5A Panel OPC Fuse Blowing

[Sharryn]

I was loading some manure from the pasture when my B3350 just quit and wouldn't restart. I found out that the 5 amp Panel OPC fuse had blown. I replaced the fuse and parked the tractor because it was getting dark. The next day I used it for probably about an hour, then it did the same thing. I replaced the fuse this time and it blew after going about 20 feet, so I replaced it for the third time and got it back to the shed.

I've searched high and low to find the answer to this problem on the forum and maybe I'm just searching the wrong way, but haven't had much luck. I know that this fuse is for the operator protection circuit, which I think means a safety switch or a chewed/bare wire.

Now my question. How do I find where the problem is located? I don't know how to use an amp meter. I know more about mechanics than the typical woman, but nothing near what you fellas would know. Oh, and it seems to only blow once the tractor is fully warmed up. That may or may not have anything to do with it, but I thought I'd mention it anyway.

 

[Roadworthy]

There is no magic solution for something like this. You may have a location where a rodent has chewed a wire in some nearly inaccessible location. The wire may still be intact but a bit of insulation is missing allowing it to short to ground. That's when the fuse blows. Try areas out of sight below the clutch, PTO, seat switch, and areas like that. After the wires leave the switch they usually go into some kind of sheath. A sharp eye and attention to detail will probably solve your problem. All an ammeter would do is tell you when you exceeded the current limit - and the fuse is already telling you that. Of course you could just put in a much heavier fuse and see where the smoke comes from. (No, don't do that.)

 

[Dave_eng]

I have attached two wiring diagrams for the B3350 OPC circuit.

Different models of B3350 have slightly different wiring.

In each, there are three 5 amp fuses associated with the OPC so if you could try and clarify which fuse of the three is blowing it would help narrow down where to look.

Dave

 

[D2Cat]

Sharryn, you can get a resetable fuse at your local auto parts or on line that may save you some grief while you determine where the problem it. One fuse, at about 7-10 dollars and when the fuse pops it resets itself so you don't have to keep buying fuses.

Similar to this. Be sure to get the correct size so spade terminals fit the socket. Take your burnt fuse with you if you shop local.

https://www.amazon.com/ZOOKOTO-12V-...S5WJXM6XDGP&psc=1&refRID=KTYFTRQ01S5WJXM6XDGP

 

[Sharryn]

You guys are ACES! Thank you! I will get a resettable fuse and also track down the wiring.

I found a mouse nest behind the fuel tank this evening, so I'm leaning toward a chewed wire somewhere.

 

[2Huskies]

There's also a possibility that the HST pedal switch is bad. At least that's what was causing the OPC fuse on my B3000 to blow.

 

[lugbolt]

I've had to replace a couple PTO safety switches for this exact issue. But it "could" be one of several other switches too.

 

[Russell King]

Since you said it happens when it “warms up” you should look first at where the wires are near and above things that get warm. The wire may be slightly above something that expands and then touches the bare wire, or the wires may soften with heat enough to sag and short.


Sent from my iPad using Tapatalk

 

[rkidd]

Very good chance it its the hst switch as someone else said. Happened to me on my B2650, and when I posted my results of replacing switch and it taking care of the problem, several other members had the same problem. There are steps to check all of the safety switches in the wsm.

 

[blenderbender]

Very good chance it its the hst switch as someone else said. Happened to me on my B2650, and when I posted my results of replacing switch and it taking care of the problem, several other members had the same problem. There are steps to check all of the safety switches in the wsm.

I have the same issue on my B3000. you referred to "wsm"..... what exactly is that?

 

[off-grid]

Same thing happened to my Blue Holland tractor...I kept replacing the 5 fuse then one time it went out in middle of my bamboo forest ..just wanted to get it back to house so I tried to go before tractor had cooled down..well it cranked but then started smoking from under tractor behind seat....I turned key off..got down to see what was goin on.... it was kinda burning..a little and smoking..I threw water on it and stood there looking at it wondering what to do when all of a sudden it cranked up...by itself!..I checked to make sure
key was off..it was..then smoking started from fuse box..then it went dead ...for real dead....now it sits under a tarp in the middle of the bamboo as i save up money for the $600 part...the mechanic helping me says,like others here, it had to do with a wire...we didn't know which one til the "incident"...now know it was the seat sensor which i had disengaged 10 years ago but if It hadn't been disengaged the tractor woudn't have started by itself..so...there ya go...long post but don't want my mistake to be repeated...much luck to you

 

[lugbolt]

check the neutral switch. Also check the pto switch. Have had issues out of both, they'll both cause 5A fuse to fail. IIRC I just pulled on the pto switch and it fell apart in my hand.