<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body dir="auto"><div dir="auto"><font face="sans-serif">Reading these posts on z fan Controller, it seems to me too many depending on the 'Undependable Age of Crap Electronics'. Forget all that.</font></div><div dir="auto"><font face="sans-serif"><br></font></div><div dir="auto"><font face="sans-serif">Randall's got it nailed, as I did way back in 1998. I added the biggest Hayden fan that still fit the TR4 radiator. Believe TR3 similar size.</font></div><div dir="auto"><font face="sans-serif">12" circular fan.</font></div><div dir="auto"><font face="sans-serif"><br></font></div><div dir="auto"><font face="sans-serif">Used standard adjustable Hayden temperature control switch with standard probe-Jensen Interceptor simple circuitry. Inserted probe gently between fins, upper left corner radistorAlways works. Now 20 years since installation. </font></div><div dir="auto"><font face="sans-serif"><br></font></div><div dir="auto">No electronic crap on my TR4. Functional electric cooling mod is practical but no need to exacerbate complexity.</div><div dir="auto"><br></div><div dir="auto">Sherman D Taffel, PhD</div><div dir="auto">Columbia MD & Goldvein VA </div><div dir="auto">TR4, 4 Jags (3 V12s-72-96), 5 Jensens (2 Interceptors & 3GTs).</div><div dir="auto">13 Americans ('36-'15)</div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div id="composer_signature" dir="auto"><div style="font-size:85%;color:#575757" dir="auto">Sent via the Samsung Galaxy S10, an AT&T 5G Evolution capable smartphone</div></div></body></html>