Blowing Fuse for Lights

[praxeum]

A couple days after the time changed I needed the lights on my 2014 CK3510HST for the first time in months, but they wouldn't work due to a blown fuse. I replaced the fuse and they worked fine. Until the next time I needed them when the fuse was blown again.

Yesterday I brought it in the shop and changed the fuse (a third time) then went searching for a chafed wire or something else that might be causing the issue. I could not find anything, so I connected a battery charger, turned the key to on and turned on the lights. Then I went around wiggling the wires seeing if I could find the problem area, following every wire from where it terminated at a light, through any clips or brackets for as far as I could, wiggling all along the way and the lights stayed on the entire time. I put a meter on the positive wire at each of the lights and tested for continuity to ground and there was nothing. I tried blinkers, brakes, anything I could think of to get it to blow and nothing, the lights stayed on through all of the troubleshooting.

I disconnected the battery fired it up and pulled it out of the shop and tried the lights and sure enough, the fuses was blown. I changed the fuse with the engine running, turned the lights on and off multiple times, stopped and started the engine a few times and the lights stayed working.

I'll desperately need the lights when the snow starts flying so any ideas or suggestions would be appreciated...

 

[Roadworthy]

A really basic suggestion would be check to see what the rating of that fuse should be and ensure you replace it with that value. It is possible the wrong value of fuse is in that location and you're replacing it with what was there. You could try removing all bulbs and operating during daylight hours with the switch on. If the fuse blows you'll then know it was in either the wiring or the switch. Sometimes mice will chew wires in very hard to see places. I wish you luck. An intermittent problem is the most difficult to track down.

 

[Diggin It]

The fact that it only seems to happen the way you describe is odd. Almost like a surge issue. Have you replaced or added any auxiliary lights, or is everything factory? Can you tell if the lights try to come on at all before the fuse goes? Or are you saying the fuse is gone before you hit the switch?

 

[Agvg]

Does it still blows if you disconnected the lights? Checked in side of the lights? Bulbs etc?

 

[VictorW]

As mentioned by Agvg, check all the bulb sockets. Maybe corrosion and the power goes to ground within the socket or a burnt socket itself.

 

[praxeum]

Thank you all for the suggestions, I really wanted to get to this today but life got in the way. The wife is headed out of town on Wed so I should have plenty of time while she is gone to look at it.

@roadworthy I can confirm the fuse is the right size, I am a stickler on those sorts of things. 10 amp is what is called for and that is what is in there. I will remove all the bulbs and run it to see what happens.

@diggin it The couple times I have tried to turn them on and found the fuse blown there was no momentary flash of the lights, they were just dead, so either the fuse blew while they were off or it blew so quickly they did not even have time to flash. There is one auxiliary light I added, on these Kioti's there are 12 VDC leads that come up next to the driver seat, I have a switch connected to the positive wire there that runs to a relay that powers the lights. The first thing I did was disconnect that (I assumed it was my install that was causing the problem) but even with that disconnected it still happened. But even with it, none of my wiring is live unless I flip the switch, and the fuse has blown with that switch off...so I don't think it is there...but I thoroughly inspected the auxiliary wiring when I inspected everything else and had that light connected and on when i was going through wiggling all the wiring trying to get it to blow.

@agvg @VictorW - thanks for the suggestion. I did not inspect the bulb sockets, that will be one of the first things I do when I get back to this.

 

[dlctcg]

Definitely check the bulb sockets... so not tractor related I did have a very similar issue with our Jeep, we checked everything to do with the wiring.... it turned out to be the switch. It was a random issue just like your... tested everything, then bypassed the switch & it just worked. We installed a new switch & it has been right ever since.... just something to keep your eye on...

 

[Doofy]

In years past, I would swap out the glass fuses with a circuit breaker with the same rating. This would allow me to work until the problem could be found.

 

[radios1]

one thing is, if the fuse holder is corroded or dirty, it could give you a high resistance connection which heats up the fuse until it blows. lights should have a self resetting circuit breaker anyway, it's dangerous without lights. cars switched over years ago to self resetting circuit breakers for the headlights..

 

[praxeum]

I've checked the fuse holder and it is clean as new, no corrosion or any dirt in there. I spent an hour last night and another hour or so tonight, took the bulbs out and drove around a bit and the fuse didn't blow so I put them back in and guess what? The fuse still didn't blow... There is no smoking gun yet but since the fuse hasn't blown again it's hard to know if the problem is still there or if I unknowingly fixed it. :confused3:

I'll bet the first time I go out to plow snow after dark it'll blow the fuse and leave me in the dark.