Recently the oil pressure light on my L295DT began coming on at odd times. I purchased it used from my neighbor a few months ago and before that I borrowed it often, so I'm familiar with running it. It has many thousands of hours on it-not sure exactly how many because the meter quit at 7000 some years ago. In any event other than some leaks and a rear tire that needs replacing it is a solid machine. Sometimes the oil pressure light would come on at low idle and I would just bump the throttle and it would turn off immediately. Now it seems to come on at random, high RPM, low RPM, cold, hot, etc...no rhyme or reason which has me hoping that its a bad sensor or bad wiring, but I'd like to attach an oil pressure gauge to be sure. No weird noises or excessive knocking so far though. Any suggestions on a specific gauge? I'm assuming I can just plug one into the port for the sending unit? Hole size? Thread?