capacitor for electric fan?

My car has a large (OE) electric fan. Works well - is in excellent shape, but I notice that when it kicks on, its quite a draw (the OE relay is 40-50A) and you can feel the load on the car's system, idle, lights, etc. Perhaps this is a retahded idea, but would a capacitor like guys use for amps/subs help here? Thanks in advance.

They do not help on amplifiers, and they will not help your fan issue.

A cap does not reduce the current flow of a load. Nor will another battery (which is the superior solution to the cap for audio guys.) If you feel the load, it's because it's drawing huge Amps. A 50A load takes over 1HP from the engine which can often be felt at idle, hence why most vehicles increase their idle RPM with aircons on, or turn off the compressor at idle. I doubt that the engine is struggling due to low alternator output at idle (ie, a voltage drop, and the battery supplies the vehicle) because - except for points and old electronic ignitions - engine spark is usually voltage independent and should be fine down to ~8 or 9 volts as with most vehicle electrics and electronics.    But an alternator that does put out the required fan plus other load Amperage at idle doesn't overcome the "engine strain" at idle, in fact it will be worse (since the alternator supplies the load and not the battery). Caps are sometimes used for motors because of their impact on voltage readings, But those caps are usually small & placed at the (digital) voltmeter, not at the motors (heater fans, wipers, etc).

Since this is all OEM stuff, unless there's a specific problem related to many of your vehicles because of this current draw that you know about I wouldn't let it worry you. ALL of these cooling fans have huge onrush current draws and by now all car manufacturers know about it.

Thanks for the inputs. I'm not losing sleep over it....was just a curiosity thing. The radiator is huge so the fan doesn't run that much anyways.....just at idle when you really feel it. Thanks again.

Some mount 2 smaller fans with the option of running one or both. Also mounting closer to where the engine outlet enters the radiator else higher means greater cooling.