Sensor Question
Thread Starter
Instructor
Joined: Nov 2005
Posts: 161
Likes: 0
From: Pittsburgh Penna.
Sensor Question
I was redoing the front suspension on my 85 and noticed a disconnected wire coming from a sensor on the passenger side of the block between the rear two spark plugs. Can someone tell me what sensor this is? Also there are two wires coming from it. The black one is disconnected. Is this just a ground?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Do you have a aux fan behind the front bumper? That is the aux fan switch.
On the 85 the fan switch is located between #6 and #8 spark plugs. The engine temp sender for the IP is located between #1 and #3 spark plugs.
Starting in 86 both of these swapped locations. Also, not sure about the 85, but the 86 has one wire going to it (green with white stripe).
Does the "sensor"/switch look like this?
On the 85 the fan switch is located between #6 and #8 spark plugs. The engine temp sender for the IP is located between #1 and #3 spark plugs.
Starting in 86 both of these swapped locations. Also, not sure about the 85, but the 86 has one wire going to it (green with white stripe).
Does the "sensor"/switch look like this?
Last edited by RRT vette; Jul 9, 2007 at 11:22 PM.
Thread Starter
Instructor
Joined: Nov 2005
Posts: 161
Likes: 0
From: Pittsburgh Penna.
Its the right location but the there is a black plug that comes off it. Whoever had the car before me had spliced a wire to the black wire coming off the sensor and had a crimp on wire end that looks like a screw was being used to ground it. Also I do not have an auxilary fan.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
The fan switch in RRT vette's photo is actually in the head, not the block. Those bolt heads in the pic are head bolts. You can see that the #8 spark plug is slightly below the switch. The 1985 was the only C4 with an ECM controlled main fan that used a fan switch whether it had an auxiliary fan or not. On '85 cars with no aux fan, the switch acts as a back up to the ECM. Because you don't have the aux fan all but the first line of RRT vette's post is correct. The wire color on the '84 is brown at the switch and green at the fan relay. I would not expect the factory wire at the switch to be black on the '85. The fan switch works by grounding the wire attached to the connector, at the designed temp, through the shell of the switch to the head. Any additional ground connected, there, would only serve to bypass the switch and keep the fan running constantly. That wastes gasoline and puts unnecessary wear and tear on the fan motor.
RACE ON!!!
RACE ON!!!
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Intermediate
Joined: Jun 2007
Posts: 34
Likes: 0
From: Burton MI
Okay, I have a picture of the sensor I was talking about on my 87 but can't figure out how to attach it. It is located on the drivers side between the two front spark plugs. The connector clip is broken, which I ordered for $4.99, but I can't find anywhere that tells me what that sensor is. Your thinking it is the Aux. Fan sensor??? It's only one green wire and connects directly to the alterater harness, So I'm thinking your right on.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by dans87vette
It is located on the drivers side between the two front spark plugs. The connector clip is broken, which I ordered for $4.99, but I can't find anywhere that tells me what that sensor is.
Originally Posted by dans87vette
Your thinking it is the Aux. Fan sensor??? It's only one green wire and connects directly to the alterater harness, So I'm thinking your right on.
Originally Posted by RRT vette
On the 85 the fan switch is located between #6 and #8 spark plugs. The engine temp sender for the IP is located between #1 and #3 spark plugs.
Starting in 86 both of these swapped locations. Also, not sure about the 85, but the 86 has one wire going to it (green with white stripe).
Starting in 86 both of these swapped locations. Also, not sure about the 85, but the 86 has one wire going to it (green with white stripe).
RACE ON!!!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Instructor
Joined: Nov 2005
Posts: 161
Likes: 0
From: Pittsburgh Penna.
Thanks for identifying the sensor. I'll check the FSM to see where the wires are supposed to go. Whoever had the vette before spliced a brown wire to the black one coming from the connection. The end of the spliced wire has a crimp on connector that has part of it broken off. Not sure if this a ground wire or what
Intermediate
Joined: Jun 2007
Posts: 34
Likes: 0
From: Burton MI
It should say or show in your FSM. How could you possibly order a connector to fit a "mystery" device (sensor or switch)?
He isn't thinking it is, he has said that it is the fan switch. He is correct. He posted a picture for the OP and in response he stated that:"Starting in '86" includes the '87.
RACE ON!!!
He isn't thinking it is, he has said that it is the fan switch. He is correct. He posted a picture for the OP and in response he stated that:"Starting in '86" includes the '87.
RACE ON!!!
http://www.ecklers.com/product.asp?p...5&dept_id=1129
Intermediate
Joined: Jun 2007
Posts: 34
Likes: 0
From: Burton MI
The manual I have does not identify it. I posted a pic of it weeks ago on another vette forum and three people said it was the cluster temp sensor. I compared what it looked like to the switches at Ecklers and found the plastic connector that looked identical. The connecter said it was for temp/knock sensor connection. Bought it and it was identical, put in on and works great. So maybe Ecklers should name it temp/knock/Aux Fan connecter so I will know next time. WORKS GREAT, thanks for the help.
http://www.ecklers.com/product.asp?p...5&dept_id=1129
http://www.ecklers.com/product.asp?p...5&dept_id=1129
Opps, forgot.........are you okay with it now????????????
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
dans87vette, I see you posted you have an 87 but your profile says 88. Anyhow, Ecklers has it wrong. That connector you posted is for the knock sensor or auxillary fan switch (they use the same). The sender for the dash gauge has a spade connector, like in post #6. Not sure what is going on there.
The sender for the dash gauge only sends info to the dash. There is also a different temp sensor located in the front of the intake manifold that sends resistance changes, due to engine temp changes, to the ECM.
The sender for the dash gauge only sends info to the dash. There is also a different temp sensor located in the front of the intake manifold that sends resistance changes, due to engine temp changes, to the ECM.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Exactly!1984 and 1985, fan switch on the passenger side, all cars. IP gauge sender, driver side.
1986 through 1989, Fan switch on the driver side, cars w/aux fan, only. IP guage sender, passenger side.
Fan switch, mushroom head connector. Gauge temp sender, straight blade spade lug connector.
RACE ON!!!
Intermediate
Joined: Jun 2007
Posts: 34
Likes: 0
From: Burton MI
dans87vette, I see you posted you have an 87 but your profile says 88. Anyhow, Ecklers has it wrong. That connector you posted is for the knock sensor or auxillary fan switch (they use the same). The sender for the dash gauge has a spade connector, like in post #6. Not sure what is going on there.
The sender for the dash gauge only sends info to the dash. There is also a different temp sensor located in the front of the intake manifold that sends resistance changes, due to engine temp changes, to the ECM.
The sender for the dash gauge only sends info to the dash. There is also a different temp sensor located in the front of the intake manifold that sends resistance changes, due to engine temp changes, to the ECM.
Thanks for the help, I'm now "unconfused" no thanks to Ecklers.......which by the way are supposed to be the "Corvette Headquarters" for parts and that wasn't the first problem I've ran into using them since purchasing my C4.