You need to check OVP relay. It has a fuse on the top. If the fuse is blown, you will have problem starting up your engine. If the fuse is blown replace it and start the engine. If it blows again, repair short circuit. If the fuse is good you need to test the OVP relay. Disconnect plug from the ECU. Switch-on ignition, test voltage from plug term #1 to ground, it should be a battery voltage. If there is a battery voltage your OVP relay is good. Your problem is somewhre else and you will need to perform other test in order to troubleshoot your problem. If there is not a battery voltage, unplug OVP relay. Jump connector terminal 1 & 2. Test voltage on term # 1 of ECU plug, there should be battery voltage, if not repair open circuit. If you get a battery voltage at ECU plug term#1, test voltage at terminanls 5 & 6 on plug of OVP relay. If there is not battery voltage present, repair open circuit. In case when you will have battery voltage on terms 5 & 6 you will need to replace OVP relay.