temp sensor

[mccabe]

so i just got a new mx3 and the temp gauge dont work but i know the sensor does cause my fan still work properly and the gauge sometime wokrs, but i have an after market gauge and i need to conect it to the sensor witch one and were do i connect it too?

[Nd4SpdSe]

Fan and temp gauge use 2 different sensors...that being the case, if it's the sensor, your aftermarket gauge won't work either.

[Mi|<E]

What kind of gauge?

Your thermosensor is number 8 on this

http://www.mx-3.com/manuals/showimg.php ... E2-002.gif

And your single wire temp gauge sensor is in the lowest picture on this one:

http://www.mx-3.com/manuals/showimg.php ... E2-005.gif

if its the kind of gauge I think it is run the signal wire off the sensor ( it acts like a potentiometer but with
heat as the variance ) and ground to a good chasis spot.

[mccabe]

i not sure the brand there cheep tho im pretty sure princes auto but it has a ground,acc,constat,and a green wire and is called the signal wire. the diagram says im supose to connect it to the + wire for the temp sensor

[Newfie_dan]

yeah thats the wire that connects to the top of the single wire coolant temp sensor. Just so you know the oil pressure one from princess auto will not work on our cars as we have an oil pressure switch and not an actual oil pressure sensor. The switch is not variable its on/off only whereas the sensor is variable resistance.

[mccabe]

yeah i got the temp and volt gauges

[davmac]

What kind of gauge?

Your thermosensor is number 8 on this

http://www.mx-3.com/manuals/showimg.php ... E2-002.gif

Just to clear some things up here: Thermosensor #8 in the referenced manual is a 2 wire GREEN temp sensor that is used as input to the ECU to control idle.
There is a SINGLE WIRE temperature sending unit just to the right (when looking at the front of the engine from passenger wheel) that sends a signal to the dash gauge.
Finally on the K8 and used by early klde ecus there is a GREY 2 wire thermosensor on the right side of the coolant neck (other side of the cap) that sends coolant temp to the ecu to turn on the rad fan.

And your single wire temp gauge sensor is in the lowest picture on this one:

http://www.mx-3.com/manuals/showimg.php ... E2-005.gif

if its the kind of gauge I think it is run the signal wire off the sensor ( it acts like a potentiometer but with
heat as the variance ) and ground to a good chasis spot.

The sensor shown on this page of the service manual is actually the oil pressure sender.

[Newfie_dan]

I have to correct you on that last statement davmac its not an oil pressure sender, its an oil pressure switch, you need to see a certain oil pressure to open/close the contacts inside, whereas an oil pressure sender sends a variable resistance or voltage read by the gauge or ecm to determine oil pressure. Both coolant sensore for the v6 are behind the rad cap on the filler neck passenger side of the engine bay, 1 2 wire as davmac said and the other is a single wire for the dash.

[Mi|<E]

Thats what I get for posting late at night

Yeah pic 2 is the oil pressure switch, my bad. It does not
throw a light on unless it drops below something crazy
like 4 psi.

[davmac]

Yea you're right Newfie_dan it is a switch. So you can't simply hook a wire to that unit and to an aftermarket gauge. You can drain oil and unscrew the pressure switch and replace it with a variable sender and run that wire to an aftermarket gauge. Generically speaking it does send an oil pressure signal back to the dash for display - but just a light to let you know: engine will soon be toast.

[Newfie_dan]

yeah I am working on modifying my oil pressure setup to accomodate a variable oil pressure sensor as soon as I can get the cash and time for it. I am going to use a T fitting to add a variable sensor along with the regular 1.

[Nd4SpdSe]

yeah I am working on modifying my oil pressure setup to accomodate a variable oil pressure sensor as soon as I can get the cash and time for it. I am going to use a T fitting to add a variable sensor along with the regular 1.

That's exactly what I did on my truck a few weeks ago actually. The hard part was finding adapter fittings since the aftermarket sending unit uses an standard NPT thread, but the truck uses a metric BPST thread.

[Newfie_dan]

yeah I was aware of that, I am a heavy equipment tech and if need be I can make my own T adapter for it by modifying a standard metric bpst threaded T.