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I experienced an electrical short 3 or 4 weeks ago, while running, that sent a jolt up the throttle cable and shut it down immediately. Since then, it will not turn over or start from the ignition switch; however, I can get it to turn over if I "hot wire" either the wiring harness that plugs into the ignition switch, or the starter solenoid posts, but even under either of those two circumstances, it will not fire, only turns over.

I have replaced the ignition switch and the pto/seat relay, and have tested all switches for continuity, and they all have continuity when they are supposed to, so I am thoroughly confused and have no idea what to look at or check next. Any help or guidance would be greatly appreciated.

Have you checked ALL the fuses and looked for fusable links ?
Where was this "short" ? If you can "hot wire" it at least one break in the circuit is probably between where it normally goes and where you jump to.
Sounds like you may have burned a solenoid - does the carb. have a solenoid wire to the fuel bowl ?
Have you pulled a plug to find out if it is getting spark ?

Just ideas -- hope something helps !

O2Man said:

I experienced an electrical short 3 or 4 weeks ago, while running, that sent a jolt up the throttle cable and shut it down immediately....

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Are you saying you 'felt' a "jolt up the throttle cable" ... if that is the case, the throttle cable is likely shorting out the high voltage spark plug cable... you will not feel 12 volts...
Check the spark plug wire... :smile:KennyV

well, I didn't actually "feel" anything, basically what happened is it was running just fine for a minute or two, then just abruptly quit and shut down as if I had turned the key off, but I hadn't, and then I looked back and saw a little bit of smoke coming from behind me, so I got off of the mower and went to see where it was coming from, and it was the plastic cover to the throttle cable melting. Other than that, it does not appear to have actually burned up anything, but I cannot get it to even turn over via the switch now, although the switch itself is brand new and tests out fine, and all of the safety switches that I have been able to find and test are also testing fine for continuity, etc. And I can get juice to the regulator (brown) wire at the harness when I "hot wire" it, but it is not getting power from the switch when connected.

I will check the plug wire, as that seems fairly easy to check. Would that prevent the ignition switch from giving voltage or power to where it needs to in order for it to turn the motor over and/or fire and start?

And one other question, do any of you know off hand where the brake switch is physically located on this rig? I have found it on the wiring diagram but cannot place it on the mower itself. That is the only safety switch I have not tested yet, as I was not aware of its existence or where it was to check it.

Thanks for any and all offers of help, I appreciate it

So you have 12 volts at the key switch?
If not check for a fusible link or fuse in the wiring that should supply the 12 volts... :smile:KennyV

Yea, I have 12V going to the switch and at the switch, that is what has me baffled. I have tested the wires at the harness where they connect to the switch, and the switch seperately for voltage and continuity, and both check out fine seperately; however, for some reason that I have not yet been able to figure out, I am not getting anything at all FROM the switch to the starter when the harness is plugged into the switch. I can "hot wire" the wiring harness and get it to turn over non-stop, and same for when I hold a screwdriver up to the bolts on the starter solenoid; but I can't get it to fire under any circumstance, and can't get it to do anything at all via the key switch.

I have checked all fuses and they are all good. I have checked all of the safety switch connections EXCEPT for the brake switch, because I have not been able to physically locate it yet. I have seen it on a wiring diagram, but cannot yet find it on the mower itself. All other safety switches have continuity when they are supposed to though, so if it isn't the brake switch that is keeping it from sending the charge and firing, then I have no idea what is going on with it, and it is probably going to the shop next.....

Best I can tell, all safety switches are making contact when they are supposed to. The seat switch is definitely making contact when sat on, and all safety switches that I know to engage are engaged when I try to start it, same as before the short when it would fire right up. I have not yet found the source of the short that shut it down, but I have thought about that, I figure I would want to find the source of the short and fix that specifically too, otherwise the potential is there for it to short out all over again even if I fix everything else (unless of course whatever it is that is keeping it from firing IS the source/cause of the short as well.) ??

If the throttle cable got hot, there must have been some electrical contact with it somewhere. Is there continuity NOW from cable to Positive battery terminal ?

If I had tried everything else, I might start checking continuity of every positive wire to ground {disconnect battery} (there should be no continuity from positive to ground). If you get a positive to ground continuity, that is your short.

BKBrown said:

If the throttle cable got hot, there must have been some electrical contact with it somewhere. Is there continuity NOW from cable to Positive battery terminal ?

If I had tried everything else, I might start checking continuity of every positive wire to ground {disconnect battery} (there should be no continuity from positive to ground). If you get a positive to ground continuity, that is your short.

