Coolant sensor

[Vohaul]

Argh.....93 aaz jetta
The coolant sensor on my dash won't stop flashing.... Level is fine.... Temp is fine, car has power, no issues except the stupid light.... Replaced the overflow tank... No difference....

Does the plug going into the overflow tank on these go?

Thanks

Paul

[wolf_walker]

Did they have that coolant water/antifreeze ratio sensor in that model?  Seems like my 85 had that going on way back.  Little sensor with two pins in the coolant tank.

[Vohaul]

Did they have that coolant water/antifreeze ratio sensor in that model?  Seems like my 85 had that going on way back.  Little sensor with two pins in the coolant tank.

ya, i think thats the one....sensor is part of the overflow tank...with a plug going into the top of the "dome"..i thought it was just a coolant level sensor...not a ratio

Drives me nuts...

This morning..start car...flashing...go to gas station...turn off...start car...no flash...1 hour drive..no flash...go for lunch...flashes again....and so on....

[wolf_walker]

I went through that years ago, freaked me out because I didn't have anyone to tell me it wasn't something terminal.
The A2 sensor is cheap, need o-ring too, if you haven't changed your coolant with a good mix it might be warning you
about something valid.

[Vohaul]

I went through that years ago, freaked me out because I didn't have anyone to tell me it wasn't something terminal.
The A2 sensor is cheap, need o-ring too, if you haven't changed your coolant with a good mix it might be warning you
about something valid.

I thought the sensor was part of the overflow tank itself?

[wolf_walker]

Not in the 85 I had, dunno bout yours.

Sent from my SCH-I535 using Tapatalk 2

[fatmobile]

 Make sure the sensor has a good ground.
 If not, the voltage will go high and trigger the light.
 If you can pull back the rubber boot and measure the voltage drop accross the sensor while the engine is running it will tell you what the sensor circuit is seeing.

[Vohaul]

mine doesnt have a rubber boot as far as i can tell...it has a hard plastic plug (with clips ) that goes into the top of the overflow tank

[fatmobile]

So the wires connect to a hard plastic plug that disconnects from the sensor connector?
 Can you stick a volt meter to the wire ends while it's plugged in?

[Vohaul]

So the wires connect to a hard plastic plug that disconnects from the sensor connector?
 Can you stick a volt meter to the wire ends while it's plugged in?

only if i strip a little insualtion off the wires going into the plug......ive been running it for 4 weeks now at 120km + a day with no issues.....one day the light flashes...next day it doesnt....temp guage is working and never goes above 1/2 way..and thats only if im in downtown traffic....which is normal...most days it doesnt go past 1/4

on start up , thje light is off...usually after about 15-30 seconds, itll start flashing...if it hasnt turned on by then, it wont turn on the whole drive....