Wiring issue's, Can someone tell me if the temp wire is hot?

[Speedy94c]

Ive got a 85 monte SS that Im about to get on the road (this weekend I hope) It has stock gauges, so I got the correct sensors for them. The car had some of the wires cut in the harness. I think the solid green wire goes to the temp sensor but it has low voltage on it when I test it with a test light. The light comes on but it is not real bright like if I hit it with a constant 12v. Is this the correct wire? I have a regal and it is the solid green wire to the temp sensor but I have never checked to see if it has constant power to it. The regal don't have a motor in it now so I cant check that at this time.

thx in advance

 

[pontiacgp]

The temp guage is an ohm reader.. The sender sends out ohms according to the temperature of the coolant. If you take that green wire and ground it the temp guage should be pegged on the hot side if it is the temperature wire

 

[Mike buttafuoco]

I am not sure about the color. If I get some time later I will Fire up my alldata and take a look and see if I can find a diagram. As far as being a "hot wire", that is incorrect as the sensor provides resistance to ground and that corresponds with your gauge. You may see the presence of voltage as it has to go somewhere and the low voltage would indicate that your gauge has internal resistance. Ground the wire and watch your gauge as it should peg either way, full hot or full cold. Depending if it is positive temperature coefficient or negative temp coefficient. I am almost 100% positive that the gauge wiring is always a ground if it is one wire. As I mentioned before, ground the wire and see if that gauge responds or any gauge for that matter. Keep me posted as I would love to help. My tail is wagging.

 

[Mike buttafuoco]

Now that I think of it, the green wire is temp and the blue wire should be oil pressure. Any body???

 

[pontiacgp]

The temp wire is green but I believe the a/c fast idle solenoid on the carb is also green.

 

[Speedy94c]

The temp guage is an ohm reader.. The sender sends out ohms according to the temperature of the coolant. If you take that green wire and ground it the temp guage should be pegged on the hot side if it is the temperature wire

Yep that was it. I did what you said it my temp gauge was all thw way over past hot. thx

 

[Speedy94c]

I am not sure about the color. If I get some time later I will Fire up my alldata and take a look and see if I can find a diagram. As far as being a "hot wire", that is incorrect as the sensor provides resistance to ground and that corresponds with your gauge. You may see the presence of voltage as it has to go somewhere and the low voltage would indicate that your gauge has internal resistance. Ground the wire and watch your gauge as it should peg either way, full hot or full cold. Depending if it is positive temperature coefficient or negative temp coefficient. I am almost 100% positive that the gauge wiring is always a ground if it is one wire. As I mentioned before, ground the wire and see if that gauge responds or any gauge for that matter. Keep me posted as I would love to help. My tail is wagging.

Yes that was it. I did ground it out and it sent the gauge to full hot.

 

[Mike buttafuoco]

Yes that was it. I did ground it out and it sent the gauge to full hot.

Sweet brother! Also want to mention in the future: if you didn't already know this(I apologize if you do) but test lights just show presence of voltage not actual voltage. I have a power probe and a couple different multi meters(I was in the business) and those tools are invaluable for trouble shooting Electrical circuitry. I rarely use a test light and have used it sparingly over the last 10 years. A power probe is the cats a**!

 

[Speedy94c]

Sweet brother! Also want to mention in the future: if you didn't already know this(I apologize if you do) but test lights just show presence of voltage not actual voltage. I have a power probe and a couple different multi meters(I was in the business) and those tools are invaluable for trouble shooting Electrical circuitry. I rarely use a test light and have used it sparingly over the last 10 years. A power probe is the cats a**!

There were 4 wires that didnt have ends on them for the guy I bought my car from was going to do a LS swap into it so he had cut them.
I was just testing them to see if any were hot. There were 2 brown wires, dark green, and a green with a white stripe. The two brown ones were full hot and the green one just barely lit the light, and the green with the white stripe has no power. I have been wanting to get me a power probe just for testing
this kind of stuff, I will check into one for sure.
thx again Steve

 

[Mike buttafuoco]

There were 4 wires that didnt have ends on them for the guy I bought my car from was going to do a LS swap into it so he had cut them.
I was just testing them to see if any were hot. There were 2 brown wires, dark green, and a green with a white stripe. The two brown ones were full hot and the green one just barely lit the light, and the green with the white stripe has no power. I have been wanting to get me a power probe just for testing
this kind of stuff, I will check into one for sure.
thx again Steve

ANYTIME! I love helping out fellow motorheads!