I have a '49 ford truck, w/350 v8 Chevy engine. The fan is currently hot wired straight to the battery. How do I connect it to the ignition so the fan goes off when I shut off the engine?
a few options, You could get a 'fuse tap' and clip it into an existing fuse on the load side of fuse- which is the side that the power is fused, it will not have power unless the fuse is in place-(remove fuse then use test lite to verify) Then you can connect your fan power, use a fuse for an option that is either used rarely or not being used or you can wire to the starter solenoid -there is usually a terminal that will test hot only with ignition on. or The older ignition switches have multiple terminals, where you can test and see which one goes on and off with the ignition in run position(it would be best to be sure it does not power up during 'start 'up so you don't lose any cranking power. Another option which may be the best is to leave it wired as is but be sure it is protected by a fuse, and add in a 'thermo switch' You can get these from J C whitney , It is a switch that will wrap or attach around a heater or radiator hose that will turn ON the fan At a certain temperature and off after it gets below that temp. It is a momentary control by temperature. This can also be used if you wire through ignition so it will not be On all the time with the ignition but only when the temperature switch calls for it . if not wired through ignition it would work to cool down the radiator when you shut down too! , But if you select a too low temp. switch it could stay on very long and drain battery. to locate hot wires, use either a multi tester - or a test light with ground clip. i hope this helps
Your going to have to wire into the fuse box or into a wire that shuts off when you shut the ignition off.
you can hook into the voltage regulator, mounted on the inside fender well. you will need to find which terminal is only hot with the ignition on. but i would recommend putting a fuse in the line. but you wouldnt have to run wiring through the firewall and to the fusebox this way.
take a piece of 16 guage covered wire and run it from the fan to a fuse, thats hot only when the switch is in the start and run position and take another wire and run it from the other wire from the fan to a good ground. you might have to use a test light to determine which wire is hot, or you could just use a toggle switch and run 1 wire from the battery to the toggle switch and the other wire from the fan to the toggle switch, and when you start your truck, just throw the switch and when you stop, throw the switch off.i did that alot, when the fan wouldnt come on.
