in our shop we replace the wiring harness in these cubs , they are known for this, this is one of the many reasons why we tell our customers to avoid cub tractors they do not hold up. This isn't a switch problem , there is a short in the harness thats why it blows at different times. They can range from 200-300 bucks

Before you run down and buy a wiring harness or two- think about the obvious of what came apart. We know the hood was off. I would inspect the headlight wire routing and ensure the sockets are in place. Look for wiring that the routing may have been changed etc. BTW- I believe these should have a 20 amp fuse in the holder.

I do not have the light bar on the machine at all, But I do have the wires taped that went to the sockets. Would you suggest that I start from those wires back to see if I have some kind of grounding problem? Again, did not do it before it went to shop. Wire harness could be next step I suspect if all else fails. I suspect 30 amp fuse will not cause any problems if a 20 was there originally, correct?

Apart from melting the wiring and possibly causing a potentially fatal fire, why not use a fuse with too high of a rating? The Gene Pool does need a little cleaning now & then!

According to my schematics, the light switch is part of the ignition switch. IF you are running with the lights OFF, there shouldn't be 12V on the lighting circuit.
IF you DO have 12V on that circuit with the lights off, you have a bad key switch. THAT could be shorting out intermittently and be difficult to trace. Got a voltmeter or 12V test light?

so you are saying that I should make sure that when I am running, that the switch is not turned on the light setting, if it is then check the light wire to see if I got juice (should) if it is off and I got juice, then it could be the ignition switch. Again, the light bar came off a while back since it broke, I put a new one on and as the plastic hold down points began to break off etc.. I just pulled the whole thing off and decided not to buy another light bar which got not use anyway (they are not cheap). I will continue to follow wiring back from lights to see any breaks etc.. I assume that I can always go the wire harness way (can get one that was pulled from a machine on the net for under 100 bucks if all else fails) I also guess that some years the harness had wiring for low oil only and other years for oil and amp reading but that a general 2135 harness will works plus or minus one or more light fittings on the dash.I just keep thinking it has got to be something simple. Any need to check wiring under the seat while I am at it?

Cub Cadet may have a schematic on line or maybe Bill can share a link. Replacing an entire harness is a lot of work and you still do not know if that is your problem. I've had a few wiring issues with Cubs, but there is no epidemic. BTW-some of these have 2 fuses- some have one. It is good to know in order to help isolate the circuits properly. Have you talked to the shop who did the work?

With the light switch OFF, there should not be ANY VOLTAGE on the wiring to the lights.

"I do not have the light bar on the machine at all, But I do have the wires taped that went to the sockets. "
AND
"I just pulled the whole thing off and decided not to buy another light bar which got not use anyway"

The fact you didn't mention the method of removal for the light bar, I didn't think you even had a lighting circuit. Instead, you have what could easily be a damaged lighting circuit! Different approach to troubleshooting with more accurate knowlwdge.

IF you don't get fuses blowing when keeping the key switch in the "no lights" position, obviously the problem is occurring when in the "lights on" position.
That would probably mean your "taped" wiring job is insufficient or you have a worn spot shorting to ground in the lighting circuit.

last bit of information. put volt meter on light wires (my harness also has an amp light) With key off- no power- with key on light setting 12.5 volts- with key in run position (no lights) .15 volts! I looked at all wiring from lights back and retaped. Tried to mow lawn (must have blown 10 fuses) so had to hand mow an acre (damn) So machine has two fuse holder that I see. The one that blows and stops blades (but keeps motor running since I do not turn key off just PTO- replace fuse- mow some- fuse blows- replace etc..Some times fuse blow when I insert it right away- sometimes not (PTO is off remember as I replace it) anyway. I blew last fuse- turn machine off- could not restart (I suspect that the fuse operates both ignition and PTO- take only good fuse left from other holder- start machine- put away- then it won't turn off! had to pull plug. Does all of this point towards the ignition switch?

I know I will be cut up and hung out to dry, but here
goes: Replace the fuse with a piece of copper tubing
and watch where the smoke comes from.

What's the serial # of the unit?
I've found 3 different schematics, but need the SN to pick the correct one.

When you got 15V, was the engine running?
IF NOT, there has to be something wrong with your meter, since battery voltage is only about 12.6V.

The fuse you "borrowed" is to the grounding system, which is used to kill the engine. No fuse, and the "kill" wire won't work.

IF the light switch is OFF, there should be NO voltage to the "L" (Lights)terminal of the key switch, and thus to the lighting wires!
Either the key switch is bad, or 12V is being shorted to the Lighting wires elsewhere.

The fuse you are blowing, is between the "B" (Battery) terminal of the key switch and the stud on the starter solenoid that also connects to the Battery + cable.
IF that wire isn't shorted to ground somewhere, THEN-

I would suspect the key switch is broken internally, with the contacts moving around and shorting to the "other" terminals on the switch, such as ground or lights.

bill, i read that as .15 volts, not 15 though it is hard to tell.

you know, i have always been told that the definition of crazy is repeatedly doing the same thing and expecting different results. quit sticking fuses in there and start ACTUALLY diagnosing the problem. and go back to teh correct size fuse.

i would not buy a new wiring harness unless the existing harness is extremely damaged. you cna splice a broken wire or even several, you can tape up and seal nicked wiring(don't use cheap tape get super 33), and you can ohm each individual wire if necessary to find breaks/shorts. this harness is not goign to have shielded wires nor fiber optics, therefor there is NO reason it cannot be fixed except for after the fire. and you keep putting bigger fuses in it and you will have one, that or you will eventually melt all the insulation off the wires and be forced to do a new harness.

i would remove the deck and go over/under/around the whole wiring harness. odds are you have 1 wire hanging close to somethign and it has a small nick. when it hits the chassis, it pops the fuse. heck, the shop could have even mashed it when installing the new engine.

052417 Fixed CC2130 that wouldn't convey any electric circuit except blow main 20 AMP fuse. Problem was: cheap, poor quality insulation headlamp wiring. Fixed via: isolating worn area, insulating it and restoring. Engine/mower now works beautifully. I bought my CC mower because it is made in America. Shame on them for using cheap quality parts.

CC=Cub Cadet model 2130 mower

I used very high quality silicone with adhesive tape to insulate wires.