<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_ym19_1_1486918541999_2908">Brian,</div><div id="yui_3_16_0_ym19_1_1486918541999_2908" dir="ltr">You are brilliant! I too have a marine engine compartment fan. Your use of a rheostat on that fan for circulation is a perfect idea. I am going to copy that idea but go a step further and use a PWM speed controller on it so I can reverse it. I use that fan for cooling the sub and periodic air circulation. Mostly though it is for bringing in fresh air from outside with a flexible hose. By reversing it, I can push inside air out or bring outside air in. </div><div id="yui_3_16_0_ym19_1_1486918541999_2908" dir="ltr">Hank</div><div id="yui_3_16_0_ym19_1_1486918541999_2908" dir="ltr"><br></div><div id="yui_3_16_0_ym19_1_1486918541999_2908" dir="ltr">I am a bone head! I left three wires exposed waiting for a new switch in my hand held motor control panel. They shorted and melted the feed power wire, now it is a full day job to replace the multi wire cable ;-( </div></div></body></html>