89 400 series 25A fuse blowing

[WheelPuke 78]

I have my 25A fuse blowing every time I put a new one in the slot. The old one was burnt up when I got the tractor put this year. It sat for a year with a dead battery. I stopped using it as much because the transmission is clattering pretty bad when taking off on second or higher. I had to replace the clutch belt a few years ago and couldn't get an OEM. Not sure what is the problem there that's another issue though.

 

I have checked the wiring and patched the worn spots where it could be grounding out. The fuse blows as soon as there is power to the system with the ignition off. I'm at a loss of what to check for at this point. Any input from someone who has had this issue would be appreciated. I'm not sure what these units are in the photos but do not know how to test them for a failure. They are directly in loop with the battery and the ignition loom looks to run into that 25A fuse.

[squonk 48,231]

What model tractor? We can look on the wire diagram and figure where to start looking. 

[WheelPuke 78]

It is a 414-8. Edit: I should have put the specific model. My inital thought was this would have been a base issue and the specific model may not have been important. That's my mistake.

Edited April 13, 2025 by WheelPuke
Clarity

[WheelPuke 78]

So looking at the diagram it looks like the starter solenoid (the gold thing in the picture below the battery) and starter are the other items directly in the circuit past the ignition. So if the fuse is blowing with the ignition off that would indicate to me that the ignition is shorting or grounding out? If the ignition switch were right the  current would not make it to the 25A fuse.

[gwest_ca-(File Mod) 12,511]

 

[WheelPuke 78]

Section 17 - 312-8, 312-A, 414-8 Single Cyl Wiring Diagrams.pdf

[WheelPuke 78]

I realized after poking and prodding about with a multimeter that I'm thinking about that wrong, the system doesn't work that way. It likley isn't the ignition. It is either likley the solenoid or relay. I had one last spare fuse to test with. I disconnected the relay from the solenoid and inserted the fuse. It did not blow. I turn the key to the on position and the check lights lit up. I flipped the test switch for the light pannel and the fuse blew. That makes me think that the relay  would be bad and/or there is another short in the wiring somewhere I missed. The test light pannel images seat switch, parking brake, clutch pedal, pto clutch, and engine oil. The first two are lit with the ignition in the on position. Those circuits are clutch pedal, pto clutch, and engine oil. At 1717 hours and 36 years it could be any of those circuits. The ones that see wear from movement are both clutch sensor circuits that would prohibited power from going through the system to start the engine if one of those clutches isn't in a neutral position.

Edited April 13, 2025 by WheelPuke
Android

[WheelPuke 78]

I went searching for the switches for the clutches. I found the pto switch. While looking for the clutch switch I founds this wire hanging against the clutch brake. Still looking for the clutch switch. This wire comes out of the loom by the seat switch.

Edited April 13, 2025 by WheelPuke
Cleaned up post

[midpack 1,148]

My 417 was doing that when I got it. Turned out to be the solenoid. The PO put a new one in but it wasn't bolted down (grounded). Attached it properly and the problem went away. Yours doesn't look bad, but it's worth a check 

[WheelPuke 78]

I'll give it a try Monday when I can go get more fuses. I burnt up my last one in testing. I'll pull it off and clean up the ground.

[gwest_ca-(File Mod) 12,511]

Wire with the green strip would be a light wire.

Look for the neutral/clutch switch being activated by the drive belt idler. Right side and you will see it if you look through the shifter slots in the flat panel in front of the seat.

[WheelPuke 78]

I found it on the right side of the compartment under the shifter face plate. Everything looks in order. I'm not sure how I can test it without more fuses at the moment.

[squonk 48,231]

Check your auto supply store for a circuit breaker. Put a fuse in when you find the problem and save the breaker for next time.

 

 

 

[WheelPuke 78]

I'll get one when I'm there Monday to get a new supply of fuses. I'd never thought of that.

[Handy Don 17,571]

2 hours ago, WheelPuke said:

I'll get one when I'm there Monday to get a new supply of fuses. I'd never thought of that.

Pretty cool how we learn from posts on this forum, isn’t it?!

[WheelPuke 78]

On 4/13/2025 at 8:21 PM, Handy Don said:

Pretty cool how we learn from posts on this forum, isn’t it?!

It sure is. It's great to be a member here and learn new things.

[WheelPuke 78]

So upon picking up a new set of fuses and a circuit breaker (30A 14V). I opted to test the switch of the two that was the easiest to get to. That is the clutch safety switch. Last week I pulled apart everything. So I first installed the circuit breaker with power to the system. It clicked and I verified that by attempting to key over the starter. Nothing. I removed the criuit breaker and then removed the connections to the clutch safety switch. I re installed the circuit breaker and held the connectors together and acrobatically held the clutch down while some help turned the key. No pops from the circuit breaker and the engine turned over. I repeated the test with a 25A fuse. Same results there fore the clutch safety switch has a short in it. Now it's back to NAPA to try and replace it or get a double blade of the correct size to by pass the switch in the mean time.

 

Thanks to everyone for their input. I have the problem solved.