troubleshooting electrical line on gas range
We have a 22 year old house, bought it about 5 years ago. I believe the original owners had an electric stove and replaced it with a gas stove at some point. I bought a new gas stove about 3 years ago to replace the gas stove that came with the house. Last week, the stove stopped working (electrically)...there is enough power to light the digital clock but that's about it...the electric ignition on the range and the oven does not work, and the oven light does not work. At first, I thought it was a bad stove, but I plugged it into another 115 outlet with an extension cord and it all works fine, so it seems there's something wrong with the dedicated outlet behind the stove. I've checked the voltage in the outlet and it reads 119.6 volts.
I went under the house to look at the wiring and found a big wire going from the circuit breaker (50 amp double pole) to the stove...it's a 3-wire 240V line with two insulated wires, and one bare wire...thus my belief that there was originally an electric stove. Whoever re-wired the 115 outlet for the gas stove used a wire nut to connect the black and white wires from the 115 outlet to one of the insulated and bare wires, respectively, of the 240 line. The other insulated wire of the 240 line is just wrapped in electrical tape. The ground wire from the 115 line was basically just sitting inside the 115 outlet box (metal) on one end and not connected to anything else on the supply end. There was a small (maybe 20 ga.) green wire that was screwed to the outlet box and then connected to a water line (copper pipe) under the house...I guess that is some type of dedicated ground line since there is no ground wire in the 240 line? I am assuming whoever wired this did it correctly as it has seemingly worked for a long time now, but for whatever reason, it doesn't work any more. Any ideas or suggestions as to how to troubleshoot this? Thanks.