I'm having trouble with a 303e s/n SMG01318. It was working fine. They went to start it and it would not crank. The display lights up. None of the fuses are blown. It is not getting power to the start relay terminal 30. If I put power to terminal 87a, I think, with the key on it will start and work fine. I need to figure out why there is no power to the start relay. Does anyone have a wiring diagram? It would save alot of time chasing wires.
So I found the problem. Kind of dumb, but I didn't know. They took the keys out of the machines. When they came back to move them they went around putting CAT keys in the the machines. This machine has a chip in the key. Once I found the right key for it the security light turned green and it started right up.
I ordered spare keys from eBay for my 2018 CAT mini excavator. They were super cheap, fit fine, and look better than the one that came with it. Too easy . . . for me or anyone else! I think I'd rather have the chip!
That was the problem with the OP’s machine. Someone had put a “standard” key in a machine equipped with an MSS Security System. Such machines require the use of a key with a transponder in it. Said transponder deactivates the MSS and allows the machine to power up.
I have insurance, I dislike any security systems. They seem to bite you in da ass, more than ever help.
Well, I usually don't park my digger in the bad part of town while I go see a movie, but it does seem kind of lame that every single digger has the exact same $0.89 key -- at least for my year.
That key has had the same “business end” (although the “handle” has changed a few times) for probably the last 50 years. In that time I think there have been 4 different variations on basically the same key. Google 5P8500 and look at the images.
So you’re telling me, my Cat key from 35 years ago will still work? I still have a milkcrate of Cat locks, I have been moving from home to home, from back when I did roadwork. Every new Cat we got came with locks on all the panels. Ended up just throwing them in a milk crate.
As usual it’s all been discussed before. See this thread. Old Style Caterpillar ignition key Nige, Bob, anyone? I need a part number for the old style ignition key. The one with the little square head. 199-6309 5P-8500 current keys are not right. HeavyEquipmentForums