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I did some testing tonight (not sure I did everything right, but I think I did). Here is what I did and what I got:

Using a voltage/ohm meter, I touched the red prong to the positive battery terminal, as well as to the pin on the starter solenoid where the brown wire plugs into (from the key switch), and the black prong to the throttle cable, and I got continuity both times. I don't know if I did that test right, and/or if that means I have continuity to the throttle cable, but the ohm meter did beep steadily when hooked up that way.

A couple of other things I noticed; When I tested the pins on the starter solenoid (with the black on the ground pin and the red on the brown wire pin), it had continuity all the time, both with the key switch turned off and on. The guy at the Gravely dealer told me that either meant my starter solenoid is bad or not bad, but I don't remember which one he told me.....

One other thing I checked is, I grounded the black wire on the voltage meter, and plugged the red one into the red&yellow wire that goes from the start relay to the fuel solenoid, and it had no continuity with the key on. Should it? I just wasn't sure if that was normal or not....

At this point I think I'm ready to just set it on fire and burn it to the ground, or take it to the local scrap metal place, have it weighed and see what they will pay me just to get it out of my yard and sight. I can't figure this damn thing out and hate to think what a shop would charge me to figure it out and then fix it. If it isn't going to start or run either way, no need for it to sit around and take up space... Ugh

See inserts in quote.

O2Man said:

I did some testing tonight (not sure I did everything right, but I think I did). Here is what I did and what I got:

Using a voltage/ohm meter, I touched the red prong to the positive battery terminal, as well as to the pin on the starter solenoid where the brown wire plugs into (from the key switch), and the black prong to the throttle cable, and I got continuity both times. I don't know if I did that test right, and/or if that means I have continuity to the throttle cable, but the ohm meter did beep steadily when hooked up that way. If you got continuity from positive battery terminal to throttle cable - I would say you have a direct short to that cable -- if that cable touches ground anywhere, I would think it would short out your battery -- disconnect that battery until you find the short !
I would need to see the wiring diagram, but I can't think of ANY reason the throttle cable should have continuity to the positive battery terminal. Unless it is a positive ground system (I doubt that) !

A couple of other things I noticed; When I tested the pins on the starter solenoid (with the black on the ground pin and the red on the brown wire pin), it had continuity all the time, both with the key switch turned off and on. The guy at the Gravely dealer told me that either meant my starter solenoid is bad or not bad, but I don't remember which one he told me.....

One other thing I checked is, I grounded the black wire on the voltage meter, and plugged the red one into the red&yellow wire that goes from the start relay to the fuel solenoid, and it had no continuity with the key on. Should it? I just wasn't sure if that was normal or not....

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If you have not fried your DVOM already you soon will... NEVER measure resistance continuity with power applied to the system... Like BKBrown said ... disconnect the battery at anytime you are measuring Ohms...

You can do a lot of trouble shooting, measuring voltages and voltage drops with the battery hooked up... but you will damage your meter if you are measuring continuity with power applied to the circuit... :smile:KennyV

Update: Have made some progress with the mower, but still not totally out of the woods or 100% normal...here's what I figured out today and what is going on now.

All along, my father-in-law suspected this piece that looks like a trailer plug type thing, #13 on the wiring diagram, a "Molded Diode plug". Well, when I took it into the mechanic at the local Ariens/Gravely dealer and told him where it hooked up to on the mower, etc, he told me that it didn't mean anything or do anything for my mower, that it was basically just a "filler" for where another wiring harness would normally plug in on other models, etc. Well, turns out that after figuring out one of the spots in that piece that apparently is supposed to have continuity or voltage but wasn't getting it, we kind of rigged it to where it would work, and *tada*, it starts and runs...sort of......

However, now it is doing a couple of things that aren't quite right and I'm not sure why. For one, the parking brake switch seems to be reversed now, meaning it will NOT start with the parking brake ENGAGED, but rather it will only start with the parking brake DISENGAGED....then, after starting right up and running AND mowing fine and well with the throttle set about midway (the little latch between slowest and full throttle), if I adjust the throttle down (to kick the idle down before shutting it down), it will sputter, die, AND blow the 30 amp fuse, but if I replace that 30A fuse and leave it running at that same throttle point, I can turn it off via the key and it doesn't effect the fuse at all, I can start it back up with no problem....

Any ideas what might cause what it has going on now? Could it be that molded diode plug just needs replaced altogether to make the proper connections and correct what it is doing, or do I still have wiring issues somewhere somehow??

