299C - Temperature Gauge Increase / Fan Control Switch

[DanTX]

I'm sorry I don't. I would suspect that a wire open would trigger a Diagnostic Code.

However both the coolant temp and hydraulic temp sensors are a fairly simple 2-wire passive type with one side connected to ground. So it must be a variable resistance with temperature.

I think the very high difference in radiator inlet/outlet temperature warrants further investigation.

Thanks Nige, the only diagnostic codes are E361-3, high engine temp, and 1076-5 that I generated when I unplugged the wiring harness from the hydraulic fan solenoid. I'm going to be away from the machine for several days. I'll follow back up.

 

[Nige]

Simon, thanks for the input. The radiator is clean.

If I can throw anoother curve ball in here. Unless the cooling package (radiator and hydraulic oil cooler) has been removed and completely disassembled then IMHO you can't say it's clean. There is so much packed into such a small space that it is impossible to verify condition without removeal from the machine and complete disassembly. We've been here before........

 

[DanTX]

I wondered what was acceptable difference for the two radiator hoses. As I said in post #12, Not sure how much it should be at. Wonder if there could be some blockage in that radiator, and thought as you said Nige, that the trigger wire is either working or not working. I guess he will have to verify the simple stuff first.
Simon C

Thanks Simon, I'll be away from the machine for the next week. I'll do some more checking when I get back. If either you or Nige, or anyone else discover what an acceptable temp difference between the two hoses, please pass it along. Thanks

 

[Simon C]

Think a Photo tach with tape put on the fan might give someone an idea how fast the fan is turning.
One thing that I did not see after re-reading this is an Hour Meter reading. Maybe that fan is worn out.
Have seen on some other Skid Steers. Will find out when DanTX returns.
Simon C

 

[Nige]

If either you or Nige, or anyone else discover what an acceptable temp difference between the two hoses, please pass it along.

I posted it earlier. 20 Fahrenheit degress maximum (usually it is less than that) with a radiator in perfect condition both inside and out. You had a measured difference of 41. As the Chinaman would say - Sum Ting Wong.

 

[Simon C]

I seen your post above about 20 Fahrenheit, the one I wonder about is what is full RPM of fan when fan motor is good and at what RPM. It either turns the speed it is suppose to with signal wire hooked up and a call for cooling coming from the ECM or it doesn't. If I am wrong Nige, I am all ears.
Simon C

 

[DanTX]

If I can throw anoother curve ball in here. Unless the cooling package (radiator and hydraulic oil cooler) has been removed and completely disassembled then IMHO you can't say it's clean. There is so much packed into such a small space that it is impossible to verify condition without removeal from the machine and complete disassembly. We've been here before........

Think a Photo tach with tape put on the fan might give someone an idea how fast the fan is turning.
One thing that I did not see after re-reading this is an Hour Meter reading. Maybe that fan is worn out.
Have seen on some other Skid Steers. Will find out when DanTX returns.
Simon C

I posted it earlier. 20 Fahrenheit degress maximum (usually it is less than that) with a radiator in perfect condition both inside and out. You had a measured difference of 41. As the Chinaman would say - Sum Ting Wong.

Sorry I was driving and didn't see the temp difference. The machine has 3400 hours on it. I'll take the radiator off the machine and bring it to a radiator shop for a through cleaning. The hydraulic fan does not run at full speed unless I unplug the wiring harness to the solenoid.

 

[Nige]

he hydraulic fan does not run at full speed unless I unplug the wiring harness to the solenoid.

The fan will only run at high speed once the temperature(s) of the coolant and hydraulic oil are well elevated.

An inspection of the solenoid for the fan motor control solenoid, and maybe the fan motor itself, may be called for.

 

[DanTX]

Who knows, maybe I left a blue shop paper towel in the machine when I did the head gasket. I left one in the turbo drain line......

 

[Simon C]

So with harness to the solenoid unplugged, is it still overheating. If so, getting the Radiator cleaned out might be an okay idea, and like Nige said checking the fan motor control solenoid and fan motor itself might be a good idea. Have a nice week off.
Simon C

 

[DanTX]

The fan will only run at high speed once the temperature(s) of the coolant and hydraulic oil are well elevated.

An inspection of the solenoid for the fan motor control solenoid, and maybe the fan motor itself, may be called for.

I would have thought that the fan would have been running full bore when the temp was over 217. I don't believe it was. This leads me to believe there may be an issue with the fan motor solenoid since it was not running at high speed with the the high engine temp. It only ran at high speed when I unplugged the wiring harness.

 

[Nige]

I would have thought that the fan would have been running full bore when the temp was over 217. I don't believe it was.

The specified max fan speed with hydraulic oil at normal operating temperature is 2690 ± 50 RPM. You will need a phototach to measure it.

 

[Simon C]

I knew you would have the spec., on the fan speed. That would give a guy a good start. I have a Snap-On phototach from 1988 that works very well. If it is full speed, then radiator clean or repair. If not full speed, then fan motor or solenoid problem would be good to check.
Eventually the cause will be evident.
Simon C

 

[DanTX]

Simon, Nige, both of you mention to measure the fan speed with a photo tach. I don't have one but I'll either borrow or buy one. I'll measure the RPMs at normal operating engine temp as displayed on the panel of 195 degrees and different intervals up to the overhead alarm of 230 degrees. I'll also measure the speed with the with the solenoid wiring harness off.

 

[DanTX]

Good morning, picked up a photo tach and ran a test. Here are the results.

RPM @ Monitor Display Temp
470 @ 71 - right after starting machine
619 @ 100 degrees
820 @ 150
874 @ 175 -- engine at full speed
932 @ 200
1760 @ 206
-- turned on fan switch, temp jumped to 225, continued to climb to overheat alarm
-- removed wiring harness from fan solenoid, fan speed peaked @ 3048 rpm
-- turned off fan switch, plugged harness back in
-- temp dropped to 210
2261 @ 210
1400 @ 204 -- engine to idle
1483 @ 206 -- engine back to full speed

Thoughts?

Thanks, Dan

 

[Nige]

Thoughts?

Max fan speed appears to be good. Fan speed control control appears to be the problem.

 

[DanTX]

That's what I thought. I did pick up a new fan solenoid, so I''ll change it out and re-run the test.

 

[DanTX]

Fan speed appears to be fixed. It's now runs at 2680 +/- rpm when the temp hits 200'ish degrees and I can hear it engage. There is a but here.... The temp display does still jump 10 to 15 degrees when I turn the fan switch on. Turn the switch off and the temp returns. There are no active error codes, only the stored errors of E361-3, high temp error and 1076-5 error from when the wiring harness was unplugged from the fan solenoid. The temp will also jump 4 or 5 degrees when I move the machine forward. Any ideas?

 

[Nige]

I would suggest to measure how much amperage the heater fan motor pulls when it is activated. I suppose that there is a possibility of the sensor system performance changing but I don’t recall ever seeing it myself.

Also I would be looking at electrical grounding. Can to chassis, engine to chassis, everything basically. Do you have an electrical schematic.?

I guess a look at alternator output and belt tension:condition would also not go amiss.

 

[DanTX]

Thanks, I check the fan motor and alternator. Belt is good.

Grounding is the common denominator...