And so the saga of the temp gauge continues. I bought a potentiometer yesterday, gonna try finding the correct resistance for the supra sensor.

 

But the GE sensor should work, shouldn't it?? anyway, when using a potentiometer, you basically put it in the temp sender wire, right? Then dial in until the temp gage reads correctly? Once you find that value, try creating that resistance with a series of resistors (you know a resistor of the exact value won't exist

let me know what you find out. Too bad some of the SC300TT fellas that have working temp gages won't tell how they did it

 

Its weird, some people have no problems wiring in the 330 ohm resistor, but some do. And yeah, thats how the potentiometer works, kinda like dialing in the correct resistance while someone watches the gauge.

 

what's your number so I can call you We gotta get this thing figured out

 

SUCCESS!!! Here's what happened to me. I installed the GE sender unit which seemed to work fine until the car started to warm up. Then the temp gage went straight to HOT. The reason why is because I wrapped the heck out of the sending unit with teflon tape, then I added some blue silicone to that. I did this being overly cautious of a leak considering I'd tapped this new location.

The problem with having wrapped it so heavily in teflon and then adding silicon is that the unit wasn't grounding properly. This is a one-wire sensor that gets ground from being threaded into the water neck. Well... I had hardly any grounding. I thought the sensor wouldn't work at all without grounding, turns out it works but produces the wrong signal (doesn't really make sense to me).

Anyway, I tested this without unscrewing the sensor by strapping some wire from the sensor hex-head to the water neck. When that gave me the right reading, I did something you'd consider lazy I soldered the wire from the sensor to the water neck I did this because my sensor doesn't leak water and I want to keep it that way.

Also played some more with the stock supra sensor and finally found that 290ohms gives the right reading on the gage (for me, anyway). I had to get this using a 10, 100, and 180 resistor in-line.



Hope this helps someone.

 

Yeah, that would be me I'm gonna try and get that combination of resistors tommorrow and test it out. Thanks bro.

 

Found out today that rather than modifying the water neck to accomodate the GE sensor (16x1.5mm), the GE sensor will fit into the stock SC radiator. Say that the radiator is still mounted in the car, fan shroud removed. Looking down the driver's side of the radiator you have the drain plug to the far right. To the left of that is another plug. I think a sensor belongs here where this radiator is used on another car. I unscrewed that plug and tried the GE sensor there. The GE sensor fits perfectly.

I'm doing all of this because my modified water neck finally sprung a very, very small leak. So I've installed an unmodified water neck with the two original sensors mounted. Only the temp sensor is connected, the sender unit is there as a plug only. I've extended the sender unit wire to connect to the GE sender that i screwed into my radiator. I also used this as opportunity to install my TRD Japan 160 degree thermostat.

I'll let everyone know how this turns out.

 

a little OT but does anyone know if there are any negative affects using the stock sc radiator instead of the TT supra?

 

Well, i installed the GE sensor in the GTE water neck and low and behold its still pegged on hot! I wired a 270 ohm resistor inline afterwards and it pegged on cold. Somehow there is resisitance within the harness itself. I could have just used the stock TT sensor. This is such a pita.

 

I haven't had any problem. My friend bought ethan's 915rwhp SC which also uses the stock radiator without an issue.

I DID, however, install a TRD Japan 160 degree thermostat (recently) and a TRD 1.3bar (18psi) radiator cap for peace of mind.

 

with the resistor inline, the car will show cold if you're just idling. You have to start driving the car before the temp gage actually starts to move.

 

I broke down and bought an aftermarket gauge.

 

Where did you mount it?

 

I got one with a block that goes in the actual hose. It'll probably read more accurate anyways.

 

I meant where in the car (interior) did you mount it