I happen to notice my DC outlet (Cigar Lighter) is not working. Fuse pops to it when I turn the ignition on - all else is fine. My thought was I did something when I installed either the winch or auxiliary panel. I disconnected both of those and it still pops. So I am continuing to track it down but it occurred to me I am continually turning on the tractor to test the fuse (which starts the fuel pump) but not actually starting the tractor - is that a problem?
Tracking a Short
- Thread starter AndyM
- Start date
Unless it makes the glowplugs unhappy, I don't know that it would hurt anything.
One thing I've done to search for a short was to put a light bulb in place of the fuse. A regular single filament bulb would work well because it won't care about polarity and you can see the difference between a short and a more normal load. It'll be full bright with a short and more dim if there's a load somewhere.
All you need to do is follow wires and jiggle them till the light goes out. Could be a pinched wire, point of a screw into the insulation or a misadventure with a new splice
One thing I've done to search for a short was to put a light bulb in place of the fuse. A regular single filament bulb would work well because it won't care about polarity and you can see the difference between a short and a more normal load. It'll be full bright with a short and more dim if there's a load somewhere.
All you need to do is follow wires and jiggle them till the light goes out. Could be a pinched wire, point of a screw into the insulation or a misadventure with a new splice
Now that you KNOW it blows a fuse... do NOT waste more fuses.
One way to troubleshoot this is to connect a small 12V lightbulb where the fuse normally goes. ( The bulb will lite up as long as the short remains.... will go out when the short is removed. )
Once the bulb is inplace, you can start to troublehoot (disconnect things, wiggle wires...etc) while watching the bulb looking for it to go out.
EDIT: Whoops, it appears Mr CHIM has already mentioned this. (I always seem to be late to the party)
Geeze, and I just ordered 150 fuses.... Thanks for the idea guys. I will wire that up in the morning! Speaking of glow plugs, if they come on when the ignition is turned on I assume the light idea means the tractor is running? Wouldn't want to keep the glow plugs going for an extended period, right?
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i7win7
Well-known member
Equipment
BX2370, B2650 grapple, tree puller, trailer mover, 3 point hoist, mower, tiller
Should be able to pull glow plug fuse or unplug connector for glow plug.
Now, using math, a 12 watt lightbulb / 12 volts = 1 amp
A short will pull more than 1 amp and test lamp will be full power.
If test lamp is on headlight circuit (headlights need more than 1 amp), test lamp will burn bright and headlamp filaments will barely glow. This could confuse a novice trouble shooter looking for a short that may not exist. If headlight filaments didn't glow, short is before the headlight.
The test lamp is a useful tool for most shorts. In above examples, something wants more than 1 amp of power.
Now, using math, a 12 watt lightbulb / 12 volts = 1 amp
A short will pull more than 1 amp and test lamp will be full power.
If test lamp is on headlight circuit (headlights need more than 1 amp), test lamp will burn bright and headlamp filaments will barely glow. This could confuse a novice trouble shooter looking for a short that may not exist. If headlight filaments didn't glow, short is before the headlight.
The test lamp is a useful tool for most shorts. In above examples, something wants more than 1 amp of power.
So I have been trying the light bulb test to no avail. Connected the bulb to the feed side of the fuse and ground to battery. Lit right up and stayed solid. Wiggled every wire I could find - no change. (confirmed my harness and winch adds are not connected to anything). Pulled the DC outlet feed wires so it was not connected and test it for continuity (not sure why but it has it),
Then I thought maybe I had the bulb hook up wrong so fed the positive wire to the downstream side of the fuse and left the ground to battery. Wiggled a bunch of wire to no effect. Any other suggestions? I could just live without a dc outlet but I hate an electrical mystery.
Then I thought maybe I had the bulb hook up wrong so fed the positive wire to the downstream side of the fuse and left the ground to battery. Wiggled a bunch of wire to no effect. Any other suggestions? I could just live without a dc outlet but I hate an electrical mystery.
GreensvilleJay
Well-known member
Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
this.. Connected the bulb to the feed side of the fuse and ground to battery. Lit right up and stayed solid.
wrong connection...
wire the bulb as if it WAS the fuse. the 'cheat' is to use a BLOWN fuse. fold the light bulb wires over the fuses tabs, then insert fuse(and wires) into the fuse holder.
when you apply power, if the light bulb lights up, you've got a short. trace wherever that wire goes. when the light bulb goes out ,you've found the trouble.
wrong connection...
wire the bulb as if it WAS the fuse. the 'cheat' is to use a BLOWN fuse. fold the light bulb wires over the fuses tabs, then insert fuse(and wires) into the fuse holder.
when you apply power, if the light bulb lights up, you've got a short. trace wherever that wire goes. when the light bulb goes out ,you've found the trouble.
dvcochran
Active member
Equipment
Kubota M9000, New Holland TN90, Deere 2640, Vermeer 504N, Vermeer 504SI, more
Is it an actual lighter or just a power source? It wasn't all that uncommon for the coil to the actual lighter (the part you hold) to get gummed up and cause an amperage higher than the fuse rating all the time. If it is an actual lighter a simple test is to just take the coil out and see if the fuse blows. If the fuse is blown or removed and the coil is Not inserted you should get a near infinite open reading on a meter. Anything else would indicate the wire is shorted somewhere. In other words, make sure you are only testing the wire with a meter and not some other load. If you don't have a meter the light bulb way works but only if it is shorted to another source of power, not if it is shorted to ground, which sounds like what you may have caused during re-assembly.
It just depends on what you have and what you are used to.
It just depends on what you have and what you are used to.
Just a power source, no lighter (my age and old habits are showing). At this point I have not reassembled anything (my adds are undone, the power plug remains unconnected). The power plug has been used once a long time ago to plug in an mp3 player.
