How many amps do glow plugs draw?

[Kubotafan]

I have a 3 cylinder G1800 Kubota lawn tractor. The glow plugs work if jumped from the battery, but not off the ignition switch. It is an older tractor and I am not wanting to spend a lot on parts so am going to wire it direct with a push button contact switch. I am wondering how many amps the three glow plugs draw so I will know what gauge wire I should use and proper size fuse to put in the circuit.

 

[Patches]

I'm not sure of the answer,but, glow plugs usually operate through a relay, which tells me you're probably not going to be able to operate them through a switch alone

 

[buickanddeere]

Just repair the factory wiring instead of some jackleg cob job.
Probably just a relay.

 

[arlen4720]

I agree with buickanddeere, just fix the problem. But to answer your question directly, they will probably draw more than 10 amps per plug, but less than 20.

 

[yankeerider]

When my Deere 755 was hard to start in the cold, I checked each of the glow plugs with my Fluke multimeter. One was a lttle over 1 ohm resistance, one was almost 2 ohms, and the third was open. Being a cheap yankee, I replaced only the the open one. The new glow plug tested at about 0.5 ohm. That'd correspond to 24 amps at 12 volts, vs. 12 and 6 amps, respectively, for the original 2. Adding them up, I get 42 amps. But remember, they're only energized for 20-30 secons at a time. That lets you get away with a smaller wire than needed for sustained operation.

I have a high performance radio controlled sailplane that pulls 90 amps at full throttle. The wire between the controller and motor is only 12 gauge, but is only 3 inches long and only energized for about 20 seconds at a time. Any longer, and the plane is too high in the sky to see clearly!

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[Kubotafan]

Just repair the factory wiring instead of some jackleg cob job.
Probably just a relay.

I think the problem may be the ignition switch, but not sure. I don't know if there is a relay or not but I can check with my dealer. I have held a length of wire on the first glow plug and the positive terminal at the starter and that energize the glow plugs and get the tractor started.

 

[k0ua]

I have a 3 cylinder G1800 Kubota lawn tractor. The glow plugs work if jumped from the battery, but not off the ignition switch. It is an older tractor and I am not wanting to spend a lot on parts so am going to wire it direct with a push button contact switch. I am wondering how many amps the three glow plugs draw so I will know what gauge wire I should use and proper size fuse to put in the circuit.

The ones on my Kioti draw almost 20 amps per plug, so it could be up to 60 amps. It might be less, they are not all the same, but like the above poster said, probably more than 10, and probably less than 20 amps each. What are the contacts rated for on that push button switch? I bet it is not 60 amps. Like another poster said.. repair the original circuitry and relay. You will be way ahead.

 

[Kubotafan]

The ones on my Kioti draw almost 20 amps per plug, so it could be up to 60 amps. It might be less, they are not all the same, but like the above poster said, probably more than 10, and probably less than 20 amps each. What are the contacts rated for on that push button switch? I bet it is not 60 amps. Like another poster said.. repair the original circuitry and relay. You will be way ahead.

The switch is a 60 amp switch.

 

[Kubotafan]

When my Deere 755 was hard to start in the cold, I checked each of the glow plugs with my Fluke multimeter. One was a lttle over 1 ohm resistance, one was almost 2 ohms, and the third was open. Being a cheap yankee, I replaced only the the open one. The new glow plug tested at about 0.5 ohm. That'd correspond to 24 amps at 12 volts, vs. 12 and 6 amps, respectively, for the original 2. Adding them up, I get 42 amps. But remember, they're only energized for 20-30 secons at a time. That lets you get away with a smaller wire than needed for sustained operation.

I have a high performance radio controlled sailplane that pulls 90 amps at full throttle. The wire between the controller and motor is only 12 gauge, but is only 3 inches long and only energized for about 20 seconds at a time. Any longer, and the plane is too high in the sky to see clearly!

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I figured I would use #12 wire. I have jumped it with wire that is likely 18 gauge. It did the job, but I could feel a little heat. It is in contact for only about 10 seconds, so I think the #12 will be fine. I was going to use a 30 amp fuse, but wasn't sure if that would work. I probably should have something a little bigger.

 

[Kubotafan]

Can anyone confirm if there is a relay and where it is located? Where could I find a wiring diagram?

 

[Kubotafan]

I have my switch for the glow pugs wired up with a 30 amp fuse in the fuse holder. I have started it several times, and it hasn't blown the fuse yet. Maybe after a few more times it will blow, or maybe the three glow plugs are drawing less than 30 amps. I only takes about 10 seconds to heat the glow plugs so maybe the fuse doesn't heat up enough to blow in that length of time. Time will tell if the modification was successful.