mrharris12 32 #1 Posted November 29, 2023 Hi all, I have a 418-C and whenever I turn the light switch on in roughly 10 seconds the fuse 15A blows out on it (thats the Amp fuse that should be in according to the diagrams I have). Im assuming it has the factory headlights which are halogen 12v, if so wouldnt turning the lights on blow the fuse since the two headlights and back lights be more than the 15 amps that fuse can handle? Im not 100% positive if those are the factory lights are not (I am the second owner), and have not tried to disconnect the headlights when turning the switch on which I will do next but came here to confirm what I have is correct. 1 Share this post Link to post Share on other sites
ri702bill 8,316 #2 Posted November 29, 2023 As @squonk will confirm, it MAY very well be a problem with a bulb itself. Ten seconds is way too long for a fuse to go with a wiring direct to ground short. 2 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,040 #3 Posted November 29, 2023 What is the halogen bulb number you have? Standard bulbs are 35 watt so about 3 amps each. 2 Share this post Link to post Share on other sites
mrharris12 32 #4 Posted November 29, 2023 the front headlights are GE H7610 they are 12v 50w Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,040 #5 Posted November 29, 2023 49 minutes ago, mrharris12 said: the front headlights are GE H7610 they are 12v 50w So 2 of them will draw about 8.5 amps. 1 1 Share this post Link to post Share on other sites
mrharris12 32 #6 Posted November 29, 2023 so it sounds there is nothing wrong with the lights. Because I am assuming the back lights draw much less Share this post Link to post Share on other sites
JoeM 7,873 #7 Posted November 29, 2023 Some things i have found. Try bypassing the switch. Those will go internally bad from time to time. I have gotten some fuses that were knock off and they would blow way below the rating. Should actually check the wiring for resistance to ground. 2 1 Share this post Link to post Share on other sites
squonk 41,071 #8 Posted November 29, 2023 I have seen fuses blow instantly and some not blow until you exceed the rating by about 5 amps. My best guess is: A you have a wire in the circuit that has a tiny nick in it and it's a small short to ground slightly elevating the amp draw. Or B a bad bulb. You really need a DC Ammeter connected to the circuit itself and measure the amp draw on each bulb individually. If the amps are the same and equal and draw 4 amps apiece the problem is in the wiring or the rear lights. The wire to the rear is known to get chafed on just about every tractor so check that wire where it passes thru panels. If the wire is in a plastic split loom check it good because I have seen the loom itself cut thru wires. 2 2 Share this post Link to post Share on other sites
mrharris12 32 #9 Posted November 29, 2023 I disconnected the front headlights and removed the back bulbs and had continuity from the switch to ground with the switch being turned off. So I definitely have a short to ground somewhere. I taped a spot from before that runs over the steering but it might be the wire going to the rear lights, I have looked there at all honestly 4 Share this post Link to post Share on other sites
953 nut 55,194 #10 Posted November 30, 2023 3 hours ago, JoeM said: Try bypassing the switch. Those will go internally bad from time to time. 1 hour ago, mrharris12 said: continuity from the switch to ground with the switch being turned off. I think @JoeM already answered your problem. Can't hurt to check the rest of the wiring but neither side of your switch should have continuity to ground with the lamps removed. 2 Share this post Link to post Share on other sites
WHX?? 48,815 #11 Posted November 30, 2023 Lots of time ther can be chaffing on the wiring under the fender pan to the rear lights. I suspect my FEL 520 has that issue. It doesn’t blow till I get rumbling around on her. 4 Share this post Link to post Share on other sites
squonk 41,071 #12 Posted November 30, 2023 8 minutes ago, WHX?? said: Lots of time ther can be chaffing on the wiring under the fender pan to the rear lights. I suspect my FEL 520 has that issue. It doesn’t blow till I get rumbling around on her. Quit eating beans and frank's before you use tractor! 3 Share this post Link to post Share on other sites
WHX?? 48,815 #13 Posted November 30, 2023 2 hours ago, squonk said: Quit eating beans and frank's before you use tractor! Yah but @rjg854 says you like the smeĺl... I dunno that's what he says ! 1 Share this post Link to post Share on other sites
rjg854 11,360 #14 Posted November 30, 2023 I dunno about all that there How'd I get brought into this? 3 Share this post Link to post Share on other sites
mrharris12 32 #15 Posted November 30, 2023 15 hours ago, 953 nut said: I think @JoeM already answered your problem. Can't hurt to check the rest of the wiring but neither side of your switch should have continuity to ground with the lamps removed. yeah I think there is a small crack in the wire insulation that is running to the rear lights as Squonk mentioned. Now just have to take it a part a little and see what I see Share this post Link to post Share on other sites
peter lena 8,610 #16 Posted November 30, 2023 @mrharris12 wire chaffing , corrosion , cracked connections etc. , are standard stuff , have any alligator clip test wires ? that last horse I did , with the grass packed / matted corrosion behind the dash was at the top of the class, for continued issues . also did a RE ROUTE WIRING LAYOUT once related problems found . like to add screw on wire looms , and use wire wrap , in layout . most important is verify as you go , test / retest every gain , would also enhance grounding , long setting , original set up , like bolt on electrical connections , clean metal , dielectric grease . also a good time to , add a ground wire from battery ground bolt , to engine , RECTIFIER , never count on existing engine tins to carry a ground . amp gauge wakes up . Pete Share this post Link to post Share on other sites
