Why doesnt the cooling fan come on on my 1993 mercury topaz
You just asked about the one circuit that gives this backyard mechanic nightmares(lol).There is a relay to turn fan on, but whether it is controlled by a simple temperature sensor/switch on the engine, or by your ecu (engine's computer) I don't know.
Until you get a definitive answer from one of our experts here, there is a simple test you can do to make sure fan motor is good. Unplug the connector for motor and check for corrosion in the terminals of the connector. Plug it back in. Look on the thermostat housing or just adjacent to it, for a single wire connector. This is the fan sensor/switch. Unplug it and turn key to on. Fan should start. Be careful of fan blades when key is on: It MAY come on any time key is on. If it doen't come on it may be a bad sensor in the switch-supposed to build resistance as coolant temp. increases, then at certain temp. will turn fan on.
So, fan on? Replace that switch you disconnected. Or, still no fan? Plug sensor back in. Turn key off. Unplug the fan motor again, and use jumper wires from battery to fan terminal connector, just long enough to verify if fan works or not. If fan motor is good, there is a problem with the temp. sensor, or the relay (probably located in fuse box by battery), or the associated wiring, or the computer (IF your fan is controlled by the computer). Then you have just inherited my nightmare. But if fan does not work, you have found the problem. Good luck.
Nov 11, 2011 |
1993 Mercury Topaz