Intermittent "Low coolant" light

[KVacek]

My '94 GT has been getting an intermittent "low coolant" light, but coolant level is OK. I've cleaned the sensor, cleaned the coolant reservoir, and it has fresh coolant. Is this a common problem?

I can't find any info on this sensor circuit - I assume it's read by the ECM, but I don't know what it's looking for - maybe conductance through the coolant?

The sensor is just two electrodes in the coolant - they're not obviously corroded and there's good continuity from each one to the connector, so I don't think there's a fault in it. Maybe some necessary plating on the electrodes has worn/corroded off?

Thanks!

Karl Vacek

 

[Joes95GT]

Let me guess, the light is probably on until the engine warms up, or it only comes on during very cold days? That is a big problem on most of our cars. Just get a new one from Ford.

Joe

 

[KVacek]

It goes on and off at any outside temperature, engine hot or cold, etc.

The dealer wants $90 for the part, special order. It's tempting to just pull the bulb.

Karl

 

[KVacek]

No rhyme or reason - goes on and off in hot or cold weather, hot or cold engine. Sometimes I don;t see it for days, then it's on and off, then maybe on non-stop for a day or two.

Dealer wants about $90 for the sender, special order. Tempting to just pull the bulb.

 

[Ice Hawk]

I have a 96 Thunderbird LX that has the same problem. Like Joes95 said, it only happens when the engine is cold and I am using the A/C or Panel for air. It will usually stay on until the engine warms up. I thought at first it was just cuz the liquid increased in density, or that it grew thicker, but now I am not for sure. Your problem sounds a little different. If it doesn't bother you too much, don't worry about it. Like you said, you checked the fluid, and it was fine, so unless it bothers you, ignore it. It would cost too much to fix such a minor little thing. It seems to be common on alot of mid nineties Fords. Hope that helps.

 

[sixty9boss302]

Mines been on for a good month and the coolent level is always fine when i check it. Eventually the bulb will burn out and i won't have to look at it anymore.

 

[Ice Hawk]

Wow, a month. It mustn't bother you too much. Eventually, yes it will go out, but it will be a long time. They are designed to come on and off for like freakin ever! So, continuois on, except when the car is off, that will take some time still. You could probably unplug the wire from the back of the light if you wanted to. I don't know how hard that would be. Do you really have a 69 Boss 302? If so, VERY NICE! Color?

 

[Slow5.0]

When my "low collant" light come out I need little bit collant, somehow I lose collant ONLY in winter never in summer , and leak is under radiator

 

[KingDiamond]

My low coolant light comes on whenever the temperature is under 40 degrees outside. After the engine warms up and I turn off the car and then turn it back on, the light is off.

 

[moneypit94]

I had the exact same problem as you KVaceK. No rhyme or reason it just did it every once in awhile. (I also found out if that light is on that my AC won't work.. I don't know why that is but as soon as i fixed it my AC worked) What i did to fix it was i made sure that the little prongs were clean (scratched them clean) Then i bent them together.. (They don't touch but they are pretty close. This fixed my problem... And to varify i pulled the sensor out of the water and the light came on again.

 

[sixty9boss302]

Ice Hawk - i wish i had a 69 boss but i don't , i made this name when i was 16 and all i knew was i had to get a mustang.
The light is pretty annoying. Maybe during spring tune up i'll try cleaning the tabs like others have said.

 

[94GTLaserRC]

We just did a post on this. It seems that coolan finds it's way out of the fill bottle when it's cold out. If the radiator level is ok, just fill the bottle to shut the light off. When it warms up, check, and you will see that it doesnt still do it.
RC

 

[mustanggt94]

When my "low collant" light come out I need little bit collant, somehow I lose collant ONLY in winter never in summer , and leak is under radiator

Mine does the exact same thing! Leaks only in the winter, but I don't drive my car in the winter anyway so it's all good for me.

My light also comes on frequently, which I only notice it when it's cold out also.

 

[hillie16]

My low coolant light comes on whenever the temperature is under 40 degrees outside. After the engine warms up and I turn off the car and then turn it back on, the light is off.

Same exact thing here.