Exhaust Temp Gauge Question

[Graplr]

When I bought my 6.5 diesel a few years ago there was a Banks Boost/EGT gauge combo installed. The boost was hooked up and works. The EGT had a wire running to the engine bay but no probe installed (nor probe that came with the vehicle). So I did a bit of research and to me, it seemed like any Type K thermocouple should work. So I purchased one off eBay and installed the probe. The wire from the gauge had two ring terminals and the thermocouple wires (two total) were like plugs/pins. So I stripped the ring terminals to crimp together. Obviously something is hooked up incorrectly because the gauge doesn't work. As best as I can tell the gauge is just a mechanical type thermocouple. When I stripped the ring terminals the yellow wire was just a small wire but the red wire had a small wire plus a thicker almost ground looking wire inside but both went to the ring terminal.

So, any pointers on what I can do to get the gauge hooked up and work? I found the Banks website with install instructions but they just state connect wires to probe. No diagrams.

Thanks!

[jplinville]

Not Banks, but the idea is the same...I hope this works.

EGT, exhaust gas temperature gauge, Westach, Westberg exhaust gas temperature wiring diagram

[Air&Road]

Originally Posted by jplinville

Not Banks, but the idea is the same...I hope this works.

EGT, exhaust gas temperature gauge, Westach, Westberg exhaust gas temperature wiring diagram

That is the EGT stuff I'm used to seeing. It is the standard stuff used in aircraft. Lots of resources, like Aircraft Spruce and another company I think named something like Air Chief.

[Graplr]

Thanks guys. I went back out and revisited the wire connections since the diagram JP provided shows simply connecting the wires. What threw me was one of the wires had two inside of it.

I took off the crimps and simply twisted the wires together and it appeared to be working. I had just run some errands in it so the engine was warm. At idle I was showing 2k degrees and it did increase with applied throttle and RPMs. So I just made sure the wires were nicely twisted together and put electrical tape around the connections. The connections are in a nice place and out of the way. So perhaps it was just a bad crimp (the pins were much larger than the small wire or I just did a bad job).

We'll see how it works as tonight it is going on a fishing trip to Canada and then back next Monday.

[MS Fowler]

2000 degrees at idle?

Seems high to me. Where is the probe located--before or after the turbo?

[Simpler=Better]

Your calibration might be off a bit....aluminum melts at 1,200 degrees...

[MS Fowler]

Originally Posted by Simpler=Better

Your calibration might be off a bit....aluminum melts at 1,200 degrees...

That's what I thought. My friends on the Ford IDI forum used 1200 as a short term max if the probe is pre turbo. They never want to see that number after the turbo.

[kerry]

2k degrees Fahrenheit is way too hot. On my CAT 3208 pre-turbo I run around 900 degrees on the flat. If the gauge gets above 1300 degrees I start worrying. Limited air flow/enriched fuel will increase the temperatures substantially. At 2k you'll be melting your pistons in short order.

[Graplr]

Yes, sorry. I was just thinking that. It is 200 and rose to about 300F when I was watching it. The gauge shows single digits and of course one needs to multiply by 100, not 1000.

[aklim]

I don't know about your system but Autometer says that you are NOT to cut the wires.

[Air&Road]

EGT in my plane runse around 1200 degrees when leaned out properly.

When I was in college I worked in an electronic component burn in lab. We used thermocouples all over the place, mostly in ovens where components were tested under heat. Buying thermocouples was an expensive proposition. We made our own by simply tinning the iron and constantine wires separately and then twisted them together. It worked great.

That said, the highest temps we usually saw were 250 degrees Centigrade, so that might not work at EGT temperatures. In fact, I fully expect that solder melts below EGT temps. BTW, the reason for tinning the wires was to slow down the oxidation of the individual conductors.

[Graplr]

Originally Posted by aklim

I don't know about your system but Autometer says that you are NOT to cut the wires.

Probably not but with this gauge I don't have much of a choice as no sender came with it and it had ring terminals on the end. So either buy a new gauge or make this one work. We'll see how it goes. Also the instructions from JP's link say one can lengthen the wire by 15".

[Angel]

Thermocouple wire length should not make a big difference- a good connection is wayy more important (thermocouples generate a millivolt signal proportional to temperature.
At my power plant, we have lots of them that are over 100' away from the 'meter'- I'm surprised that the manuf. would say that.

Thermocouple - Wikipedia, the free encyclopedia

a type K has enough range for an EGT. But 200F seems kinda low for exhaust temps on a machine that has run for more than 5 minutes.

You need to connect the red wire and the yellow wire to the meter- if it seems off or doesnt read at all try reversing the polarity.

The 'bare' wire is probably a ground or earth. First, try it with the bare wire disconnected, then if the reading is still off, land the bare wire on a grounding screw on the meter and see if that makes it more realistic. I'd expect numbers like you see posted here for EGT's (800-1200F). Its possible that they expect either the red lead or the yellow lead to be grounded (depends on the meter) but I'd try it ungrounded first.

They dont want you cutting the wires becuase it potentially makes a "cold junction" - I wouldn't worry about that, just make sure that the connections are as clean as possible (crimps vary a lot, I like screw terminals (look at Radio shack for a "Barrier Strip") or soldered connections.

(and yes, I am an Electrical Engineer, but that doesn't mean I know how to actually wire things together, ask any Electrician

-John