35 mph would probably be about right. As soon as I got the truck up above 25 miles an hour the temp gauge started dropping like a rock and went right back to normal real quick. I found a website that had plans for making a presure switch that will allow the electric fan to shut down when air presure reaches a certain amount. The recomendation is to remote mount it with a tube running out in front of the radiater area. Then when the car reaches a certain speed and air presure in front of the radiator builds up the switch shuts down the elctric cooling fan. I don't have the URL handy, I know they seemed to be selling the plans to build the switch yourself. I never followed up on it though. Mark Price mpriceATwestco.net Morgantown, WV 69 AMC rambler, 4.0L, EFI, 5 speed 65 Ambassador Conv, 327 AUTO, Basketcase 01 S-10 CREWCRAP 4X4 ---------- Original Message ---------------------------------- From: Tom Jennings <tomj@xxxxxxx> Reply-To: mail-From-mprice-westco.net@xxxxxxxxxxxx Date: Wed, 8 Jun 2005 08:57:15 -0700 (PDT) >On Wed, 8 Jun 2005, Mark Price wrote: > >> I installed an electric cooling fan on My S-10 in February or so this year. >> [...] > >I wish someone made an electric clutch, like an A/C compressor >clutch, that drives a water-pump mounted fan. Then you could >install a massively agressive pitch fan with enough reliable HP to >turn it -- but only when you needed it, with a thermostat. > >I always thought that on the later AMCs with TF autos, the TCS >(transmission controlled spark) swtich would be perfect for >disabling an electric fan. The switch closes (or opens, I forget) >at 35 MPH, pretty much when you're getting a radiator full of air >from forward motion alone. > > > > > >