no cooling fan, '90 Plymouth Grand Voyager
#1
no cooling fan, '90 Plymouth Grand Voyager
The cooling fan on my wife's '90 Grand Voyager (3.3l v-6, 4-speed auto trans, air conditioning) has quit working. The motor itself ( it's the one on the radiator, not the condensor) is fine; I jumped power to it and it started and ran fine. The relay is okay, too; I jumped the ground terminal straight to ground, the relay clicked shut and the fan roared to life. That leaves the control mechanism. I get different stories based on which parts house I talk to. One says the relay is controlled by the computer/PCM/ECM, another says it's done by a sender/switch in the coolant stream. I found the sender for the temperature gauge, with just one wire. There appears to be another sensor/sender behind the thermostat housing, with at least two wires. Could this be the culprit, and does it send a temp signal to the PCM so it can decide when to ground the cooling fan relay? Thanks for any/all input - Chris
#2
They are both right. The coolant temp sensor sends the data to the computer and the computer sends the command for the ground to the relay. To test this part, unplug the 2 wire temp sensor with the engine running and the fan should start. It should also start when the A/C is turned on. To verify what data is getting to the computer, you would need a scanner to monitor the temp input and the "fan on" command.