Electrical failure everytime it rains or water reached the enginei receive this error massage: ETS ERROR can somebody help? thx in advance

Assuming the battery is ok, no electricity is reaching the car circuits. First thing I would check is to make sure that your battery connections are good and tight. Next item is the battery properly grounded to chassis? If so, they you will have to get a schematic to trace the wiring and see just where the flow of electricity can be interrupted.

The electric fans operate when the coolant temperature reaches a certain level. There is a temperature sensor that triggers the fan operation. If the sensor is faulty or has failed completely the electric fan will not start.
That is the first place to look if you have checked both the fuse and the relay that covers the fan. You have not mentioned the relay but if that is faulty the fan will not work either.
Check your owners manual. That will show you the location of the relays (as well as all the fuses).

Do not delay getting the problem addressed by a competent professional as allowing the engine to overheat WILL cause very expensive engine damage (such as blown cylinder head gasket and a cracked cylinder head) which will be many,many times in repair and parts costs over the cost to you to fix the issue with the cooling fan.

When it is raining the water is coming in through the radiator and is causing electrical shorts in the ignition system. Use a water repellent spray (silicon spray) on everything related to the ignition (HT leads plug lead rubbers ) coils and distributor cap if applicable. When you drive through puddles the water is deflected into the mudguards and is not likely to reach the engine compartment.

have u checked the water pump? the gasket could be bad! if that's not the problem check the thermostat. they also make a dye u can poor in the radiator called auto pro uv dye. you can get it at advanced auto parts store! use a black light and it'll show you where the leak is coming from! hope this helps!

the car is past its sell-by date ,1974 ?? the door locks work on vacumn not electric so perhaps the rubber tubes are perished

If you use a guitar string to run down the drain hole followed by compressed air, you should be able to clear the clog.

Obviously water is the cause. Make sure all hood seals and underbody splash shields are in place, check firewall main connector for security. After it rains (without driving it in rain) check floor mats inside for water. A possible windshield or dash leak is allowing water into electrical area near instrument cluster (windshield may need resealed). Lift hood and look for water on any electrical connections disconnect dry, and seal with tune up grease from parts store.
Good luck

This could be fuel not reaching the injectors. Check for a clogged fuel filter or fuel lines. Dirty or clogged fuel injectors. Also difficulty starting after rain can be caused from old plug wires. I hope this helps.

has the ac blower motor been under dash been replaced ? my brother replaced mine but didnt rain for a while so when there was standing water in the floor board didn't even think about it but after a small wreck and in the process of replacing right fender and hood had to take off cowl vent panel so decided to look and see if could find leak and sure enough there is a rubber seal around the hole the blower motor fits in and it was not seated correctly reached down seated no more leak hope this help worth checking any way

the wheel speed sensors may need adjustment on the rear