Low Coolant Sensor
Thread Starter
Intermediate
Joined: Mar 2003
Posts: 31
Likes: 0
From: Irvine ca
Low Coolant Sensor
I have an 89....how does this sensor work? Is it measuring temperature? Pressure? Also there is a "module" for this...how does it work?
Mine has been pretty goofy lately
and I'm wondering if replacing the sensor would help.
Mine has been pretty goofy lately
and I'm wondering if replacing the sensor would help.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
The sensor is a simple conductivity switch. When coolant drops below that level the light comes on.
To test the module, unplug the sensor and ground the wire. If the light still behaves badly, replace the module, else replace the sensor.
To test the module, unplug the sensor and ground the wire. If the light still behaves badly, replace the module, else replace the sensor.
Safety Car
Joined: Dec 2004
Posts: 4,088
Likes: 0
From: Poop land
Bump... I need to know how to replace mine too. Just started coming on last week and yet the coolant level wasn't low at all! Hmmmm.....
Can anyone take pics and give steps in removal and replacement?
Can anyone take pics and give steps in removal and replacement?
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Burning Brakes
Joined: Jul 2004
Posts: 956
Likes: 0
From: Mesquite Nevada
Originally Posted by SilverBeast
Coolant sensor on the 96 is on the overflow tank, on the passenger side firewall. I think the 94 is located there also. You can get to the sensor connector underneath the tank.
Melting Slicks
Joined: Oct 2004
Posts: 2,283
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From: Leeds Alabama
So what about the module?Where is it on a 89? BTW the most common fault of htis light coming on intermittantly is the sensor is mounted (l98's) HIGHER than the top of the radiator operating core (not heater core) if your coolant gets any air in it or is more than a half a cup low it will come on and off and you can top the radiator off till it overflows and not get it off....heres what you do...... Run the car to normal temp, if you have access to a ramp (like to change your own oil) run the front two tires up the ramp and put the front end of the car as high as you can, keep the car running with radiator cap off, idle the car up SLIGHTLY fill the coolant to the brim a couple of times, replace the radiator cap then take the car off the ramp. You allow the air to escape with the front end raised (car at angle) and can get a full coolant load. 
Le Mans Master
Joined: Mar 2001
Posts: 9,464
Likes: 1
From: Modesto CA
Originally Posted by corvette1989bham
So what about the module?Where is it on a 89? BTW the most common fault of htis light coming on intermittantly is the sensor is mounted (l98's) HIGHER than the top of the radiator operating core (not heater core) if your coolant gets any air in it or is more than a half a cup low it will come on and off and you can top the radiator off till it overflows and not get it off....heres what you do...... Run the car to normal temp, if you have access to a ramp (like to change your own oil) run the front two tires up the ramp and put the front end of the car as high as you can, keep the car running with radiator cap off, idle the car up SLIGHTLY fill the coolant to the brim a couple of times, replace the radiator cap then take the car off the ramp. You allow the air to escape with the front end raised (car at angle) and can get a full coolant load.
BTW: I thought the Sensor operated on pH level's, maybe I'm wrong...
Thread Starter
Intermediate
Joined: Mar 2003
Posts: 31
Likes: 0
From: Irvine ca
That is why I asked...if the sensor is a switch then they only needed a relay to turn on the low coolant light. Why a module? Does it have a timer which measures how long the switch is not grounded like in sudden acceleration?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Module is behind the bread box near the fuse panel. Easiest (at least for me) to access with the top of the dash off. Circuit is normally closed with the coolant at the correct level. If the light is on and the radiator is full, ground the harness lead and see if it goes out. If so, you need a new sensor. If not, the wire is open or the module is funky.
Module gets ignition power from the Gages fuse. Doubt it's blown or you would have other symptoms. Ground runs to the driver's side kick panel area. It's spliced into a ton of other stuff, so you would probably have other problems if it was out. The idiot light gets it's juice through the Security Indicator and is grounded by the Module. You allready know that that part is working because the light is coming on.
I don't know if the Module is available - Corvette Central might list it, but I haven't had any reason to check it - www.corvettecentral.com - Sensor is available. When I replaced the radiator, new GM, it came with it installed. Do get the air out of it when you fill it up as it (the air)will play havoc with the sensor and give you an intermittent light.
Module gets ignition power from the Gages fuse. Doubt it's blown or you would have other symptoms. Ground runs to the driver's side kick panel area. It's spliced into a ton of other stuff, so you would probably have other problems if it was out. The idiot light gets it's juice through the Security Indicator and is grounded by the Module. You allready know that that part is working because the light is coming on.
I don't know if the Module is available - Corvette Central might list it, but I haven't had any reason to check it - www.corvettecentral.com - Sensor is available. When I replaced the radiator, new GM, it came with it installed. Do get the air out of it when you fill it up as it (the air)will play havoc with the sensor and give you an intermittent light.
