Suv wouldn't start

Suv wouldn't start. Took it to mechanic who replaced coil and wires (he said they were rotten). Cost nearly 700.00 with the tow. Have been driving it for 2 days. The climate controls don't work right. And now it wants to stall intermittently while driving. Thought it was the fuel filter or something fuel related but the driver said that when it choked the power spiked and dropped on the guages. Now I think it is something power (electrical) related. Do you have any suggestions. The mechanic is unavailable and I don't think it is safe to drive