# JD 2955 Blowing Fuses



## North Maine (Jul 1, 2011)

Can anyone here help me figure out what fuses are what on a JD 2955? This tractor uses this stupid "Fuse Card" system that has no explanation or diagram just a circuit card with fuses jammed in it. I have figured out that Fuse "5" is the main 12V supply for the rest of the fuses, but this is the fuse that keeps bursting! It only blows when I run lights AND the A/C on "++" or high. I can run either and never have an issue, but if I run both then I'm blacking the whole thing out.

I'm very close to completely removing the lighting from the board fuses and wiring it all up completely separately.


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## NDVA HAYMAN (Nov 24, 2009)

I would start with a wiring diagram from JD. If I have a problem with one of my tractors that I can't figure out, I will talk to a JD mechanic and ask them for info. They can usually get you in the right direction. Mike


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## North Maine (Jul 1, 2011)

Thanks, I have the I&T Service manual and while there is a bunch of wiring diagrams in there they are poorly labeled and not much help. Are the real JD diagrams better?


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## RockyHill (Apr 24, 2013)

Do you have the fuse diagram? This is from our OP manual. Looks like #1 has lights & AC. There is a new member that is a JD dealer that gave helpful advice on another topic maybe he can help.


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## Bazooka (Sep 17, 2013)

I would check the amps the a/c fan is drawing. It could be getting worn enough that on the ++ it is generating enough heat and drag to cause the fuse to fail, although it shouldn't be on the same circuit as the lights. Another thought... try operating fan & lights without the a/c on. If it doesn't blow then you've eliminated the fan and can focus on the lights.

Those german utility tractors are a little complicated with those fuse card/printed circuit systems. over time they have loose connections that can cause problems that will drive the best technicians crazy. Most tech's really don't like working on them.

good luck


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## somedevildawg (Jun 20, 2011)

North Maine, you determined that the fuse 5 is the "main" for the other fuses....what size is this fuse in relation to the other fuses in that circuit? In other words, what are the sizes of the fuses that are behind the fuse number 5? I would bet that the problem is in the a/c fan switch or the blower motor, but a process of elimination will be able to find the culprit....do you have access to a volt/ohm meter capable of measuring amperage of 20 amps or so.....even if you have one that does 10 amps it would be of help in diagnosing this problem....


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## mlappin (Jun 25, 2009)

Looking at picture #2 I'd say the switch gets it's juice to run the light relay from the same source as the A/C.

Bad brushes or dry bearings/bushings in the fan motor will certainly cause it to pull too much juice. That would be where I'd start as I've changed half a dozen blower motors over the years that were pulling a LOT more juice than the original (correct) fuse would handle.


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## North Maine (Jul 1, 2011)

Thanks for all your help and suggestions, I'll dig into it this evening I hope... Thank you very much for the fuse picture, no I do not have the OP manual and that is a major pain. I am confused a little by Fuse 5 being labeled "not used" when it has 12V all the time and can be clearly traced as the 12V supply to everything. Devildawg you asked a question that really has me perplexed so I'll put it out here for you to chew on... fuse 5 is 20 Amp. Every other fuse is 20 Amp or less, so I'm not sure how JD intended on the owner diagnosing anything since Fuse 5 always the fuse to blow.

I do have an amp meter and I'll try to get some readings on the blower motor and the AC compressor. Again thanks for the replies!


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## RockyHill (Apr 24, 2013)

BBOELLSTORFF said:


> I would check the amps the a/c fan is drawing. It could be getting worn enough that on the ++ it is generating enough heat and drag to cause the fuse to fail, although it shouldn't be on the same circuit as the lights. Another thought... try operating fan & lights without the a/c on. If it doesn't blow then you've eliminated the fan and can focus on the lights.
> 
> Those german utility tractors are a little complicated with those fuse card/printed circuit systems. over time they have loose connections that can cause problems that will drive the best technicians crazy. Most tech's really don't like working on them.
> 
> good luck


When we bought ours (used) usually had to slap the dash to get it started. Previous owner had put some kind of 'customized' starter that didn't work well either -- got rid of that. Can't remember if it was the cost or if the printed circuit thing could be replaced (fairly certain any cost would have been big influence  ) but Jeff took the printed board out and very tediously soldered (just melted the solder that was there) the connections and solved that problem -- hope saying that doesn't jinx it. Jeff read these posts this am and he was remembering using needle nose pliers to tighten up the way the fuse card fit where it was a bit loose and was blowing a fuse --couldn't remember which one. It didn't require any new parts (except the fuse of course), just getting all the details right.


