this problem is with a 2003 new Holland ls180. let me start from the beginning. a few months ago I laid on my horn button and the horn stopped working. within a few days I experienced engine shut down. I checked the fuse panel and it was my eic fuse. replaced and good to go, well so I thought it has continuously blown fuses since. I went over the wiring with a fine tooth comb and cant find any breaks or melted wires. well then my starter keep turning over even after the key was not in the start position. I replaced the starter solenoid thinking that was my problem. no luck so I pulled the solenoid ignition wire after starting and the starter stops. at this point I still have no horn and the fuse is good and the eic fuse is only blowing here and there. I cant seem to find the problem. I checked the ignition wire at the solenoid and test light indicates no power when the key is just in the run position. seat switch and seat belt switch seem to be fine control panel lights up when in the seat. I turn the key to start and my problem begins. when it does blow the eic fuse it will start in service mode. the only way I can get the starter to disengage is by pulling off the power from the battery or by pulling off the solenoid ignition wire. and this eic fuse blowing keeps happening when I hit a bump and it comes and goes. I am going to pull the accessory wire from the ignition switch to try and narrow it down. yes I replaced the ignition switch and starter solenoid but still have this unfindable problem somewhere in the wiring. the more I read the eic fuse blowing seems to be a common problem. I don't know if it's linked to my horn and starter issue, it may just be three isolated problems or might be all part of the same problem. can anyone give me some ideas on how to find the problem with the starter wanting to crank over even after engine starts and key switch is in run position. and also with why my eic fuse keeps blowing and why my horn wont work even with good fuse. thanks
Start with the starter. If the issue is intermittent it will take some time but be worth it. If you have a friend that would make life easier. Hook a DMM up to the S terminal on the starter and leave the wire connected. You should be able to get a good contact in there. Then go start and stop the engine until you can get it to stick. When it sticks see if there's voltage at the S terminal. If there is then the starter is fine. Next you need to check the start relay to see if it's sticking. It's in the engine fuse compartment. There will be two of them, the left one is for the starter and the right one is for the glow plugs. You need to hook the DMM up to the wire coming from the ignition switch that energized that relay. Then go make it stick again and when it does see if there is voltage there. If there is no voltage there then that relay is bad. If there is voltage then trace it back to the interlock relay to observe if it's sticking. If it's good then check the ignition switch. Start with that and see where it gets you.
You can test the horn with a jumper wire, its possible your switch or horn went bad due to a coincidence. I would also double check your grounds, raise the seat and you will see them attached to the bellhousing, follow them out from there and make sure all are clean. These machines are also known for bad battery cables.