Engine fuse keeps blowing

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sscruggs

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Feb 9, 2005
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My Bobcat 863 was running great, used it recently for about an hour, got out and left it idling and a few minutes later it died. I went to start it and there was no electrical. Checked the fuses and the engine fuse was blown. Replaced the fuse, cranked the engine and the fuse blew again. Tried a couple of fuses with the same result. I think there is a short somewhere but it is not obvious. I lifted the cab and looked for any obvious wire problems but could not see any. Any advice would be greatly appreciated.
 

Fishfiles

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I would look to the fuel run/kill solinoid and the wiring to it as the most probable , then maybe the alternator , locating a short can be tough , there are special tools to find shorts but they are expensive , I would disconnect a plug at a time and put in a new fuse till the fuse doesn't blow any more than you will know the short is on that wire lead
 

Butters

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I would look to the fuel run/kill solinoid and the wiring to it as the most probable , then maybe the alternator , locating a short can be tough , there are special tools to find shorts but they are expensive , I would disconnect a plug at a time and put in a new fuse till the fuse doesn't blow any more than you will know the short is on that wire lead
My 751 did that. The hour meter was shorting out. I was surprised it would be on the same cirucit. I had Bobcat come out and find it. I about pulled my hair out.
 

skidsteer.ca

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My 751 did that. The hour meter was shorting out. I was surprised it would be on the same cirucit. I had Bobcat come out and find it. I about pulled my hair out.
You need to isolate the circuit its on by disconecting things one at a time and trying it with a new fuse.
At least its not a short that comes and goes, those are the worst to find. Pull the paney out with the key switch in it and see how many wires hook to the post that goes "hot " when you switch the key on.
Unhook them all, then one at a time reconnect them through a 20 amp fuse and see which one blows the fuse. That will start you in the right direction.
Ken
 

bobbie-g

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You need to isolate the circuit its on by disconecting things one at a time and trying it with a new fuse.
At least its not a short that comes and goes, those are the worst to find. Pull the paney out with the key switch in it and see how many wires hook to the post that goes "hot " when you switch the key on.
Unhook them all, then one at a time reconnect them through a 20 amp fuse and see which one blows the fuse. That will start you in the right direction.
Ken
When I've had problems with blowing fuses, I've grabbed a circuit breaker, usually rated below the rating of the fuse that keeps blowing, and haywired that into the circuit in place of the fuse holder. That saved me lots of blowing/replacing fuses while tracking down the problem. ---Bob
 
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sscruggs

sscruggs

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My 751 did that. The hour meter was shorting out. I was surprised it would be on the same cirucit. I had Bobcat come out and find it. I about pulled my hair out.
I checked that yesterday after reading one of the posts about it. I pulled both wires from the hour meter and it continued to blow the fuse. Thanks for the info though.
 

skidsteer.ca

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I checked that yesterday after reading one of the posts about it. I pulled both wires from the hour meter and it continued to blow the fuse. Thanks for the info though.
Just by attempting to start you power up 2 separate sets of circuits, 1 when the key is turned to "on" the other when you turn it past on to "start"
Is the fuse ok in the run position, but blows when you turn the key to start? or does it blow as soon as you turn to run?
You need to think of ways to narrow it down.
Ken
 
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sscruggs

sscruggs

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Just by attempting to start you power up 2 separate sets of circuits, 1 when the key is turned to "on" the other when you turn it past on to "start"
Is the fuse ok in the run position, but blows when you turn the key to start? or does it blow as soon as you turn to run?
You need to think of ways to narrow it down.
Ken
The fuse does not blow when the key is turned on. The fuel gauge, ammeter come to life. I can turn the headlights on, the preheat can be engaged and I can manipulate the controls with the key in the on position but not started without blowing the fuse. When I start it, it either blows while starting or very shortly after starting. I have gotten it to start and run for a couple of seconds so that leads me to believe that it is not the starter.
 

skidsteer.ca

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The fuse does not blow when the key is turned on. The fuel gauge, ammeter come to life. I can turn the headlights on, the preheat can be engaged and I can manipulate the controls with the key in the on position but not started without blowing the fuse. When I start it, it either blows while starting or very shortly after starting. I have gotten it to start and run for a couple of seconds so that leads me to believe that it is not the starter.
Is this a G series (triangle shapped head lights, or a F series or older, rectangle shaped headlites 1998 on back, if its older does it have the boss guage package?
From what you describe it is either in the start side, or maybe a short in the alternator, some systems use a oil pressure switch to connect/disconect the alternator draw from the engine depending on if its running (ie off = no oil pressure = alternator disconnected, which might explain the fuse blowing seconds after start up) other systems use the key only.
So try unhooking the alternator wires and start it and see. If the fuse still blows, re connect the alt, replace the fuse.
Now turn the key to run and cross the solinoid on the starter to crank the engine and start it (have someone in the operators seat if you machine tends to creep, safety) see if the fuse blows when you do not use the key to cranks the engine.
Regards
Ken
 
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sscruggs

sscruggs

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Is this a G series (triangle shapped head lights, or a F series or older, rectangle shaped headlites 1998 on back, if its older does it have the boss guage package?
From what you describe it is either in the start side, or maybe a short in the alternator, some systems use a oil pressure switch to connect/disconect the alternator draw from the engine depending on if its running (ie off = no oil pressure = alternator disconnected, which might explain the fuse blowing seconds after start up) other systems use the key only.
So try unhooking the alternator wires and start it and see. If the fuse still blows, re connect the alt, replace the fuse.
Now turn the key to run and cross the solinoid on the starter to crank the engine and start it (have someone in the operators seat if you machine tends to creep, safety) see if the fuse blows when you do not use the key to cranks the engine.
Regards
Ken
This problem has been resolved by a dealer service tech. This is a 1999 F Series and does not have the Boss Gauge package. Turns out it was the Fuel Shut Off Solenoid. The mechanic knew right away what the problem was based on my description of the problem. It took him about ten minutes to get the solenoid off and it started right up. Cost me $635 for parts and labor. Glad to have it back running but feel a little violated with the cost. If anyone has similar problems I can get some digital pictures to post to show where the solenoid is (in front of the alternator). Thanks to all for the replies and suggestions.
 

Tazza

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This problem has been resolved by a dealer service tech. This is a 1999 F Series and does not have the Boss Gauge package. Turns out it was the Fuel Shut Off Solenoid. The mechanic knew right away what the problem was based on my description of the problem. It took him about ten minutes to get the solenoid off and it started right up. Cost me $635 for parts and labor. Glad to have it back running but feel a little violated with the cost. If anyone has similar problems I can get some digital pictures to post to show where the solenoid is (in front of the alternator). Thanks to all for the replies and suggestions.
That does seem a little high... I'm not sure what a genuine shut down solenoid costs but my aftermarket one cost me about $70 AUD. You would have had to pay for the "service tech" to come out who would probably charge at least 1 hour.
At least its working again!
 

skidsteer.ca

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That does seem a little high... I'm not sure what a genuine shut down solenoid costs but my aftermarket one cost me about $70 AUD. You would have had to pay for the "service tech" to come out who would probably charge at least 1 hour.
At least its working again!
IMG_0088.JPG

Does it look like the ones from the Kubota engines in the kubota engines in the 700 series bobcats?
 

skidsteer.ca

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Ken, the Duetz motor in the 863 is completely different.
I knew the oil cooled critter was its own breed, but I guess it has`a shutdown solinoid built into the injection pump?
not a manual shutoff converted to electric, like the kubota one I posted the picture of?
Just trying to learn something.
Ken
 
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