2003 CIVIC 2DR EX 1.7L D17A2 Coolant Fan Stuck on
#1
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2003 CIVIC 2DR EX 1.7L D17A2 Coolant Fan Stuck on
Hi everybody! So my 2003 CIVIC 2DR EX 1.7L D17A2 has the Coolant Fan Stuck on. (not the AC fan).
When I disconnect the coolant sensor (up by the thermostat) the fan turns off. Does this mean that the sensor is bad and that the relay is not causing the fan to stay on? (the engine has been off a while and never overheated)
edited
When I disconnect the coolant sensor (up by the thermostat) the fan turns off. Does this mean that the sensor is bad and that the relay is not causing the fan to stay on? (the engine has been off a while and never overheated)
edited
Last edited by alex_nyc; 06-13-2015 at 07:30 AM.
#2
If you think a good mechanic is expensive, try hiring a bad one
Re: 2003 CIVIC 4DR EX 1.7L D17A2 Coolant Fan Stuck on
When I disconnect the coolant sensor the fan turns off.
#3
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#4
If you think a good mechanic is expensive, try hiring a bad one
Re: 2003 CIVIC 4DR EX 1.7L D17A2 Coolant Fan Stuck on
I have a diagram that shows it turns on the fans at 199*F.
The scanner should not be your bible on this one, the temp sensor it reads is temp of coolant exiting the engine (upper hose).
The fan switch senses the temp of coolant exiting the radiator (lower hose).
They can be quite different temperatures during normal use.
HTH
The scanner should not be your bible on this one, the temp sensor it reads is temp of coolant exiting the engine (upper hose).
The fan switch senses the temp of coolant exiting the radiator (lower hose).
They can be quite different temperatures during normal use.
HTH
#5
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Thread Starter
Re: 2003 CIVIC 4DR EX 1.7L D17A2 Coolant Fan Stuck on
I have a diagram that shows it turns on the fans at 199*F.
The scanner should not be your bible on this one, the temp sensor it reads is temp of coolant exiting the engine (upper hose).
The fan switch senses the temp of coolant exiting the radiator (lower hose).
They can be quite different temperatures during normal use.
HTH
The scanner should not be your bible on this one, the temp sensor it reads is temp of coolant exiting the engine (upper hose).
The fan switch senses the temp of coolant exiting the radiator (lower hose).
They can be quite different temperatures during normal use.
HTH
thanks
Last edited by alex_nyc; 06-13-2015 at 08:02 AM.
#6
If you think a good mechanic is expensive, try hiring a bad one
Re: 2003 CIVIC 4DR EX 1.7L D17A2 Coolant Fan Stuck on
It's the one you unplugged that got the fans to shut off.
If you were to study how the thermostat housing is constructed (plumbing of the water pathways) it contains inlets and outlets for both engine and radiator all in one unit. The smaller sensor on top measures engine temp for the computer to use (and would set a code if left unplugged), the sensor pointed toward the front senses the temp of water exiting the radiator and controls the fan.
#7
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Re: 2003 CIVIC 4DR EX 1.7L D17A2 Coolant Fan Stuck on
Don't overthink this just because I ramble about what's there LOL
It's the one you unplugged that got the fans to shut off.
If you were to study how the thermostat housing is constructed (plumbing of the water pathways) it contains inlets and outlets for both engine and radiator all in one unit. The smaller sensor on top measures engine temp for the computer to use (and would set a code if left unplugged), the sensor pointed toward the front senses the temp of water exiting the radiator and controls the fan.
It's the one you unplugged that got the fans to shut off.
If you were to study how the thermostat housing is constructed (plumbing of the water pathways) it contains inlets and outlets for both engine and radiator all in one unit. The smaller sensor on top measures engine temp for the computer to use (and would set a code if left unplugged), the sensor pointed toward the front senses the temp of water exiting the radiator and controls the fan.
#8
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Thread Starter
Re: 2003 CIVIC 2DR EX 1.7L D17A2 Coolant Fan Stuck on
I replaced the defective coolant sensor with a new $6 pepboys one and now the fan comes on like it should. It also runs cooler as per the gauge indicator.
Thanks for your help!
Thanks for your help!
Last edited by alex_nyc; 06-17-2015 at 12:49 PM.
#9
If you think a good mechanic is expensive, try hiring a bad one
Re: 2003 CIVIC 2DR EX 1.7L D17A2 Coolant Fan Stuck on
$6 ??? I guess if it works more than a week you got your moneys worth LOL
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