This weekend I did the fan modification that runs the fans on high for 30 seconds until I close a switch, and then runs the fans on a lower setting for ~10 minutes. It worked fairly well, but after a couple tests to make sure it would actually stop, my battery was dead.

Granted its probably the original battery on the car so I may need a new battery. But has anyone else had any problems with draining the battery by running the fans with the engine off?

 

Good question. I've gone through 2 batteries myself, but I suspect it's not only the fans doing it. Either way, the fact that the fans operate without the engine being on, means they are operating using the batteries power. This can drain the battery faster than normal, and along with it being old, can very well be your problem. There could be other reasons as well though. At worst, your battery has a dead cell, and you will need to replace it. Otherwise, see if you can get it recharged.

 

I've never had a problem w/ the battery dying from leaving the fans running for 10 minutes after shut down. My battery is pretty new though.
Try changing your battery. Go to Autozone and get a 51R series battery they have for Honda's. It will work fine our cars. It's like half the size of the stock battery and weighs a lot less. Only $40. Not a bad deal.

 

I did the fan mod a couple of weeks ago and have the same problem. I think my car has the original battery, so I am going to change it out. My plug wires need to be replaced, so I'll do that as well. Hopefully that will take care of it.
-Jayk, did you get a new battery? If so, did it solve the problem?

 

I had that problem as well. The battery liked to die after alot of short trips around town, with the fans running after shut down incessantly. I'd recommend getting a heavy duty battery like an Optima, and also only use the fan mod when it's needed.

 

When you use the fan mod after the car shuts down, for ten minute cool down, it is important to put the fans on low speed after 30 seconds(turn off the switch). If you don't do this, the switch stays on, and draws current until you try to start the car again. This will drain your battery, especially if you leave it over night, or don't drive the car for a couple of days.

 

I've been leaving the switch on over night and my battery seems to be fine.

 

You probably have a good strong battery. Don't go on vacation, and leave it on. Your battery will be dead.