No glow plug light/function

tman1020 · Oct 25, 2018

Went to start my tractor this evening and glow plug light did not come on right away then came on briefly and went out. tractor wouldn’t start and smoked like crazy now that it’s about 50° here. so turned off and try again no luck. Gave it some time and tried again still no glow plug light even if I use the key bypass.
I tried switching out the number 2 Glow plug timer relay with a matching one from the low beam lights no luck.
Check fuse it’s good. I’m thinking maybe the number 4 glow plug relay.
Any thoughts? Part is about 60 bucks

gimmodog · Oct 25, 2018

This probably will sound rude to some but that is not my intentions I am really trying to help you. you can buy and replace parts you THINK or what others think could be the problem or get out the multi-meter and do some troubleshooting and find the actual problem. If you don't know how to use a multi-meter you can use a 12v continuity tester light. A multi-meter is not hard to learn how to use and is a very useful tool. It will save you a lot of time and money in the long run.

winston1 · Oct 25, 2018

May not help but no charge.

tman1020 · Oct 27, 2018

Spent a little bit more time yesterday trying to figure it out. Tested power at the plug of the preheat controller. Seems like it’s getting power but not sending out power so I am guessing this is what I need. I originally priced out the part through a kioti dealer and it was about $60. Through bobcat it’s only $19. So the part is on the way hopefully I got it figured out we shell see.

SSdoxie · Oct 27, 2018

tman1020 said:
Spent a little bit more time yesterday trying to figure it out. Tested power at the plug of the preheat controller. Seems like it’s getting power but not sending out power so I am guessing this is what I need. I originally priced out the part through a kioti dealer and it was about $60. Through bobcat it’s only $19. So the part is on the way hopefully I got it figured out we shell see.

Just to verify your tests: In your opening post you stated no preheat with either key on in Run or manual preheat (key held to left). These are 2 separate until they tie together at the preheat relay. The controller/timer will have power to it with key on but output to activate the preheat relay will only be for initial 20 - 25 seconds the timer shuts off. The manual key mode sends voltage to the preheat relay by-passing the controller to activate the relay. Both activation wires are connected to the same post at the relay. You mentioned swapping relays but keep in mind, although the preheat relay appears the same physically as the starter, fuel solenoid, and headlight relays it has a different part number because it is rated for 70 amp versus lower amperage for the others.

tman1020 · Oct 27, 2018

SSdoxie said:
Just to verify your tests: In your opening post you stated no preheat with either key on in Run or manual preheat (key held to left). These are 2 separate until they tie together at the preheat relay. The controller/timer will have power to it with key on but output to activate the preheat relay will only be for initial 20 - 25 seconds the timer shuts off. The manual key mode sends voltage to the preheat relay by-passing the controller to activate the relay. Both activation wires are connected to the same post at the relay. You mentioned swapping relays but keep in mind, although the preheat relay appears the same physically as the starter, fuel solenoid, and headlight relays it has a different part number because it is rated for 70 amp versus lower amperage for the others.

The relays that I swapped had the same numbers on it. I pulled one from the headlights with the same number and switched it with the pre-heat relay. The pre-heat controller is a much different size in different part number and I did not have anything to swap with that one. That is the part I just ordered it was a little more expensive than the other relays.
Thank U all as always for the replies I will let you know what happens.

tman1020 · Oct 31, 2018

Well I’m stumped. Changed the pre-heat controller thinking that was the problem and it is not still no glow plugs.

tman1020 · Oct 31, 2018

Maybe the relay that my manual is telling me his preheat is not. Does anyone have a part number for a pre-heat relay?

tman1020 · Oct 31, 2018

Scratch that I think I might have figured it out. SS DOXIE Something that you said in your post got me double checking. I compared all my relays on the dash and noticed only one of them was rated for 70 Amps. It was located in what my manual says is the fuel pull location. So I removed that relay buy sliding it out just a little so I can get a electrical tester on there and sure enough it’s getting 12 V power in but not sending it out when I asked for power to preheat. So I will order one tomorrow and keep you all informed.

tman1020 · Nov 6, 2018

Well thanks to you all that posted help I believe the problem is solved. Gimmodog for the motivation to test, winston1 for the schematic, and ssdoxie once again your the man. Glad this site is here and you guys taking the time to help.
I don’t think I would have figured It out on my own.
Replaced the 70 amp relay and wall-a! I have glow plug fiction! Didn’t start it but I think I’m good.
Sincerely thanks again.