Thread: Egt fitting

Originally Posted by turps

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I know changing the length of the probe wire is bad.
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Why

Originally Posted by biggin

Why

Because the instructions say so. It says that the join must be in the cab and something else. It effects the readings one how.

I am just not sure if i am meant to just connect the ends of the probe wire to the ems loom wires with solder or crimp connectors. Or does it attach direct to the gauge, which I don't think the probe wires are long enough to reach inside.

My others question is. How hot is the lead. As I was going to run it in the same split condut that I ran for the temp sender.

Originally Posted by turps

Because the instructions say so. It says that the join must be in the cab and something else. It effects the readings one how.
.............

How?
I'm not trying to be a smart alec, I genuinely want to know.

Hi,

I'm no expert but I think the length is important because the instrument (pyrometer?) works on changes in resistance / impedance. If you change the length of the whole system then you change the base level of this reading offsetting it. i.e. it is supplied with an excitation voltage / current on one wire and changes in temp at the sender are attributed to any difference in the value returned by the second wire. That I think is why the cable is shielded - to stop any induced effects. Put Pyrometer into google for a better answer.

I did this a while back. I forget how so I'll pop in the garage and have a look. I would have just crimped / spliced to the wires from the connector on the back of the EMS (I can't / don't solder).

Yes, the cable on the EGT probe I joined just past the bulkhead to the loom attached to the ems unit (only cm's away) so keeping to as near supplied length as possible, and as you say joined out of the engine bay drivers side of the bulkhead.

The cable on the pyrometer was easily long enough (for TD5 defender installed in the exhaust manifold just before the turbo) may be tight if using the blanking plate method though. I have quite a lot of it wrapped in a coil and tied up in the engine bay.

The lead does not get hot, but yes it needs to be of a fixed length as supplied.
Are you using the EMS extended wiring harness / loom for the install? This made my job a lot easier.

The guy who would probably know the most would be a guy on here 'the entertainer' I think, he runs NATA enterprises who distribute / sell this product in Aus.

Not wanting to to teach you to suck eggs but another important factor is exactly where you put the probe but there has been lots of discussion about that on here previously. Have a search lots of info on this install.

Once in they are good, just don't crash while looking at all the info and don't be too hard on yourself when you realise you may previously have been thrashing the engine a bit with the EG temps.

BTW is it a defender? If so where are you mounting the instrument? You can shuffle gauges about and get a really good finish at the end for a little more work.

Good luck.

Ian.

Hi turps,

With my VDO EGT gauge kit i found that the wires attached to the probe are stainless steel and likewise no advice in the instructions on how to connect to the copper gauge wires. So i crimped boot lace terminals (aka ferules) to the SS probe wires and the gauge wires as well (if you have a technician mate he'll have them). To join the probe and gauge wires together i ratted two brass barrel screw connectors out of a common 240V white terminal block (you buy them in strips at Jaycar etc) and the ferules mate with the screw connectors perfectly and are absolutely secure. This way the finished connections can be tucked neatly inside corrugated conduit to keep the wiring tidy but obviously the connectors need to be insulated from each other - you could just use an intact 240V white terminal block pair and tape with electrical tape for protection. Also consider mini spade connectors ....

onebob