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## somedevildawg (Jun 20, 2011)

North Maine said:


> Thanks for all your help and suggestions, I'll dig into it this evening I hope... Thank you very much for the fuse picture, no I do not have the OP manual and that is a major pain. I am confused a little by Fuse 5 being labeled "not used" when it has 12V all the time and can be clearly traced as the 12V supply to everything. Devildawg you asked a question that really has me perplexed so I'll put it out here for you to chew on... fuse 5 is 20 Amp. Every other fuse is 20 Amp or less, so I'm not sure how JD intended on the owner diagnosing anything since Fuse 5 always the fuse to blow.
> 
> I do have an amp meter and I'll try to get some readings on the blower motor and the AC compressor. Again thanks for the replies!


Ok....what I was getting at is the fact that someone could have replaced fuse number 5 with a fuse of a lesser rating at some point, most older tractors that I have seen have 20-25 amp max rating.....but it's easy to see that if the "main" is 20 and two devices are running (in this case blower motor, and lights) with one being a 10 amp draw and the other being 20 amp draw, you can see where a problem is going to happen, just because its fuse is rated for 20 amps doesn't mean that the device pulls 20 amps, in fact considerably less will be drawn, but in the event of a problem; such as burnished brushes or switch contacts, the device will pull more amperage than normal. But in the case of fuse number 5, if it were a 20 and several devices behind number 5 were 10, 15, 20 amp fuses, perhaps number 5 has been replaced by a fuse that will not handle the cummulative amperage draw. Using your meter will enable you to diagnose this problem very quickly, make sure to change the leads on your v/m to amperage before checking current draw.

I believe you'll find that the blower switch may be bad....but you could also have a blower motor drawing more than its fair share of amperage, especially since it happens only on high, that's a clear indication it's very likely to be the problem. I doubt very seriously that the lights have anything to do with this problem unless you find something fishy when reading light amperage. Also, a lot of manufactures used to use slow-blow fuses, especially common on a/c systems, where the current draw may spike initially close to the fuse rating but then draw a nominal amperage once operating.

Hope it helps


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## RockyHill (Apr 24, 2013)

North Maine said:


> Thanks for all your help and suggestions, I'll dig into it this evening I hope... Thank you very much for the fuse picture, no* I do not have the OP manual *and that is a major pain. I am confused a little by Fuse 5 being labeled "not used" when it has 12V all the time and can be clearly traced as the 12V supply to everything. Devildawg you asked a question that really has me perplexed so I'll put it out here for you to chew on... fuse 5 is 20 Amp. Every other fuse is 20 Amp or less, so I'm not sure how JD intended on the owner diagnosing anything since Fuse 5 always the fuse to blow.
> 
> I do have an amp meter and I'll try to get some readings on the blower motor and the AC compressor. Again thanks for the replies!


eBay has OP manual for $25 and service/tech manual for $70


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## North Maine (Jul 1, 2011)

Thanks again guys...

The card itself isn't too expensive... I just put a brand new one in actually because the old one burned up. I got to find out the hard way that the previous owner "solved" the fuse 5 problem by soldering a copper rod across the fuse terminal. When I smelled the card burning was when I found out I had a problem.


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## somedevildawg (Jun 20, 2011)

North Maine said:


> Thanks again guys...
> 
> The card itself isn't too expensive... I just put a brand new one in actually because the old one burned up. I got to find out the hard way that the previous owner "solved" the fuse 5 problem by soldering a copper rod across the fuse terminal. When I smelled the card burning was when I found out I had a problem.


Hate when that happens....used to be (and still is) if guys had a problem with a fuse blowing they would "smoke it out" to find the problem, i never subscribe to that theory.....have wrapped a few fuses in chewing gum wrapper to get home tho....desperate times....sounds like you are headed n the right direction, good luck


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