Please help identify this part
Thread Starter
Racer
Joined: Oct 2002
Posts: 442
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From: Union ME
Please help identify this part
I have a 1984 Corvette. On the passenger side, at the same level as the spark plugs, is a sensor. It appears to screw in, similar to the spark plugs. The wiring coming off this sensor does not attach to anything. It is stripped bare. Please help me identify what this part is, and where the wiring should connect. I get readings for engine coolant temperature, oil temperature, and oil pressure that all appear to be accurate. It also goes closed loop at about 140 degrees, which seems about right. Please help!
Racer
Joined: Dec 2003
Posts: 277
Likes: 3
Originally Posted by efweber
I have a 1984 Corvette. On the passenger side, at the same level as the spark plugs, is a sensor. It appears to screw in, similar to the spark plugs. The wiring coming off this sensor does not attach to anything. It is stripped bare. Please help me identify what this part is, and where the wiring should connect. I get readings for engine coolant temperature, oil temperature, and oil pressure that all appear to be accurate. It also goes closed loop at about 140 degrees, which seems about right. Please help!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Between the #6 and #8 plugs is the fan temp switch. The ECM has no control over fan operation on an '84. The wire is .8 brown, circuit #335. At a connector it is joined by a .5 tan wire from the A/C compressor. From the other side of the connector, circuit #335 continues as a .5 dark green/white wire to terminal "B" on the fan relay. The fan relay is located on the left inner wheel well, below the front of master cylinder. When the switch reaches is designed temp, it closes and grounds the primary side of the relay, activating the fan. Switching on the A/C grounds the same circuit, as the wire routing above explains.
RACE ON!!!
RACE ON!!!
Thread Starter
Racer
Joined: Oct 2002
Posts: 442
Likes: 0
From: Union ME
Originally Posted by CFI-EFI
Between the #6 and #8 plugs is the fan temp switch. The ECM has no control over fan operation on an '84. The wire is .8 brown, circuit #335. At a connector it is joined by a .5 tan wire from the A/C compressor. From the other side of the connector, circuit #335 continues as a .5 dark green/white wire to terminal "B" on the fan relay. The fan relay is located on the left inner wheel well, below the front of master cylinder. When the switch reaches is designed temp, it closes and grounds the primary side of the relay, activating the fan. Switching on the A/C grounds the same circuit, as the wire routing above explains.
RACE ON!!!
RACE ON!!!
Melting Slicks
Joined: Sep 2003
Posts: 3,326
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From: I live at www.domesticlugnuts.com I sleep in PA
Originally Posted by efweber
O.K., great information. Now, what is the impact of not having this sensor?
Race Director
Joined: Dec 2000
Posts: 17,551
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From: El Paso Texas
Originally Posted by efweber
O.K., great information. Now, what is the impact of not having this sensor?
If your fan is running continually, somebody has grounded the wire that would ordinarily connect to the switch. This is a cheap alternative to replacing a faulty switch, but will dramatically shorten the life of your fan motor. I would reconnect everything correctly, and see if your fan comes on at 225 like it's supposed to.
