electric fan not working ?

[Armageddous]

I have a 1990 Mustang LX 2.3l 5spd with an electric fan. the fan works, I have it hooked up to my coil wire for constant power right now, and thats sort of ghetto.
the engine can be boiling over and shooting steam out of every hose it has, and it still doesn't give power to the fan from the original connector.
where is the temperature sensor located? the book says it sould be inside the top rad hose.. I think it lied. the only other thing that looks like one is in the middle of the intake manifold.
is the sensor for the gauge the same for the fan? any relays I should look for?
anything would help. also, my heater core is blown, and my hose is looped. the 3/8 hose is plugged off. I had a suspicion the sensor requires this hose.. but I dont feel like putting in a heater core in if its not going to do anything.
thanks.

 

[Red_LX]

What 3/8" hose are you talking about...the one that runs around the back of the engine to the intake manifold? If you plugged that one you better hook it back up. Without that there's no coolant flowing over the Engine Coolant Temp sensor (which is in the lower manifold), and I don't remember if that turns on the fan or not, but if it does it probably wouldn't with no coolant flow over the sensor (wouldn't be getting an accurate reading). Alternatively you can relocate that sensor and plug the hole in the intake.

 

[rd]

Several things to check here. There are 3 coolant temp sensors, one each for the gage, computer and fan. The sensor for the fan is at the rear drivers side of head, I think. (Probably need to verify, I am writing from memory)

The fan is not directly controlled by temp sensor, but by a little electronic box called a CCRM or IRCM, depending on the year. 89's have a CCRM, and its mounted under the dash to the left of the steering wheel. It has battery power in, and the fan relays. It takes the signal from the temp sensor, as well as the ac system controls, and turns the fan on based on temperature or ac demand. All of the power for the fan motor has to run to this module, through the relays, and then back out the wire to the fan.

They seem to have a problem with the power connection, either at the power in or the output to the fan. The current flow is enough to heat up the plastic connector and the plastic box that holds the circuit board and that the connector plugs into.

Mine melted the wiring at the connector and the connection got so poor the fan would not run in ac or for just cooling. I bought a new module and a connector repair kit, and the new connector melted in a week. I then put on another new connector and just added a couple 30 amp relays for the fan, powered by the battery, and controlled by the former fan power wire from the CCRM. Its worked fine for a year or more.

Some of the later ones, after 89, have the module mounted on the pass inner fender under the hood, which should make it easier to check. It is called the IRCM, and also has the fuel pump relay, I believe.

 

[mg man]

I have a 90 lx hatchbatch fixing up the fanswitch is in the lower intake toward the firewall. It has 1 push on wire on it. Ground that wire will tell you if sensor is bad fan on sensor bad fan off check module under steering column wires will look burnt. On my 89 turbo I wired a relay a this point to take the amps off the board also relay is cheaper than board hope this helps