tc35d #2 fuse blows intermittently

[tobitobi]

Over the last several years (intermittently) I've been having issues with my tc35d #2 fuse blowing when trying to start the tractor. Always seems to happen once I've had the tractor running for some period. I'll let the glow plug light go out, turn the key and you can hear a click as the fuse blows. Replacing the fuse and repeating provides same results. Once the tractor sits for a while @1/2 hour or more, it magically starts the way it should. I've changed the fuse from the stock 7.5a to 10a, confirmed no wiring issues, replaced the fuel solenoid ...it almost seems to be heat related, as the but the running temperature is normal.

I know the cruise and dual speed switch runs through this fuse, but eliminated those, as well as the fuel solenoid (replaced). Is there anything from the starter, (such as starter solenoid, or perhaps starter sticking etc...??) also going through the #2fuse? Not sure what else to consider.

My local (small) dealer has no suggestions or additional ideas.

Any suggestions?? Appreciate any input.

 

[jinman]

I answered your PM with a link to a self-resetting circuit breaker at NAPA.

 

[tobitobi]

JINMAN,

Thanks for the link, I'll pick one up asap. What about a time for reset? Do you have to wait or just keep trying until it turns over and starts?? Sorry to keep bugging you, but this has been a huge problem over the years as it happens in many in-opportune times. Thanks again. Jim

 

[tobitobi]

JINMAN,

One other thing-- I have been running a 10A fuse in the #2 slot for some time now, and it still blows occasionally.

I see from the attached previous threads that the fix is supposed to be a 10A fuse- if so, why does mine still blow? Any harm in moving up to a 15A?? Thanks in advance.

 

[jinman]

The CB resets within 5 to 10 seconds; not a big deal. I think a 10 amp would be fine and you wouldn't see too many problems. A 15 amp is double the original value and could cause wires to get pretty warm. I'd try to find a 10 amp and only go to 15 amp if that's all I could find. Of course, you could by one of each and be prepared if the 10 amp opens too often.

 

[tobitobi]

That's what I'll do. Thanks a lot!

 

[tobitobi]

One last piece of information I wanted to share--

When questioning why the 10 fuse still blows occasionally, I've been told that the fuse will blow immediately while a 10A CB has a better tolerance for the spike in amperage. Installed the 10A CB yesterday.

Ready for this, shortly afterward, the #4 fuse blew--1st time ever in 10 years! Hope it's just one of those wierd coincidences that I tend to experience often.

 

[barbqranch]

Actually, fuses and circuit breakers almost all trip due to heat in some sort of resistive element. (There are a few modern exceptions, but not of concern here.) A fuse is basically a strip of metal with a low melting point and higher resistance than copper. The type in tractors are probably all the "fast blow" type, just a resistive metal. They are designed to not blow at the rated current, and how quickly they blow depends on the amount of overload. There are also "slow blow" fuses that can stand a higher overload for a short time, such as for an electric motor starting.

Circuit breakers usually have a resistive element that trips a bimetalic strip like in a home thermostat, to either automatically or manually be reset.

Vibration is also a factor, but not a big one. Corrosion on the fuse holder can lead to heat, causing the fuse or circuit breaker to trip earlier.

More than you wanted to know about fuses, most likely.

 

[jinman]

Ready for this, shortly afterward, the #4 fuse blew--1st time ever in 10 years! Hope it's just one of those wierd coincidences that I tend to experience often.

Fuse #4 is the rear fender signal/flashing lights and rear worklight power plus the instrument panel lights. It's power is used to energize the relay that turns on the main headlights, but the main headlight power comes from fuse #7. Is it possible that something in the instrument panel harness shorted out while you had it out and worked on the fuses?

 

[tobitobi]

No, just replaced the fuse with the CB as I've done a hundred times before. Clinging to the wierd coincidence for now. I'll follow-up if otherwise.