Club 80-90 Forums

Hi

How does this work ?

Having replaced my diesel with a petrol engine....

I now have a new expansion tank which has the 2 pin probes that sit in the water, and a redundant LED yellow glow plug light on the instrument panel.

Im thinking.... if I put the live feed with in line yellow LED to one of the probes and and connect the other to earth - does a drop in coolant level below the probes make the circuit - and light up the led ?

I will get a battery, wires and glass of water out later today to tinker - just wondering if anyone knows if this how the probes work to activate a buzzer or warning light ?, or do they go through a micro relay to activate a warning signal.

Thanks

matt

Pretty sure the coolant below the level breaks the circuit, The coolant is conductive to some degree.

there is a 'relay' no 43 in position 3 that detects the change in resistance and with some wizardry it brings the high temp light on the dash without raising the gauge, low resistance pulses I think.

I say 'relay' because is isn't a relay but looks like one

matt brighton wrote:
Having replaced my diesel with a petrol engine....

excellent choice

itchyfeet wrote:there is a 'relay' no 43 in position 3 that detects the change in resistance and with some wizardry it brings the high temp light on the dash without raising the gauge, low resistance pulses I think.

I say 'relay' because is isn't a relay but looks like one

Thanks for the reply - I see how it works now

- I Buggered my temp gauge when deleting the constant red led blinking by shaving off the centre pick up on the back of temp guage ...

So.... Im getting some aftermarket gauges for oil pressure/ battery voltage / and water temp -

Would like to use the yellow diesel glow plug led as a low coolant warning - so I guess I will have to identify a sensitive solenoid that will ground the live to that, when the probe breaks the circuit.

Thanks again

Matt