Pyrometer trouble

[fulltimer]

My pyrometer has started acting funny. The
temps will swing wildly 2-300 degrees at
a time. What kind of test can I do to
isolate the trouble to the thermocouple
or the gauge? If it is the gauge I would
like to upgrade it to something better.
I have the RM Products brand with the very
dim lighting. Any sugestions on that subject
would be appreciated.



------------------
95 2500 4X4 Auto TST 230,
K&N Filter,PacBrake,4" Cat Back,
EGT-Boost-transmission temp gauges.
140K+ miles. 36. 5' Avion 5th whl

 

[illflem]

Sounds like you have a poor electrical connection somewhere. Check them all, beware that sometimes crimp connecters will look fine but are corroded inside causing a bad connection, I prefer to solder them for this reason. I've been told that the T-couples rarely fail, it is almost always the gauge.

 

[Ethdee]

I've seen many thermocouples fail. Every one has simply burned out; I've never seen one get flaky.

I'm with illflem; look for a loose connection, or perhaps a broken wire that touches 99% of the time. Look for pinches or sharp bends in the cable. Wiggle the wire and have someone watch the gauge.

Good luck!

Jim

 

[ProvenPerformance]

I work with thermocouples every day at work on high performance V-2 engines/data acquisition systems. Things to look for are: Make sure the red and yellow wires coming from the thermocouple itself (inside the shielding) aren't touching each other AT ALL... this can typically happen at the wire connections; Make sure that either wire (again, inside of the shielding) isn't rubbing anywhere and coming in contact with ground; Whether you are using a thermocouple connector or just screwing the wires into your guage, make sure your connections are clean and free of any/all debris. Thermocouples are extremely sensitive,but are quite durable, in general. Check things over and let me know if you need any other tips.

------------------
1995 4X4 2500, Reg Cab, Auto 3. 54, 90,000 miles, K&N filter, Autometer guages in tripple guage pod, Bosch plate, HS Idle screw bottomed;
1993 HD XL, 125ci (2050cc) S&S Long Block, 4 3/8" X 4 1/8", . 725" lift cams, 12. 8:1 CR, S&S Super "D" carb w/stack, Bassani exhaust, Modified frame and 3" over swingarm

 

[John_P]

fulltimer:

I had a similar problem with my pyrometer
about three months ago. My problem was
traced to the pyrometer tip being heavily
worn out due to all the heat. I replaced
the tip and it works real good again!

Hope this helps you!

-------
John_P

------------------
Red '96 4x4 2500 Auto 3. 54, TST #5, Major Pump Mods(By "Scheid Diesel") 370 Diamond B Injectors, Gov. Spring kit, AFC Spring kit, Banks Exhaust, Prime Loc, Cummins Chrome Kit,Psychotty Air Filter, Pro-Torque Converter, BD Valve Body, BD Pressure Loc, Isspro Gauges, Sendel 16" Alum Wheels w/ 33" BFGs

 

[fulltimer]

Thanks for all the replies. I will check
the wires and connectors. I had seen another
post a long time back about checking the
resistance reading from the thermocouple
and what temps these would relate to on the
gauge. Any comments on that?

------------------
95 2500 4X4 Auto TST 230,
K&N Filter,PacBrake,4" Cat Back,
EGT-Boost-transmission temp gauges.
140K+ miles. 36. 5' Avion 5th whl

 

[ProvenPerformance]

I work with thermocouples every day at work on high performance V-2 engines/data acquisition systems. Things to look for are: Make sure the red and yellow wires coming from the thermocouple itself (inside the shielding) aren't touching each other AT ALL... this can typically happen at the wire connections; Make sure that either wire (again, inside of the shielding) isn't rubbing anywhere and coming in contact with ground; Whether you are using a thermocouple connector or just screwing the wires into your guage, make sure your connections are clean and free of any/all debris. Thermocouples are extremely sensitive,but are quite durable, in general. Check things over and let me know if you need any other tips.

------------------
1995 4X4 2500, Reg Cab, Auto 3. 54, 90,000 miles, K&N filter, Autometer guages in tripple guage pod, Bosch plate, HS Idle screw bottomed;
1993 HD XL, 125ci (2050cc) S&S Long Block, 4 3/8" X 4 1/8", . 725" lift cams, 12. 8:1 CR, S&S Super "D" carb w/stack, Bassani exhaust, Modified frame and 3" over swingarm