The glow plug indicator light is not lighting up and so the glow plugs are not heating. Tractor won't start. I checked the indicator light on dash and it is good. I am thinking it is the relay switch. Is there a way to test the switch? Or does anyone else have any other thoughts?
Glow plug relay switch
- Thread starter questadg
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Oldtractorfixer
Gold Member
Do you have power at the glow plugs? What make and model is your tractor? burned out glow plugs? Some glow plugs are wired in series, some Parallel.
also check for bad connections.
also check for bad connections.
3820i. I checked voltage at glow plug terminals and the terminal that feeds them. No voltage. I then decided to trace back and the manual shows a glow plug relay. My idea is to test that thinking that that is what controls power to the plugs and also the timer that eventually kicks off power to the plugs. I can check for power coming in to switch but am not sure how to test the switch or if it can be tested. I am thinking that if glow plugs are bad I will still be reading power to them that is why I have eliminated the theory that the plugs are bad. Am I wrong on this? Thanks for the reply.
Happy thanksgiving!
Happy thanksgiving!
Oldtractorfixer
Gold Member
You are correct that if there is no power to plugs they are most likely good. To test relay. It should have 4 wires to it. Constant power, Power out to load (plugs), switched power and a ground. Many relays have the wiring diagram printed on the side of them. The constant power and power out will be bigger wires. So to test, make sure one wire is grounded. (It is possible they switch the ground but if that is the case you will have power to two posts.) To test relay apply power to the switched terminal. This should close the circuit and supply power to the load. If this works then you need to work back to the switch. Jumping between the two big wires (constant power and load) should make the glow plugs work (but maybe not the light) even if the relay is bad. Good luck.
Zork
Veteran Member
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- '04 Branson 3520, '51 Fergy, '96 MTD 18/46, '02 Craftsman GT5000/48
View attachment 290540
There may be a fuse. You haven't posted which tractor it is for.
You can see if the Bransonson site has the information on: Branson Tractors - (North America) - Home
Then click "PARTS" and enter your tractor model and engine type and scroll through the menu.
There may be a fuse. You haven't posted which tractor it is for.
You can see if the Bransonson site has the information on: Branson Tractors - (North America) - Home
Then click "PARTS" and enter your tractor model and engine type and scroll through the menu.
