BOSS Voltage Question

[wildfan]

I have a 753 with BOSS. Does anyone know what the supply voltage is to the temperature sender? I currently have 3.5V. I put a 160 degree thermostat in and the gauges never go above one bar, which from my understanding might be expected as I read on another thread, that bar 2 displays at 180 degrees.

 

[wildfan]

I've been running this machine for about 10 hours and it still never goes over 1 bar. The engine definitely is not running hot. I had replaced the cylinder head, water pump, thermostat and temp sensor and it's running great. At this point, I'm not tooo concerned about it displaying only 1 bar.

 

[Old_853]

It doesn't work like you think it does. BOSS uses SAE J1939 CAN Bus protocol to communicate with the sensors. If you installed a sensor that is not canbus, it won't give an accurate reading. Use bobcat parts catalog to enter the info for your machine and find the exact part number based on your serial number. Then order that part. People have converted to manual gauges and left the boss system active, but isolated. That's a big project though, better to just get the right sensor. Parts lookup

 

[wildfan]

It doesn't work like you think it does. BOSS uses SAE J1939 CAN Bus protocol to communicate with the sensors. If you installed a sensor that is not canbus, it won't give an accurate reading. Use bobcat parts catalog to enter the info for your machine and find the exact part number based on your serial number. Then order that part. People have converted to manual gauges and left the boss system active, but isolated. That's a big project though, better to just get the right sensor. Parts lookup

 

[wildfan]

The new sensor was purchased at Bobcat using my serial number. I do notice that on cooler mornings it shows no bars for a period but it still never goes over 1 bar regardless.

 

[Old_853]

Well that's good I guess. I did find this-
TEMPERATURE SENDER
70 degree F. (21 degree C.) 970 ohms. . . . . . . . . . . . .
80 degree F. (27 degree C.) 1013 ohms. . . . . . . . . . . .
ENGINE OIL PRESSURE SENDER
0 PSI 3 ohms Max.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 PSI (41 kPa) 7 ohms Min.. . . . . . . . . . . . . . . . . . . . . . .
50 PSI (345 kPa) 49 ohms. . . . . . . . . . . . . . . . . . . . . . . .
70 PSI (483 kPa) 59 ohms. . . . . . . . . . . . . . . . . . . . . . . .
TRANSMISSION CHARGE PRESSURE SENDER
0 PSI 0–5 ohms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
100 PSI (690 kPa) 58 ohms. . . . . . . . . . . . . . . . . . . . . . .
130 PSI (896 kPa) 75 ohms. . . . . . . . . . . . . . . . . . . . . . .
150 PSI (1034 kPa) 87 ohms. . . . . . . . . . . . . . . . . . . . .
FUEL SENDER
Full 30 ohms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Empty 270 ohms. . . . . . . . . . . . . . . . .

 

[wildfan]

Thanks. It's kind of a PITA to get to, but I will definitely check this out before the weather warms up. Last fall before I parked it, I noticed the glow plugs wouldn't energize when it was maybe 50-55 degrees. This spring, in about 45 degrees, the BOSS displayed glow for about 10 seconds and it fired right up. I'm just concerned about overheating after replacing everything. The older I get, the less excited I am at doing major engine work. This weekend's project is that I get to replace the carriers. I knew there was a leak into the chain case when I bought it from the local farmer and I was assuming just carrier seals. The farmer must have used an air chisel inside the carriers at some point and I have huge gouges from where the races sit through to where the carrier seal sits and even all the way to the outside where the o ring from the drive motor seals. Fun times!

 

[Old_853]

Mine is also farmerized. I find evidence everytime I take something apart.