Non-working Aux fuel pump in 912iS

Hi All,
I have been flying my RV-12iS for 66 hours and this problem just popped up. This is on a Rotax 912is Sport engine with 2 electric fuel pumps (and no mechanical fuel pump).

The auxiliary fuel pump doesn't turn on and it's switch doesn't light up either. I determined that the wires going to the aux fuel pump are only delivering 1.9V while the working wires for the main fuel pump read 13V. The aux fuel pump works if I connect the 13V wires to it. These wires connect to the engine wiring harness in the cockpit tunnel (by the pilot's right knee). The connection there is also 1.9V.

Anyone had this problem or have any suggestions for troubleshooting?

thanks,
Patrick

Keep following that circuit back, from other side of switch, that is getting 1.9V, until you find where you are getting a full 13 V. Where the voltage changes and drops is where the problem is.