TG1860 Unit Relay and electrical question

[gc1289sg]

Well, I got in a hurry and did something very careless when jumping my kubota. Yes, i crossed the jumper cables. I have a kubota TG1860 lawn tractor and was performing some routine maintenance. After realizing what I did, now the mower has no lights or ignition. My first thought is that I blew a fuse or relay. This unit only has 4 fuses and 2 relays that I see on the parts diagram. My question is, what does the "Unit Relay" control? This is an $85 part that sets next to the "Controller Unit" which is a $897 part. Not really excited about replacing either part but I would rather replace an $85 part if that's the failed unit. I have not pulled it or tested the relay yet because its located in a very difficult area to get to. I will need to disassemble some of the mower in order to get to these part. Also, is there a way to test the "Controller Unit"? Any help would be appreciated. Thanks in advance.

 

[100 td]

Without seeing the circuit diagram...........it's hard to diagnose. However most kubota "tractors" at least have a fusible link/slow blow fuse in the circuit that powers the IGN switch. So check for a smaller wire going from your battery to the IGN switch or smaller wire from the main start solenoid going to your IGN switch and see if there is a fuse in line. The wire will be under the same terminal as the main supply from the battery.

 

[gc1289sg]

I did see the "Slow Burn" fuse and checked it. It's next to the starter solenoid but does not appear to be blown. I will check with my multimeter to make sure it has continuity. Thanks for the reply

 

[100 td]

So what voltage are you measuring, from the main power cable on the starter solenoid terminal, to a ground point ion the engine?

 

[gc1289sg]

Okay, you were correct with your first assumption. The slow burn fuse is in fact blown. It blew on the side so I couldn't really see it through the top window of the fuse because it is very dirty and cloudy. Hopefully the fuse blew before I had a chance to damage anything else. Thank you for your help!