Just installed a fan equipped oil cooler. I need to power the fan with an ignition switched 12 volt power source. Where is the best place to do that? Thanks for the help. Im hopefully looking forward to cooler temps

add a relay powered from the battery and use the coil + to switch it on/off.

I just want to find a wire to patch into

Like somebody already said, hot from the battery to a relay, trigger from the coil. Ground it through the thermoswitch you installed in the oil line so the cooler only runs when you need it. Don't want to EVER overcool the oil.

The Cap'n

First, where is the cooler installed? How about a picture?

Second, is there an oil thermostat installed?

My fan is low enough amps that I tied in to the fuel pump with a thermostat inline to trigger it.

Like this: http://www.etrailer.com/Radiator-Fans/Derale/D35022.html

There is no circuit on a 914 that can handle the extra load from a fan. I'm assuming your fan draws 5 amps or more. Install a relay and be done.

Relay it is !!

what is the type of relay I should use. Im new to relays

Here is a great relay book/pdf. download it and save it!

http://www.partsexpress.com/pdf/500-001.pdf

I got everything wired up but only can find a 12v 30 amp relay . the thermoswitch says it has a 15 amp max continuous. can I still use this relay. It seems all the relays a 30 amp I cant find a 15 anywhere

Thats MAX amps it will work fine as long as the source is properly fused!

That's "capacity", meaning you can us "up to" 12V-30A pretty safely. I use 40A for most applications, cause they're readily available from Bosch and other VW/Audi and Porsche parts suppliers.

The Cap'n

I bought one of these: ThermoSwitch Relay for a non-Porsche application.

The thermoswitch is adjustable, the relay is 40A, it has output leads for two fans, and includes the remote thermo sensor. Price is right.

It also includes an 'override' lead that's traditionally wired to an AC clutch but can be used for anything you like.

I ran my oil cooler thermostat from unswitched relayed power, that way it will run on after the car is turned off until it is cooled, usually only takes a minute or so.

I run mine thru a thermostat controlled, fused switch directly from the battery.