Attention Gearheads and Wirenuts... Need some help with this one.

nctom

nctom

Well-Known Member
Joined
Dec 9, 2008
Location
CONCORD NC
I was gifted a neat little digital dash cluster of gauges out of an older trophy truck. Very much like a racepac display. The company was small and made custom F1, Indycar stuff. They went under a couple years ago. I have all the readings working well, but this little jewel was in the box with the rest of the stuff. (Not missing any hook ups on the elect. panel)

I am trying to figure out what da' heck it is. It may not even go with this unit, but I may want to use it for launching a missile or something.

It is a small sending unit looking deal with 3 wires. Red, Green and Black. The black wire is short and terminated for a ground wire screw. If you ground the black and put power on either of the other 2 wires, 12 volts pass right through it. (Have not put a ohm meter on it while rasing the temp, yet). It isnt a o2 sender. Definatly a temp sender, but the elect. temp. units that I am familiar with have 1 hot wire and ground via the block . Maybe with a warning light feature? Hmmmm... o_O So what the heck is this thing?


rrimage.jpg
 
resistance temperature sensors are more accurate than on/off temperature sensors. There are a lot used in oem vehicles...especially newer ones. Works the same way as a 4-wire o2 sensor.
 
Can you explain a little more? My understanding is that all electrical temp senders work off resistance. Why two wires instead of one? I was thinking maybe 1 for the gauge reading and 1 for a hot warning light? IDK.
The new LS Chevys have multiple wires on the temp sender, but that is so they can feed the PCM and a gauge off the same modular sender. I would not think that is the case here, but I could be wrong. Remember that I am 45 so some of the newer stuff has gotten by me!:D My wife is on a baking binge, so I cant get into the kitchen to drop it in a pot of water with my multimeter hooked up.
 
I'm not really sure myself, but in layman's terms the one and two wire sensors tell the ECM "yes, your engine is at operating temp." or "no, stay in open loop mode". The three wire sensors say exactly how warm. There is a wire winding inside that metal part on the end.
 
It's a flange rod acute angle thermanglactic probe-a-zoid which reports to the DAU (data acquistion unit). Uncommon 2 wire model, most have 147 leads on them.
 
It could also be an electric fan switch for a two speed electric fan. Some nissans and fords ran radiator fan switches like that.
 
Looks to be an impedence probe RTD style temp sender.
In simple terms as the temperature changes the impedance fluctuats along a defined plane this allows a true temp guage as opposed to an older resistance switch 2 wire deal where it was either open or closed and triggered a light.
 
Back
Top