Question about 1998 Mazda Protege
Hi, here is how your system works. The coolant temp sensor get's a reference voltage from the PCM and returns a voltage corresponding to the temp. The PCM then turns on the fan relay onve the temp reaches a certain level. If your coolant sensor is working properly (moving into red or light coming on), then the problem is with the relay, fuse, or the fan itself. Otherwise, it is the sensor.
If the sensor reading is bad, first check the connection to the sensor. If the connection is good, remove the connector and use an ohmmeter to check the resistance of the sensor. It should be as specified below. If not, replace the sensor.
If the sensor indications are good, try swapping the fan relay with another similar relay. The fan realy is usually in a box under the hood--sometimes on the passenger side in front of the shock tower. Finally, if both the relay and sensor are good, use a 12 volt test light or voltmeter to check for power to the fan connector when the engine is running and hot. If there is no power, check the wiring from the fan relay. If there is power, replace the fan motor.
Please let me know if you have any questions, and thanks for using FixYa.
Coolant temp sensor resistance:
-4°F (-20°C)-14.6-17.8 kohms 68°F (20°C)-2.2-2.7 kohms 104°F (40°C)-1.0-1.3 kohms 140°F (60°C)-0.50-0.65 kohms 176°F (80°C)-0.29-0.2 kohms
Posted on Mar 11, 2011
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Oct 31, 2017 | 1997 Mazda Protege
Sep 18, 2012 | 2000 Mazda Protege
Sep 05, 2012 | 2001 Mazda Protege
Aug 17, 2012 | 1998 Mazda Protege
Jul 21, 2011 | 1999 Mazda Protege
Jul 11, 2009 | 2003 Mazda Protege
Dec 23, 2008 | 1995 Geo Metro
Oct 18, 2008 | 2001 Mazda Protege
Oct 15, 2008 | 1998 Mazda Protege
1,824 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: