The power distribution center, or fuse block, located under the hood houses most or all of the vehicleâs fuses and relays. It contains a relay for the ECM that is powered up when the ignition key is turned to the on position. This ECM power relay acts as a switch that supplies power to the ECM.
How to Tell When It's Time to Replace Your Water Heater. A water heaterâs lifespan depends on several factors, including water quality, water temperature, and maintenance. As such, lifespans vary anywhere from 8-15 years.
1 Remove old water heater (45-60 minutes). As easy as this sounds, thereâs really several steps that need to be taken to ensure safe removal -disconnecting the power source, draining the tank, disconnecting the water supply lines and the actual removal of the tank.  Position new heater in place (approximately 30 minutes).