either corrosion, partially cut or frayed wiring or wiring that is pinched somewhere.

 

turned out to be the latter. i think the previous owner wired the turbo timer in series with the ignition voltage rail and so there was a voltage divider