Years ago, I bought an old Bobcat 753, and my brother joked that it looked like it had fallen off the back of a trailer on the way home. That winter, I decided to spruce it up and give it a little TLC. One issue stood out right away: the glow plugs didn’t work. My solution? Park it in the heated garage and let my wife deal with frosty car windows. Over the years, this workaround has done the trick—keeping it warm makes it start right up. However, if I leave it outside on a cold night, it’s a real struggle to get it going. The machine has the BOSS system, but the glow plug timer never counts down. It just displays zeros and then switches to the hour meter. I’ve tested all the glow plugs with a multimeter, and they’re good. However, there’s no power to the busbar, likely because the countdown never initiates. I called the local Bobcat service department, and they suggested it might be the relay. I replaced it (there are only two near the starter that I could find) and swapped them around to test, but no luck. One of these relays also controls the starter, so I tried their advice, but the glow plug system still doesn’t work. I’ve considered adding a manual switch to power the busbar, but I’d prefer to fix it properly and have the timer work as intended. Does anyone have advice on what else to check or troubleshoot to figure out why the countdown won’t start? Thanks in advance for any help!
There is more than one schematic for Kubota engines if that is what you have. I have 2 different schematics for Kubotas, but there is more. On the back side of your key switch is either numbers ( 30, 50, 17, 19 ACC ) or Letters such as Batt, Acc, Glow , ST ,. Your key switch itself might be faulty . Might be worth checking if it is numbers or letters on the back side of the switch. Someone who has the exact schematic might send it to you. Post your serial number as change ups are happening all the time.
I did get a new switch a few years ago, but I got it from Bobcat so I think they gave me the right one. I'll have to pull that panel off and have a look at it.