Thread: Water Temp Gauge signal Question

Just a quick Question,

Im installing a Digital Water Temperature gauge into my car. I dont really want to cut the radiator hose and install an aftermarket Temp Sender unit if i can help it, they are ugly and just cause one more potential leak.

Can I splice into the factory temp sender wiring? I want to retain the factory Temp gauge too, is this possible with this method?

Cheers!

you can mount it into the bleed bolt but i believe you need to tap it out. i did this on my d series, measures the temp of the water coming out of the engine into the radiator

Im not planning on fitting a new sensor(hopefully ), i want to just take my signal off the wires from the factory Temp sensor

im pretty sure it doesnt work. but i may be wrong.

see shiftyjonnos post

I suppose to test it i could take the sensor out of the car, hook it up to the gauge and then put the gauge accross the battery and see what it reads, then dip the sensor in boiling water for a while and retest. If the gauge reading increases then it should work fine.

Possibly......

Originally Posted by shiftyjonno

Or you could just test it while its in the car ...

Wires arent long enough and i have a motor sitting in the garage i can quickly pull it out of. Easier this way

Originally Posted by shiftyjonno

It depends on whether you aftermarket unit bases it's readings off ...

The Honda water temp sensors use resistance as the way to calculate the coolant temp. The higher the temperature, the less resistance.

Your aftermarket sensor might work the opposite way (higher temperature = high resistance) in which case they are not compatible.

I have one of the horrible install-it-in-the-radiator-hose type sensors, and it is not compatible with the factory sensor.

It will also depend on what the resistance span of the sensors are, as to whether it will give you a meaningful result.