I put a new thermocoupler on pre-turbo. The old one was not reading all the time and was post-turbo so I ordered a new one hooked it up and got no reading, so I took it off and hooked up the old one and it works, did I get a bad coupler or did I order the wrong one. thanks for your help

 

Do you have a digital multimeter (Fluke or similar)??

 

yes I have a fluke

 

I looked at the web site that I bought it from, I think what happened was I ordered the high temp probe by accident it has two choices high and low temp one is rated at 0-2000 and the other is 0-1600, well when I used the scroll wheel on the mouse to scroll down the page it changed to the high temp probe, do you think this could be my problem??

 

I think so.
Mike

 

no, thats not it. The high temp one will still work fine.

Measure continuity (ohms) between the two sides of the probe. make sure its not open (reading 0)

 

I am at work now so I will have to check when I get home.

Are you sure the high temp will work, I hope so because the site said NO returns on installed exhaust stuff. That would be crappy

 

53 ******,

If one probe has a 0-1600 range and the other has a 0-2000 range, why would it not work??

A thermocouple is simply two different wires welded together. By heating the wires it produces a very small millivoltage which is measured, amplified and displayed on the guage. The high temperature version just has one different wire and the tip is different & made from Inconel (I believe).

As long as you didnt cut the wire and the continuity is good, the thermocouple should work.

As a last resort you could always call Isspro (technical department) and make sure the thermocouple you ordered will work with your guage. Just my 2 cents.

 

Yeah I get what your saying, I thought that the gauge/amplifier might be calibrated to a certin thermocoupler but who know's, I will check the OHMS in the morn and let you know what I find.
Thanks for your help DR. EVIL

 

you can heat up the thermocoupler with a flame and check the milivolts.. I believe most put out around 75 milivolts when hot...

 

Yeah, that would work as well....check to make sure the mV's change when heated slightly. Watch close because they probably wont change a whole lot.

 

no...according to J type thermocouple tables....75 mV is over 2000F

BUT, I cant really say for sure since I dont know the exact specs of the Isspro T/C

 

I don't know the exact milivolts either.. I deal with them in the natural gas industry and know those runs around 75 milivolts or so.

If he was to heat it up and gets any reading then then problem is not the t-couple. I would also check that the 2 leade of the t-couple are not touching at the 2 little screws or that the wires have not chaffed and are touching in the wires to the amplifier box.. If the wire short against each other you won't get a reading.

 

oops also check for one of the lead wire grounding out against the body of the truck

 

I will double check the wiring but I checked it before I ordered the new one.
The old one would bounce on and off when I played with the wires coming out of the probe and the ceramic was broke out at the top, so I thought it was that for sure I will check the new probe with the Fluke in the morn and see for sure.