spal power window kit connections

I'm looking to purchase one of the Spal power window kits. My question is, where is the best place to connect it to power? In the wiring diagrams on Spal's website they show it connected directly to the battery, but through a relay that is powered by the accessory lead. That way the windows only get power when the relay is activated by the key being turned. Is there any reason why you couldn't just connect it straight to the accessory wire coming off the steering column at the starter? 2007 Ford Ranger, by the way. --B

Here's a link to the wiring diagram in question: http://www.spalusa.com/pdf/33000030_SPEC.PDF#view=FitH --B

i don't recall how much current those motors use but being the nature of motors, they use a decent amount to function. you could use the accessory from the ignition but you run the risk of overloading the ignition switch's +12v circuit if say you have the blower on high while listening to the radio at a loud volume and have the wipers going, etc. i recommend just using a relay like spal says, i did that on the last spal kit i put in (planned on it anyway despite what spal said). also, with this said, i never looked up the current rating of the ford ranger ignition switch's +12v

I never bothered with the relay, direct battery or fusebox input wire. Most of my customers wanted them permanently anyway. You haven't stated what car but many acc systems wont carry the 25amp load with 2 windows working at once. 12V+ Constant fused, 25amps per pair to 30, Acc to 86, Ground to 85 and 87 to window switches. The RULE is to place as little load as possible on EXISTING FUSED CIRCUITS.