JDubya

Ok, I've asked this before on here, and I've IMed people selling a Greddy EGT gauge to check, but no one has helped. I need help with a wire, which is pos...?

The wire I'm talking about is this, the EGT Probe is connected to a braided wire and on the end of that wire it has a ceramic coupler. Then another braided wire gets attached to that coupler. This is the one i'm talking about. The one were you unscrew that little screw on top of the ceramic piece to put the wires in. I need to know which one is positive, and neg. There is an orange wire, and a white one. Could someone please check which is which for me? Thanks.




Modified by ALL MOTOR LS at 8:12 PM 2/8/2004

keebler65

the org, white, and red wires are all positive. one is backlight, constant power, and switched power but i forget which is which. the black is ground. is this what you're referring to?

JDubya

No no, I'm not talking about the power wires. Re-read my second paragraph, I'm talking about the wires connected to the EGT Probe.

JDubya

Bump so i can be boosted soon...

TrueNorthStar

When it comes to TC's Red is allways neg. If I were to guess I would say your orange wire is neg and the white is pos. If you have a volt meter you can test the leads for a mv.

JDubya

I cant find my VM But when I do, how would I go about testing this. Does the gauge have to be hooked up to power, or can I just hook the sensor wires up and test them?

and if you have this gauge, can you check what yours is?

JDubya

Still can't find my VM. Anyone out there kind enough to check?

TrueNorthStar

I have a type-k tc in front of me and with my vm on it reads 0.1mv@room temp (70f) When I pinch it between my fingers I get about 0.4-0.5mv and when I put my lighter to it I get 39.1mv.

My wires are red and yellow, yellow is + and red is -.

Hope this helps.

EDIT:

You just hook your vm to the sensor directly, no power needed.

TC's work on the principle of 2 different metals generation a voltage (how ever small) when they are joined together. When the temp changes so does the voltage that the Tc will generate.

JDubya

Yea, I know the polarity of the sensor. I just need to know which wire coming from the actual gauge is positive of negative. like the sensor is connected to wires then they connect to that ceramic piece. Then the wires coming from the gauge get hooked up to the ceramice piece, those are the ones I'm talking about. Thanks for checkin tho.

JDubya

So who's not watching the Super Bowl? I doubt I am....


ehh, maybe for the comercials

keebler65

edit: i see its not a thermistor....

if you're looking for the polarity of the connector on the gauge, have you tried using an ohm meter going from the ground of the power harness and then the other probe at the sensor harness, one wire at a time. depending on how its wired internally, theres a chance that one of the wires will read zero ohms, in which case that would be your negative wire for the sensor.

JDubya

Yea i'll try that if i can ever find my damn volt meter. I'm not gonna buy another yet, b/c you know the day i do will be the day i find my old one.

keebler65

i forgot to mention, also if you cannot find zero ohms on either terminal, then reverse it: probe from the positive part of the power harness (you might have to hook all the positive wires together just to be safe) and then probe the two sensor terminals. if zero ohms there, then you know thats the positive. its hard to say which way it is, but i would think one of these two methods should work.

good luck

JDubya

pic added

JDubya

One last bump...

TrueNorthStar

Looking at your pic, the white wire is the + going to the ceramic connector the red is -

JDubya

are you sure, or just guessing?

TrueNorthStar

I'm 99% sure. With the TC it won't hurt the system if you hook it up backwards. It would just read a - number. The TC will generate is own -signal if it is cold enough.

Remember, TC work in MV, which is very very low voltage, There is no voltage being sent to the probe, it is created by the probe. Your guage just reads the voltage you are getting from the probe.

Oh BTW I work with TC's and RTD's all day long.

JDubya

OK, thanks a lot. Finally, an answer

TrueNorthStar

np, glad I could help.

G-money

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ALL MOTOR LS &raquo;</TD></TR><TR><TD CLASS="quote">Ok, I've asked this before on here, and I've IMed people selling a Greddy EGT gauge to check, but no one has helped. I need help with a wire, which is pos...?

The wire I'm talking about is this, the EGT Probe is connected to a braided wire and on the end of that wire it has a ceramic coupler. Then another braided wire gets attached to that coupler. This is the one i'm talking about. The one were you unscrew that little screw on top of the ceramic piece to put the wires in. I need to know which one is positive, and neg. There is an orange wire, and a white one. Could someone please check which is which for me? Thanks.




Modified by ALL MOTOR LS at 8:12 PM 2/8/2004</TD></TR></TABLE>

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