Starter relay fuse keeps blowing

[tassmannn]

I have a Deere 5045E that was running fine. I went to start it tonight and it cranked over, but the wouldn't crank after that. So, I started researching from starter back. Here is what I found. There is a 10 amp fuse that says starter relay that was blown. I put another one in, and when I turned key on, it blew before even trying to start. I took the relay in the fuse box out, replaced the fuse. When I turned on key...no blow, and it even attempted to start, but would only crank. I thought oh the relay is shorted. The neutral relay is the same type so I swapped them...it blew again. So I am thinking that something down the line is shorting it....any ideas?

Thanks in advance...this is my first post. I searched a bit but didn't see this issue. Will continue to search though.

 

[beenthere]

To check it out, put a 12v light bulb in the fuse slot.. as long as there is a short the light bulb will be lit. When you isolate the short.. the light will go out.
Think that will save on your fuses and help diagnose where the trouble is at.

:welcome: to TBN

 

[tassmannn]

Thanks Beenthere. Not quite sure on what you mean about the 12v bulb since the fuse slot is just a bridge of positive. I would think if I put a test light on the down stream side of the fuse and put the other end on positive terminal as long as it stays on, it is grounded somewhere, but will turn off if I find and remove the sho. I just don't know where to look and I can't seem to find the wiring diagram, and there doesn't seem to be much wiring anyway, but don't really know where to look for the short. I will ask Ag Pro tomorrow.

 

[Dave M7040]

I have a Deere 5045E that was running fine. I went to start it tonight and it cranked over, but the wouldn't crank after that. So, I started researching from starter back. Here is what I found. There is a 10 amp fuse that says starter relay that was blown. I put another one in, and when I turned key on, it blew before even trying to start. I took the relay in the fuse box out, replaced the fuse. When I turned on key...no blow, and it even attempted to start, but would only crank. I thought oh the relay is shorted. The neutral relay is the same type so I swapped them...it blew again. So I am thinking that something down the line is shorting it....any ideas?

Thanks in advance...this is my first post. I searched a bit but didn't see this issue. Will continue to search though.

tass.......

Some thoughts for you to consider.

In addition to engaging the starter, the relay may also interact with the fuel cut off solenoid allowing the tractor to receive fuel to the injectors. However, after reading your post again I am puzzled. You seemed to say that the starter engaged without the starter relay installed. Is this correct?

The fuel cut off solenoids have two electrical windings inside. A high current one to pull the solenoid plunger and a low current one to hold the plunger once it is pulled.

Can you locate this solenoid on your tractor's injection pump? Perhaps with your common rail system you dont have this component.

If you can, then disconnect the electrical connector for it and then see if your fuse still blows. The tractor wont start but should turn over.

How old is your tractor?

Do you have a wiring diagram you could post for us to study?

Later thoughts.

Your tractor is described as having an electronic common rail fuel system so my thoughts on the fuel cut off solenoid may not apply.

Newer tractor often have a diode in parallel with the starter solenoid to adsorb what is called a back electromotive force to be technical. A solenoid builds up a magnetic field around its coil and when the power to it is suddenly cut off, the collapsing electrical field can generate a very high voltage pulse of energy which can damage electronic components,

Has your battery been disconnected recently? Have you boosted the battery or connected a charger? Some of these done wrong can blow the diode and then you start blowing fuses.

These images show one of these diodes on another machine.

Note the diode symbol

Dave M7040

 

[tassmannn]

Dave,

It is really hard to explain this in these threads. There is a relay in the fuse box that says starter relay, and a 10 amp fuse that says the same. When I popped the relay out, the tractor would turn over, but when I put it back in...or another one the 10 amp fuse would blow. I'm thinking that whatever the starter relay is connected to is causing the short. I think I know where the fuel disconnect is as these are similar on a lot of these types of pumps. My 6.9 idi is very similar. tractor is about 5 or 6 years old, and I so wish I had or could find a wiring diagram. I started this all tonight when I got home, and I am hopeful the guys at the Ag Pro dealer can give me an Ah Ha moment tomorrow. We ran the tractor for four days with no incident after hurricane Irma running a PTO generator. I just got on her to start it to move it, and this happened.

Thanks again Dave!

 

[beenthere]

This is my fuse replacement tester.. just solder some wires to a blown fuse so the light bulb is in place of the fuse.. instead of blowing, it will light. Your fuse may look different than this spade fuse.

 

[Dave M7040]

Dave,

It is really hard to explain this in these threads. There is a relay in the fuse box that says starter relay, and a 10 amp fuse that says the same. When I popped the relay out, the tractor would turn over, but when I put it back in...or another one the 10 amp fuse would blow. I'm thinking that whatever the starter relay is connected to is causing the short. I think I know where the fuel disconnect is as these are similar on a lot of these types of pumps. My 6.9 idi is very similar. tractor is about 5 or 6 years old, and I so wish I had or could find a wiring diagram. I started this all tonight when I got home, and I am hopeful the guys at the Ag Pro dealer can give me an Ah Ha moment tomorrow. We ran the tractor for four days with no incident after hurricane Irma running a PTO generator. I just got on her to start it to move it, and this happened.

Thanks again Dave!

In looking on the Deere web site it appears your engine does not have glow plugs in the usual sense but instead a grid type heater in the intake manifold. Also there is a temp sensor near the thermostat which, in some fashion, sends a signal to advance the fuel injection timing when the engine is cold.

The more electronic these machines become the harder it is for the ordinary owner to fix them.

Dave M7040

 

[Tx Jim]

Sounds as if cold start switch has shorted out. Unplug switch,install new fuse & attempt to start tractor. If engine starts & runs you've located your problem. These switches have a long/long history of failure. RE503242 Temperature Switch - ADD 49.58 USD

 

[tassmannn]

Sounds as if cold start switch has shorted out. Unplug switch,install new fuse & attempt to start tractor. If engine starts & runs you've located your problem. These switches have a long/long history of failure. RE503242 Temperature Switch - ADD 49.58 USD

Jim...you are a rock star! Unplugged switch and put in new fuse....cranked right up! Any Idea where I can get a wiring diagram without buying the entire shop manual?

 

[tassmannn]

This is my fuse replacement tester.. just solder some wires to a blown fuse so the light bulb is in place of the fuse.. instead of blowing, it will light. Your fuse may look different than this spade fuse.

Beenthere...that is a pretty cool little tester you made there. I will make a couple variations for different fuses. Thanks for sharing