If the automatic windows and gauges and AC only work when a 1988 Toyota Camry LE is in reverse is the problem electrical?

Yes, and most likely due to a faulty switch associated with the transmission. If you obtain a Chilton or Haynes (on-line, ebay, or at your local autozone/advanced auto parts store)repair manual for your vehicle, you can view the schematic that will assist you in troubleshooting the problem.