joispoi
Senior Member
Hi all.
I picked up an old Bobcat 331 last fall. It was neglected by its previous owner(s). I've gotten most of the bugs worked out of it and it's been earning its keep for the most part. However, there's one issue that I haven't figured out, yet. Once it gets up to working temperature, the coolant light comes on and the buzzer goes off.
Here's what I know:
The cooling system is full of new coolant.
The water pump is circulating coolant.
Using a laser thermometer, the oil pan is at about 185-186 degrees F.
The thermostat housing where the temp sensor is, is at 150 degrees F. (so is the radiator)
Yet the coolant light comes on and the buzzer is complaining.
Voltage at the battery (terminal to terminal) is 12.86v. Same reading from the positive terminal to the frame.
With the ignition key in the "on" position, the wire that attaches to the temp sensor is showing 11.75 volts.
With the ignition key in the "off" position, that same wire shows about 300mv. The wires at the the back of the instrument cluster also show about 300mv when the ignition is off.
Sometimes the the temperature gauge will drop to all the way to the left (zero), with the buzzer still sounding. (I don't know how to interpret that symptom).
Questions:
1. Shouldn't voltage be at 0mv with the ignition off?
2. Would moisture in the ignition switch or somewhere else cause this? (There is some condensation inside the gauge assembly).
Does anyone have a service manual or electrical diagram they could share? Has anyone had this issue before?
Any help pointing me in the right direction would be greatly appreciated.
Thanks
I picked up an old Bobcat 331 last fall. It was neglected by its previous owner(s). I've gotten most of the bugs worked out of it and it's been earning its keep for the most part. However, there's one issue that I haven't figured out, yet. Once it gets up to working temperature, the coolant light comes on and the buzzer goes off.
Here's what I know:
The cooling system is full of new coolant.
The water pump is circulating coolant.
Using a laser thermometer, the oil pan is at about 185-186 degrees F.
The thermostat housing where the temp sensor is, is at 150 degrees F. (so is the radiator)
Yet the coolant light comes on and the buzzer is complaining.
Voltage at the battery (terminal to terminal) is 12.86v. Same reading from the positive terminal to the frame.
With the ignition key in the "on" position, the wire that attaches to the temp sensor is showing 11.75 volts.
With the ignition key in the "off" position, that same wire shows about 300mv. The wires at the the back of the instrument cluster also show about 300mv when the ignition is off.
Sometimes the the temperature gauge will drop to all the way to the left (zero), with the buzzer still sounding. (I don't know how to interpret that symptom).
Questions:
1. Shouldn't voltage be at 0mv with the ignition off?
2. Would moisture in the ignition switch or somewhere else cause this? (There is some condensation inside the gauge assembly).
Does anyone have a service manual or electrical diagram they could share? Has anyone had this issue before?
Any help pointing me in the right direction would be greatly appreciated.
Thanks