A week ago both front and rear washer pumps stopped working on my '07 Trailblazer. Both wipers work, the washer fluid reservoir is full. I replaced the front pump, blew out the lines, checked fuses, checked for a good ground and even switched out the relay with another working one. I checked for power going to the pump while initiating the wash cycle and I couldn't verify any. I'm at a loss of what to do next. I find it hard to believe both switches would fail at the same moment. Any advice?