newRX-7

I will skip all the boring BS.

I have a somewhat inexpensive ohmmeter and im testing my thermo sensor. the old one reads as follows:
creeping up to 176 F it will do this
.415ohms
.410ohms
.405 ohms so on and so forth until at about .370 ish and then it jumps to 360.78 ohms
I bought a new therosensor and the same thing is happening (only difference is about + or - .04 ohms
PLEASE help me understand this thing. can it be the ohmmeter, or can it be two bad thermo sensors in a row?

Boosted11

iTrader: (11)

I have no answer for your question, but I have a question. Where do you get a water thermo sensor these days? I can't find any, unless im looking in the wrong sections on sites.

newRX-7

Oh i got mine from my local auto shop...Baxters. I assume you could get one from a napa or auto zone maybe.

AGreen

iTrader: (11)

Read the ohmmeter scale homie. It's probably starting in Kohms, then jumping to plain ol' ohms.

maybe...

newRX-7

that is a damn good idea homie, the meter is a friends and just some ol one he had in his garadge so ill check it out with him.

AGreen

iTrader: (11)

reason I said that is because you said ".405 ohms, so on and so forth until at about .370 ish and then it jumps to 360.78 ohms".

.370 Kohms is 370 ohms, then it goes straight to 360 ohms. Seems like that is probably the case.

HAILERS

Nah. Try doing it slightly differently. Put the meter on VOLTS DC instead of ohms. Leave the plugs on the ECU and backprobe the water thermo sensor wire with your meters positve lead. Negative lead on a known ground point.

Then start the engine and let it idle from cold til it gets fully hot. As the water temp rises, the volage slowly drops on the meter. When the engine gets fully hot the voltage will be approx 0.5vdc.

When you start out the voltage could be in the 1-3vdc range depending on how cold the weather/engine coolant is.

I wrote on a thread on this site a couple of weeks ago the Approx temp vs voltage. Somewhere.

HAILERS

Something like the attached jpg.

newRX-7

Thanks HAILERS, I will try it when i get this car running. currently i am having troubles that when it warms up and i have the idol set at a low 900-1000 the thing dies and i cant restart it when it it hot.