I think electric fans are great, I have already converted my jeep, and the 300cd is next...

But I would not use those plastic mounts, I don't trust them. I would fabricate a bracket that mounts to the body and/or the original fan shround mounts.

Also as someone previously mentioned I would either upgrade the alternator or add another battery.

additionally I would wire a manual override, so that I could turn on the fans at my discretion.

Finally, I prefer 2 smaller fans as opposed to one large one, this gives more cooling options and also allows coverage of the oil cooler as well as the radiator.

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Cheers,
Robert