Did you measure the diode forward & reverse to see if it is bad ?? :smile:KennyV

Glad you have made progress !
Just in case - a diode only allows current flow in one direction - if it is bad you will get current flowing back thru that wire. It is there for a reason and if it is bad, it needs to be replaced. The bad diode might explain reversed brake switch issue ? (I guess you did find the brake switch) I would probably just replace it if it is questionable.

Did you ever find out what caused the short to your throttle cable ?

BKBrown said:

Glad you have made progress !
Just in case - a diode only allows current flow in one direction - if it is bad you will get current flowing back thru that wire. It is there for a reason and if it is bad, it needs to be replaced. The bad diode might explain reversed brake switch issue ? (I guess you did find the brake switch) I would probably just replace it if it is questionable.

Did you ever find out what caused the short to your throttle cable ?

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I wondered about that...I went ahead and called my Ariens dealer this morning and ordered a new molded diode plug, it is only $15 and we have figured out at this point that it is definitely part of the problem, if not THE whole problem. And if it being bad could cause the current flow to be opposite, that very well could explain the parking brake being reversed. Yes we did find the brake switch, it is actually on the underside of the frame below the engine area. We tested it and the switch itself appears to be fine, so I'm thinking that diode plug has thrown the brake's operation off. Still not sure what is causing it to blow that 30A fuse when I adjust the throttle downward, but I'm wondering if that too might have something to do with the connections to that diode plug being off? I have not found out directly what caused the short to the throttle cable, but the rig did run very well for the time I ran it last night (30-45 minutes) and it had no issues whatsoever with anything getting hot or shorting; only issues were these 2 things I mentioned, the brake seeming to be reversed, and it blowing that fuse when I reduce the throttle.....Hoping the new diode plug will fix both of those issues, then I'll be back in business totally!!

KennyV said:

Did you measure the diode forward & reverse to see if it is bad ?? :smile:KennyV

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Hey Kenny, I had not tested the diode, mainly because I did not know there was a way to or how to; my father-in-law suspected that piece from the beginning but he was not sure either exactly what it was or if it was supposed to have current, etc. etc. I am guessing though by what the mower is doing now, that it must be bad or off, and it is fairly cheap, so I am just going to get a brand new one and swap it out, see if that will solve at least some if not all of my problems. My plug should be in Wednesday or Thursday (Ariens dealer had to order it), so I will update you guys on what it does after I switch it out!!

I went out and tinkered with it a little more after work tonight, and noticed more issues with the throttle than what I found last night. When I move the throttle up, the idle slows down rather than speeding up, and within seconds, it dies and most of the time blows that 30A fuse. So basically what I experienced last night when moving the throttle downward, it does the same thing when I try to kick the throttle up.

So my question is, is it possible that the diode being bad could also cause this, and a new diode (ordered) will most likely fix all issues I am having? Or have any of you heard of this and is this issue seperate from the diode or something the diode won't fix??

The Diode will probably solve some problems, but I still believe (somehow) this is connected to the original "short" that made the throttle cable hot and melt the cover.
If it truly was a short, there must have been a wire somewhere that came in contact with the throttle cable. Is that part of the cable anywhere near the exhaust ? If this is a normal throttle cable there is a metal push/pull wire that is inside a spring conduit (should be constant continuity from wire to spring) I can't figure out how it could get hot in only one spot unless there is not normally full continuity and positive touched ground somewhere in that cable. ????? :confused2: I might (at this point) take the throttle cable completely off and inspect it from one end to the other.
Something is shorting somewhere that blows that fuse !

Well, at this point, I have replaced the diode plug with a brand new one, and once again it will not turn over or crank at the ignition switch AT ALL. Still turns over good and strong all day with metal touched to the contacts on the starter solenoid, but not putting any fire to the switch or starting in any way. So at this point, I am completely and totally lost and have no idea where or what to even check next...Ugh...I can't help but think it is something fairly simple, but I hate having no idea what it possibly could be or where to even look next in the troubleshooting process to try and fnind out..... :confused2:

I'm guessing that you have disconnected the battery and checked the continuity of each of the wires that is involved in the circuits to key switch and starter.

Have you also checked continuity to ground for each of those wires that should not go to ground ? There may be one of those wires that shows continuity to it's intended contacts, but also is grounding out somewhere.

SOMETHING caused a short that made that throttle cable hot. :confused2:
SOMETHING is not allowing the circuit to connect normally to the starter. :confused2:

I wish I could see the machine myself -- at this point, I might just start replacing wires with new ones and new switches etc.

You deserve credit for not giving up ! :thumbsup:

GOOD LUCK !