Looking to install a couple of small(30mm/30mm/10mm) 12 volt fans into a pair of Aristo Craft G Scale GP40's and a USAT G Scale NW-2 for starters. I've had them fail, when decoder went into thermal shutdown. Decoder then began speaking, stating, Temperature 98*C. Would do this about every 2 minutes or so, until decoder reset, after sitting for up to 30 minutes or more, to cool down. Finally restarting around 80*C. Looking to use the Smoke switch on the locomotives to power the fans, since I don't use the smoke units. Just need to find out what the voltage is at the On/Off switch. Thought I'd ask here first, before asking Dad where his meter is, so I can have voltage checked. Have been wanting to do this project for several years now! Hope to order the fans shortly. I'll do the same to the K-27 IF I can get the counterweight problem fixed. And maybe a couple of other units later. Namely, the SD70MAC and eventually, the PA, once I get Airwire and Sound added! Any information appreciated. Thanks.