TC-33 Blowing the #2 Fuse

[dqdave1]

Clean the ground wire from the battery to the frame. Clean it at the frame connection. these can get corroded at that point. If it is corroded you will pull more amps. You could also put an amp probe at the fuse connection and see actual amps it is pulling by the fuse. It is possible that a piece of wiring in that circuit has high resistance do to corrosion, dirty connection etc. Clean all connections on circuit. Most circuits that need a slight increase in fuse size is do to engineering errror. You should not need to double size. If it is pulling 11 amps then you could put in a 12 amp fuse since it pulls high amps for short time. Trace wires and look for a suspicious wire. Smashed, discolored etc. Change it out if needed. With an amp probe connected; clean one terminal at a time and recheck amp pull. You will find the problem hopefully. If you have luck like I do, it will be the last connection you check!

 

[jinman]

If it is corroded you will pull more amps.

Dave, that is just not a true statement. Corrosion reduces current. If it increased current, we'd all love it. A weak battery with low voltage can cause some problems with this circuit, but corroded battery terminals will not cause this problem.

 

[tkcomer]

The manual only calls for a 420 CCA battery. That seems kinda low for this size engine. I understand (Kinda) a low voltage battery will cause a circuit to pull more amps. But I’ve never had any other vehicle or piece of machinery pop a fuse when the battery is low. Ever. But I do understand this is a not too common a problem on these tractors. Seems to me the fuse is under rated for the current draw. This fuse will pop before the starter kicks in and has a chance to even put a strain on the battery. Right now, it is starting fine with the 10 amp fuse I put in. But this kind of problem concerns me. The replies I’ve gotten have been great. Gave me things to think about. That’s why I like this board.

 

[SteveInMD]

I don't own a 33.. but I'm guessing the power for the starter doesn't go thru that fuse... er.. or any fuse..

The premise is still correct however.. a low battery menas more amps needed.. etc.

I'd recomend a self resetting CB...

Soundguy

Yes, you are right, of course the starter juice doesnt go through a fuse. However, if you are cranking the starter and running the glow plugs at the same time, you will get a bigger voltage drop from your battery, which will increase the amps on the fuse.

 

[tkcomer]

That’s just it. Glow plug light is out. Starter does not have a chance to even engage. The fuse pops way to quick for the starter to draw down the battery. Right now, the tractor has been starting every time today with the 10 amp fuse. But then last week, it popped two fuses in one day. The best I can tell, this fuse is tied to all the safety start switches. Seat switch is bypassed. I keep thinking a switch is messed up. If I could figure out which one, I’d bypass it. Way too many safety switches on this tractor. But then again, I’m old school. Clutch switches used to tick me off when they showed up.

 

[SteveInMD]

I hear ya. Mine does the same thing. I'll blow two or three in a row, then it will be fine for 6 months or a year.

 

[tkcomer]

Well crap. Tractor was doing fine until yesterday. Drove it to the house for dinner and then it promptly blew 3 10 amp fuses in a row. So I stuck the 20 amp back in to get it started and finish what I was doing. I sure wish I knew just what is blowing these fuses.

 

[MikePA]

Bummer. But with a 20 amp fuse in there, I imagine you're going to find out what's causing it. If the fuse doesn't blow, something else will.

 

[dqdave1]

'If you blow a 20 amp fuse , I would then begin to resolve the issue.

 

[jinman]

Bummer. But with a 20 amp fuse in there, I imagine you're going to find out what's causing it. If the fuse doesn't blow, something else will.

I agree with Mike. That's a dangerous way to "troubleshoot" this problem. You might end up burning up more than the faulty item; like wiring or switches. When you have a 10 amp fuse blowing is the the perfect time to troubleshoot the problem. You can start with a fistfull of 10 amp fuses and then start disconnecting circuits until the problem goes away and then work backwards. It would also be a great time to invest in a replacement circuit breaker so you can disconnect and reset repeatedly until you find the problem.

You don't get any work done while troubleshooting, but you may lose a lot of work time if you burn up a wiring harness too. And besides, if you discover where this problem is, you will instantly become a TBN hero.

EDIT: Here is a quote from Spencer200 about a circuit breaker replacement available from New Holland:

The 7.5 amp fuse has been replaced with an 8.0 amp circuit breaker because of repeated failures. The circuit breaker part number is 86610928 dealer list price is $7.31 but should be covered under warranty by a good dealer.