A90 john deere shop heater

railhead · Dec 5, 2009

Well my faithful A90 quit me today. Heated nicely yest but this AM when I turned it on it hums but motor won't turn and trips breaker on the heater. I have done NOTHING to this heater except change the spark plug ONCE. Have always burned diesel in it, never kero. I took the shroud off and the fan and motor turn very hard...unlike any other elect motor I have that ..any suggestions??? should this motor turn hard? TIA

msb · Dec 5, 2009

Sounds like the nozzle could be plugged.

whizkidkyus · Dec 5, 2009

Railhead ,

Sounds more like the bearings in the motor are locking / locked up and need replacing . You may be able to get an electric motor repair shop to replace them or you may have to buy a new motor. If the bearings are bad then the motor can't turn as easily and freely, this would then overload the breaker by it pulling to many amps trying to turn over and run. Electric motors should turn freely, but the bigger the motor is , the more force that is necessary to turn it over . But this is just my two cents worth.

Whizkidkyus

whizkidkyus · Dec 5, 2009

Railhead ,

Sounds more like the bearings in the motor are locking / locked up and need replacing . You may be able to get an electric motor repair shop to replace them or you may have to buy a new motor. If the bearings are bad then the motor can't turn as easily and freely, this would then overload the breaker by it pulling to many amps trying to turn over and run. Electric motors should turn freely, but the bigger the motor is , the more force that is necessary to turn it over . But this is just my two cents worth.

Whizkidkyus

whizkidkyus · Dec 5, 2009

Railhead ,

Sounds more like the bearings in the motor are locking / locked up and need replacing . You may be able to get an electric motor repair shop to replace them or you may have to buy a new motor. If the bearings are bad then the motor can't turn as easily and freely, this would then overload the breaker by it pulling to many amps trying to turn over and run. Electric motors should turn freely, but the bigger the motor is , the more force that is necessary to turn it over . But this is just my two cents worth.

Whizkidkyus

Uncle Ernie · Dec 5, 2009

Try a little light lubricant on the motor bushings. Sewing machine oil or 10wt hydraulic fluid. Something with some lubricating capacity more so than WD 45 or a penetrating oil. They should free up and start spinning again. If not WW Grainger has a large selection of fan motors.

NCWayne · Dec 5, 2009

It sounds like the bearings have gotten dry to the point it needs too much force to turn so it's drawing more amperage than usual to get it started spinning. Many of those small motors are very easy to take apart and re-grease or re-oil the bearings. Usually it's just a couple of long bolts through the ends and the main body of the motor. The thing to so is to mark both ends, pull it apart. When you do this keep an eye out for any wave springs that are usually used on the ends next to the bearings and make sure if present they don't get lost or put back in the wrong place. Once apart re-grease/re-oil as needed, then reassemble. Look at it this way, if it already doesn't work then your not out anything to see if you can get it apart and repair it. I've got several heaters, etc around that have small motors in them and I usually have to open up the ones that don't have oil points every few years and re-oil them. I've never had a problem getting them spinning free again doing this.

S.Crum · Dec 6, 2009

Sounds like some crud has accumulated in the compresser pump. This is at the back of the motor and has a carbon wheel with 4 carbon vanes in it. It's a very close tolerance unit so be careful as you can crack the wheel in half. These are no longer available but an expensive conversion is. Take the compresser apart and clean it good but don't use solvent just water and wipe off. DON'T use oil on the rotor or vanes, just be sure the vanes work smooth in the slides. A drop of 30W small motor oil in both motor bushings should be good.
I had to stop using my 'salamanders' a couple years ago due to asthma. Much cleaner and quieter using an old oil furnace and really no more expensive.

GordoSD · Dec 6, 2009

Farm stores sell repair kits for a lot of them. Look at the compressor and the motor. Prolly just some air and lube will get your warm again.
They are making some nice high output propane units now. Marketed as garage heaters, but interesting enough, it's the way most homes in Japan are heated.Just a LARGE radiant propane heater with a tiny fan.
I keep one on hand for power outages. Can heat up two big rooms with it. About 800 sq feet, 9 foot ceilings.

Gordo
Gordo

Bob · Dec 6, 2009

As the others say, first check that the motor turns easily (no sticky bearings or jammed/broken air pump vanes) and correct any problems there.

If that's OK, there's a start relay for the motor (similar to those used with hermetic refrigeration compressors) that could be stuck/burned/damaged/defective.

Most parts are still available through DEERE, and you can see a parts breakdown for the heater at www.jdparts.com. There's a serial # break or two, so have the serial # at hand when looking for parts.

Ole Shovel · Dec 6, 2009

See if you can find a parts breakdown for it in parts catalog section after getting to jdparts.com JD didn"t make it just sold it with their name on it. Reddy Heater probably made it and will have parts for it for less $$$. Either the motor bearings have failed and locked up or the pump is locked up that is driven off the motor shaft. Most motors on those can be oiled once a year or so. If the pump has locked up and motor is free you can get just a vane kit or a rotor and vane kit unless the pump is ruined. If had trash in fuel and the filter screen came off bringing trash into the pump it could be ruined but it probably just wore out. Can get maintenance kits for those heaters has new air inlet foam, gaskets, and pump vane kit. Probably a good idea to get a new filter screen too. One the motor Reddy Heater will have it or Grainger an electric motor shop and Grainger has heater kits too.
Reddy Heater

Kentb of SWMO · Dec 6, 2009

If the motor turns but still hums when turned on look for a motor starter switch not making contact.

Kent

Bob · Dec 6, 2009

Kent, as I already told him, it uses a start relay similar to a hermetic compressor and has NO starting switch in the motor.

(I verified this on the jdparts site.)

railhead · Dec 7, 2009

s.crum you're the man but ALL HELP APPRECIATED.

runs like a singer sewing machine again.

Cavalierjoe · Jan 6, 2016

Ok guys next question: I have the A90 also and I'm looking for a new fan blade! Does anyone have one for parts laying around? I can not find one online anywhere. Give me a price I'll buy it right now thanks !!!! [email protected]

A90 john deere shop heater

railhead

Member

msb

Well-known Member

whizkidkyus

Member

whizkidkyus

Member

whizkidkyus

Member

Uncle Ernie

Member

NCWayne

Well-known Member

S.Crum

Well-known Member

GordoSD

Well-known Member

Bob

Well-known Member

Ole Shovel

Member

Kentb of SWMO

Well-known Member

Bob

Well-known Member

railhead

Member

Cavalierjoe

New User

Similar threads