Low Coolant Level Sensor

Bob, you need to check if there is any power coming from the connector. Try using a simple wire and bulb system, ensuring that the ignition is switched on. I cannot see MG putting a cable/connector in place with no bulb and ancillary.

Hi David,

Thanks for your suggestion.
Without wishing to appear too thick, are you suggesting I should:

Take two lengths of wire, then taking the plug end that is part of the wiring loom, put one piece in each of the connectors in the plug, attach the other end of the wires to a bulb, and switch on the ignition.

The bulb should then light, proving power is flowing along the wiring loom.

If I have got this wrong then perhaps you can give me an idiots guide on how to try out your suggestion.

Bob, take a 12v bulb and solder/connect a length of wire to the end of the bulb, this is the positive end of the bulb.

Connect another wire to the bulb casing. Now to test, place one end on the plus side of the battery, the other end on the neg side and the bulb will light.
Now, take the positive end of the wire and connect this to one side of the plug connector with the ignition on and see if the bulb lights. If not, try the other side. If the bulb does not light, then there is no power obviosly to the connector.

Thanks for that, I will give it a try.

My mistake when fitting the b&g system was to push the float down with a screwdriver -it didn't work because the driver was magnetic.
Use a piece of dowel or similar.

Bob, whereabouts in Essex are you? If it's not too far from Billericay, I could pop over with my multimeter and check it out with you...

Hi Bruce,
I'm in Chelmsford so that would be great.
I could drive down to you at a convenient time for you.
Cheers,
Bob

Bob, I've sent you a PM...

Hi David, and Bob, I am a new owner of an MG TF 135. My car is an 04 reg and after reading your posts with interest regarding the coolant level alarm and being very conscious of the problems I have bought on Friday a new coolant bottle with the sensor. I have had a look today and tested the wire that would connect to it and I do have 12v with the ignition on. I tested the switch on the level switch and this works with a multimeter. My low level light on the dash comes on when I turn the ignition on for a couple of seconds and then goes out. But when the bottle level switch is connected to the wire plug and simulated by turning the bottle upside down (obviously not fitted to the car as yet) no warning light comes on the dashboard to show low level. Any clues welcomed. Only thing I haven't done yet is to short out the plug with a bit of wire to prove it.

I'm sure you must have but...

Did you try it with the bottle the right way up? If it's a float valve, turning it upside down would simulate a full bottle, wouldn't it?

ERRR Yes you are quite right. I did try it both ways though, but thinking about it not that long the right way up. I will try that again tomorrow now. Thanks for showing me how thick I was Lol. Cheers Bruce.

:lol: