Hey guys, I'm the newbie with an issue. I've got a 97 Cat 515 skidder and after about 20 minutes of running it starts giving me a trouble alarm on the dash and the buzzer starts going off. Its the light on the top left of the screen, just next to the parking brake light. I've checked all fluids and everything is good. No temps are getting high either. Is there any way to diagnose what this alarm is? A local fella told me that I should be able to turn of off and back on and it should flash in a sequence to give a morse code type of code like the old GM OBD-1 computer systems would but it is not doing this. The alarm is at a constant interval. The light continuously flashes and the buzzer is about every 3-5 seconds apart.
Call your local cat house. They should be able to tell you if and how to read a code
Your alert indicator is for low engine oil pressure. The oil level should have nothing to do with it. You may have a faulty pressure switch/sensor (not sure what that machine has on it), you may have a wiring fault, or it could be that the oil pressure is low with a warm engine, and by the symptoms you describe (light doesn't come on until the machine's been running 20 minutes or so) it could be that the pressure is actually low. I think the first thing I would do is try to plumb in a mechanical gauge to the location the pressure switch is installed and check what oil pressure you actually have. If the oil pressure checks out OK then go looking at the electrics.
How would you test a low oil pressure sensor?
First question. Sensor or switch..? Low oil pressure alarm devices are most often (but not always) a switch. Find out what the specification of it is, then connect it to shop air via a regulator and slowly raise the pressure to the whatever value is supposed to change state (open->closed or vice versa) at, and see whether in fact it does.