air intake heater

[defed]

how do you know if it is working? the dash light doesn't come on (at least i think the 'glow plug' light should come on), but don't know if the bulb is just out.

does it make any noise when activated? doubt that there is any sensor to keep it from working if it the outside temp is warm.

thanks.
Dave

[kennyd]

What tractor Dave? I am sure someone that has the FSM (factory service manual) will help with the diagnostics...but we need to know what machine you have.

[defed]

(2001) 4300...i just presumed that they would all operate the same in that regard!

thanks.

[JD755]

Different JD models engage the heater in different ways. The manual for yours says to push in the key.

I-Cold Start Indicator Light: Indicates that the ignition key is being pressed in and that the air manifold heater is on and heating the intake air to the cylinders, allowing faster starting in cold weather.

[Egon]

That surely sounds better than what I had in my now deleted post!

[defed]

Different JD models engage the heater in different ways. The manual for yours says to push in the key.

I-Cold Start Indicator Light: Indicates that the ignition key is being pressed in and that the air manifold heater is on and heating the intake air to the cylinders, allowing faster starting in cold weather.

correct, but besides the light, there is no way to know if it is active? i've used some (non-deere) models w/ plugs and you can hear it click and such when in use, even if the light was out.

since my light doesn't come on, i'm just wondering if the bulb is out or the switch isn't working. if there was some other signal that the heater was working, it would save some digging (IE pulling the instrument panel or switch).

thanks again.

[JD755]

The tech manual for your tractor shows the light is connected directly to the key switch, so either the bulb or the switch has probably failed. The heater is connected through a relay downstream, but I don't know how loud the relay might be.

[Dennisfly]

My 855 has the air heater system. When the outside temp is above a certain point (maybe low 60s) the heater is disabled and you will see no light.

If the temp is below that point, when you turn the key on but don't crank, the light illuminates for a period of time, activating the heater. When the light goes out, you begin cranking.

If you cycle the key without cranking through 2 or 3 heat cycles, you can place your hand on the air heater and feel that it is warm, confirming its operation. It is the plate that bolts between the air filter pipe and the intake manifold with a wire running to it.
Mine was inoperative for a time and it was a control relay that is mounted on the engine side of the firewall. Pulling the relay out of its socket and cleaning the contact prongs solved the problem.

Having said that, I find mine is not that effective. If it gets to the 30s or less, I use a block heater.

[JD755]

My 855 has the air heater system. When the outside temp is above a certain point (maybe low 60s) the heater is disabled and you will see no light.

If the temp is below that point, when you turn the key on but don't crank, the light illuminates for a period of time, activating the heater. When the light goes out, you begin cranking.

If you cycle the key without cranking through 2 or 3 heat cycles, you can place your hand on the air heater and feel that it is warm, confirming its operation. It is the plate that bolts between the air filter pipe and the intake manifold with a wire running to it.
Mine was inoperative for a time and it was a control relay that is mounted on the engine side of the firewall. Pulling the relay out of its socket and cleaning the contact prongs solved the problem.

Having said that, I find mine is not that effective. If it gets to the 30s or less, I use a block heater.

Your 855 works very similar to my 755, except yours has an intake air heater and mine uses glow plugs. Both use a temperature sensor to control operation and are activated by just turning the key to ON and waiting a few seconds before turning to START. The 4300 schematic shows it is a completely manual system with no sensors, and has to be activated by pushing in the key. I think you have a good idea to feel the heater, and in this case could be done by just pushing the key in while doing that. Cleaning the relay contacts is also good, but in this case there is less chance of that being the cause since the light is not working and does not go through the relay.

[defed]

thanks again for all the help. i will see what i can see.