I will have to think about your comment on a ground short vs shorted to another source of power. Looking at the wiring diagram it appears to my untrained eye there is nothing else on this fuse But the plug. It's not clear to me how any other wiring can even affect it.
One thought occurred to me - does it make sense for the power plug wires to have continuity with no fuse in place? Is it possible it's That wire that's shorting?
I will have to think about your comment on a ground short vs shorted to another source of power. Looking at the wiring diagram it appears to my untrained eye there is nothing else on this fuse But the plug. It's not clear to me how any other wiring can even affect it.
One thought occurred to me - does it make sense for the power plug wires to have continuity with no fuse in place? Is it possible it's That wire that's shorting?
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Buy a multimeter with a continuity tester and start tracing the circuit backwards. Don't be afraid to disconnect harnesses to help isolate the problem.
BX'r
Thanks - I thought that odd. No the plug is detached from the harness at present and the fuse still blows. Gives me an avenue to pursue.
Mikeester
I have mutiltimeters (analog and digital) - not sure I could tell which harness was at issue. If the power is on I would expect pretty much all the harnesses would have power - I am beginning to think the line to the plug is at issue - if it's drawing power when nothing is attached I think I will have my answer, yes?
Thanks - I thought that odd. No the plug is detached from the harness at present and the fuse still blows. Gives me an avenue to pursue.
Mikeester
I have mutiltimeters (analog and digital) - not sure I could tell which harness was at issue. If the power is on I would expect pretty much all the harnesses would have power - I am beginning to think the line to the plug is at issue - if it's drawing power when nothing is attached I think I will have my answer, yes?
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dvcochran
Active member
Equipment
Kubota M9000, New Holland TN90, Deere 2640, Vermeer 504N, Vermeer 504SI, more
Checking continuity in a wire has nothing to do with what it is connected to. It actually makes troubleshooting the problem more difficult when you do not isolate things. Continuity is simply testing the resistance of something, like a wire. Each wire size has a stated resistance. For example 12 gauge copper wire has a resistance of 1.588 ohms per 1,000 feet. Very low and depending on the quality of your meter it may read near 0.
Yes, if your meter is a clamp style that will measure amperage down pretty low that would be a good test but especially on a DC circuit reading voltage is usually sufficient.
dvcochran
Active member
Equipment
Kubota M9000, New Holland TN90, Deere 2640, Vermeer 504N, Vermeer 504SI, more
I think you mentioned the problem started after you did some reassembly? Is it possible you have some wires pinched together? I have even seen voltage bleed between two wires with insulation intact that were pinched together really hard.
Is there the possibility of someone having patched in wiring that is not on the drawings?
Yes on the continuity question. And voltage on a wire when checking continuity can do some weird stuff so better for the fuse to be blown or not there at all. That is also a real quick way to fry an analog meter or cheap DVM.
If you are checking just the wire, which is the preferred method, you should have good continuity.
Ok - sounds like you know a lot more about this than I do. My theory was to check if the wire in question had it's original integrity (no breaks). When the multimeter indicated continuity between the "plus" and "negitive" when there was no logical reason I could think of, I concluded perhaps it's an indicator of a problem.
No stray patches - I bought it new.
I did some more testing today and really solved nothing. I would like to have a closer look at the wire feeding the socket (it's still my prime suspect), but short of tearing the tractor apart I see no way of getting at it.
Not sure I know what you mean about the reassembly. I discovered this when I was testing a different issue and thought it might be related to a some mods (added fuse panel and winch) a while back. I had disconnected those mods to see if I had done something but they don't seem to have any connection (pun) to this issue..
So, I will ponder some more and welcome any suggestions but suspect I may have to live with no socket (which in my case is no real loss) until the day comes to do a serious tractor tear down.
No stray patches - I bought it new.
I did some more testing today and really solved nothing. I would like to have a closer look at the wire feeding the socket (it's still my prime suspect), but short of tearing the tractor apart I see no way of getting at it.
Not sure I know what you mean about the reassembly. I discovered this when I was testing a different issue and thought it might be related to a some mods (added fuse panel and winch) a while back. I had disconnected those mods to see if I had done something but they don't seem to have any connection (pun) to this issue..
So, I will ponder some more and welcome any suggestions but suspect I may have to live with no socket (which in my case is no real loss) until the day comes to do a serious tractor tear down.
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Your tractor frame is common ground. So if you use your continuity tester check for continuity at your DC outlet positive lead to ground. Note the wire color code and gauge. If you are blowing fuses then you have a short on that line and your continuity tester will indicate that to you.
Disconnect the power lead and test for continuity from the DC outlet positive lead to the shell. If you have continuity then that's your problem.
If no continuity then trace that wire color back to the next wire harness clip. Disconnect the wire harness clip and test your wire between the harness clip leading to the DC outlet. Have continuity? Your problem is in that wire. No continuity? Check backwards and repeat the process until you isolate where the short is occurring.
If you have your owners manual there will be an electrical schematic that will help you trace your wires and connections by color code and wire gauge.
dvcochran
Active member
Equipment
Kubota M9000, New Holland TN90, Deere 2640, Vermeer 504N, Vermeer 504SI, more
I stand corrected on the reassembly. I will blame that on my feeble memory.
Try this. Take your meter and clamp one lead to the bezel of the lighter outlet. Touch the other lead to a good ground or battery negative. Set the meter to continuity. The bezel Should be grounded and show strong continuity on the meter. Leave the lead connected to the bezel and take the other lead to the fuse panel and check the wire where it connects to the fuse panel. If it is still showing continuity you have a short to ground.
It still sounds like you need to physically trace the wire and check the socket connection.
Wonderful place this OTT - thank you all for some new ideas and leads. I will give them a whirl and report back.