Ice Warning Sensor Repair

[brogenville]

The ice warning light- not the most essential aspect of the car, but on my cerb it doesn't work, so like any good owner I want to fix it. Whilst I have heard of other people with ice warning lamps that are also faulty, I've had a search through past threads and I've come up with no info on what is lickely to have gone wrong.

So, does anyone have any clues as to what is a common fault with the sensor system? Failing that, does anyone know where to locate the sensor itself?

Lastly, I cant rule out the possibility that the bulb(s) itself in the dash has gone. With this in mind, can anyone who has a working sensor let me know if the bulb is supposed to light up when you start the car just to show its operational?

Thanks in advance, Rob.

[mikesr]

Its is in the centre of the wiring harness that sits infront of the radiator and air con condenser. (At least it is on my 98 4.2)
The harness is tie wrapped to the body work.
If you remove the reg plate reach in through the front its on the harness behind the horns. Far easier access would be to take the bonnet off and the air scoop out.

Its a 2 pin plug and socket wherein the plug just has a loop of heat shrink protecting the thermistor that connects to the two pins. Its most likely to be a very corroded connector.

[brogenville]

Thanks Mike- found it. Actually, the terminals looked perfect, and upon testing the thermistor output with a meter, it too seems to be working well.

So, working back, I guess the next place to check is the heater control box to see if everything is plugged in ok there.

[Tanguero]

brogenville said:

The ice warning light- not the most essential aspect of the car, but on my cerb it doesn't work, so like any good owner I want to fix it. Whilst I have heard of other people with ice warning lamps that are also faulty, I've had a search through past threads and I've come up with no info on what is lickely to have gone wrong.

So, does anyone have any clues as to what is a common fault with the sensor system? Failing that, does anyone know where to locate the sensor itself?

Lastly, I cant rule out the possibility that the bulb(s) itself in the dash has gone. With this in mind, can anyone who has a working sensor let me know if the bulb is supposed to light up when you start the car just to show its operational?

Thanks in advance, Rob.

The bulb in the dash is infact a bi-colour LED so it is less liekey to have gone. I don't I am afraid, recall whether it lights up with iginition - though I dont think so.

[Shootingbiker]

Taken from a Owners Handbook.

Upon switching on the ignition, the ice detector will go through a series of tests.
The warning light will illuminate green, orange and then red, after which the light will extinguish.
In use the light will illuminate green if the air temp is 5C or less, orange if 2C or less and red if the air temp is 0C or less.
If the red light stays on but temp is obviouly high then there is a fault.

Steve

[brogenville]

Hmmmmmm.... Thanks for that info. I suppose I need to check all of the connections between the heater control box and the light in the dash. Ah well, guess if I want to fix it...

[JensenA]

My Ice warning light works perfectly, but it doesnt go through that elaborate sequence of colour changing lights when the ignition is switched on, it just gives one brief red flash.
If you remove the top instrument cover, and unscrew the plate that holds all the instruments, you'll find a 4 core narrow ribbon cable coming from the small PCB at the top, this connects to another very small PCB at the bottom of the dash that connects to the 2 LED's for the main beam and Ice warning. This cable may be loose or disconnected. worth looking at just in case.