I'm lazy too, but in this case, like you said that darn thing is a royal PITA to get to so I thought I'd ask here first. Do you have pic of it? I'm wondering if I have enough room in it's hole for a different sensor. Since I'm changing a bunch of stuff to digital in the cab.
This is the sensor I'm considering -
thermistor sensor.
I'm actually working on an vehicle vitals panel so that everything that we need to look at is literally within inches of our line of sight. Personally it drives me nuts that I have to take my eyes off the road for more than a split second to check gauges while driving my truck, just because a lot can happen within that 3 seconds that I use to look down at the gauges, double check temps/air pressure/oil pressure etc and then look back up at the road. I guess, truth be told, it's not so much the time that concerns me, but more the fact that you don't see hardly any of the road while looking that far down, whereas in a regular truck/car you barely have to look down at all to check speed/etc and you can still see the road in the periphery or "subconscious driving" part, whatever you want to call it. I'm planning on putting the stuff I want to add above the "line of sight" right next to the air powered wiper motors, plus it'll all be above the "water-line" if I ever decide to take this beast fording.
It all started with the GPS speedo I'm making for the truck since I changed tire sizes, and will change likely again. Since I was already building that I figured that I might as well go for broke and put everything up there since I'm putting a few other things there as well. Water/meth controller and propane controller right now, but many others are in the works. And no, I'm not removing or modifying the OEM speedo. I'm simply adding another set of gauges.