JohnW
Mar 19th, 01, 06:21 PM
92 L98. Primary fan will not run at 230 degrees. Primary fan will run if ALDL terminal grounded or fan relay from ECM grounded or AC is on. Replaced coolant temp sensor. Coolant sensor reads 150 ohms at 230 degrees. CTS voltage does not drop below 5 volts at ECM to trigger ground in ECM for fan relay. Replaced fan switch. Secondary fan will run if AC pressure switch is jumpered or fan switch is grounded. Swapped ECMs - no help. What's up?
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JohnW
dale68z
Mar 19th, 01, 07:02 PM
Are you sure the temp is 230,did you check it with an infrared?Everything sounds good,should work.I owned a 85 corvette,the fan didn't run till 236.I have all my coolant fan info at the shop.
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68 z28 ,68 rs 327 ,73 454 vette, 2 goofy kids
dale68z
Mar 20th, 01, 07:03 PM
I have some info.The primary fan is computer controlled.It should turn on at 224,the computer temp sensor,is the sensor for this fan.Of course AC turns it on also.The sec. fan turns on at 234ish,is controlled by the coolant switch,and AC pressure.The fans turn off at 40 mph,unless it's overheating.I dont know the ohms on the sensor.I would check,with a scan tool,the coolant temp.Also the vehicle speed.The sec. fan relay ,as I understand,is direct wired to the coolant switch.By jumping the ALDL you've confirmed the fan motor,relay,and computer.Something else is causing the problem.
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68 z28 ,68 rs 327 ,73 454 vette, 2 goofy kids