So quick question. Is there any benefits to leaving your electric fan run a few seconds when shutting your jeep or car off or is it just wasting energy.

 

In my opinion it is just a waste of energy.

 

With the engine off the water pump isn't pumping anything so leaving the fan on doesn't do much.

 

thats what i figured only reason i see is maybe if you have heat soaking issues itll blow away some hot air but still

 

You could throw a small capacitor inline to the 12v which lets the fan run for a bit then stops.

 

It will contribute to climate change.

 

A capacitor inline will prevent the fan from running at all.

A capacitor to ground will keep the fan running for a bit, but it would have to be a massive capacitor to keep it running for long enough to do any good.

In fact, it would have to be pretty big to keep it running even long enough to notice it.

If you are having boil-over problems after shutting down, yes, having your fan run an extra minute or two can be beneficial. To do that you need to build a timer circuit. It's not hard to do. Or you can buy one ready made.

But first make sure your cooling system is in good shape. If it is, you really shouldn't need anything else.