Fan control is accomplished in two ways. The fan always runs when the air conditioning compressor clutch is engaged. In addition to this control, the fan is turned on by the temperature of the coolant which is sensed by the coolant temperature sensor which sends the message to the on-board computer. The computer turns on the fan through the fan relay. Switching through the on-board computer provides fan control for the following conditions.The fan will not run during cranking until the engine starts no matter what the coolant temperature is. Fan will always run when the air conditioning clutch is engaged. On non-air conditioned vehicles or with air conditioning off the fan will run at vehicle speeds above about 40 mph only if coolant temperature reaches 230°F and will turn off when the temperature drops to 220°F. At speeds below 40 mph the fan switches on at 210°F and off at 200°F. There also is included a method to help prevent "steaming" (water vapor evaporated by hot water circulating through the radiator evaporating moisture on the outside of the radiator and when there is no ram air to blow it under the vehicle) the fan will run only below 60°F ambient, from 100°F 195°F coolant temperature only at idle, and zero vehicle speed and then only for three minutes.
If it were me, I'd want to do away with the Chrysler ECM. You could rig up a fan control system without that kit. Just get a N/O coolant temp switch and wire it up to the control side of a relay that turns the fan on. Might have to get creative with the install of the temp switch...
thank god for liquid tape makes it easy to splice into factory wiring and not wreck it all :lol: looks like everything is moving well Arb! does your van have dual rad fans or just a single? (i think our '94 had dual but can't remember)if the fan is a three prong you could probably swap in a vw relay unit to control it, and use the head temp switch.
Wow what a project!!! I like the liquid tape. Real clean. Nice work.