b3030 operator presence control harness question

[DiezNutz]

Seat switch (under seat): Yellow w/Red stripe and Red w/Black stripe
Tilt switch (front of seat): Blue w/Yellow stripe and Red w/Black stripe.

Since the pairs are in separate looms it would pretty hard to mix them up, so you must really torn some stuff up to do your testing.

Don't worry about the OPC until you put the Tilt switch back to the way it was, and jumpered the Seat switch like I suggested. Given the choice, you'd really only want to replace a bad Seat switch - right?

P.S. - I don't know what "scanned doc" you're talking about.

 

[Charlesaf3]

Thanks. Yeah, I have the messicks seat substitute, and I think there was a connection problem in it, so I tore it back past some splices. I should have marked it, but didn't, like a dummy.

I have the WSM chapter on the OPC as a PDF - generally good, but some of the drawings are blurry.

I'm starting to think the HST switch went. I tore down the panel and took apart the OPC to see how everything lines up. Question, though I'm going to crawly under the tractor to see if I can figure it out. The red/black wire is the power feed, right? Where does it come out of, do you know?

The OPC isn't in pairs, its in separate inputs - I figure they get their juice from a common source, and then it goes in through the switches to the OPC. Is that right?

 

[Charlesaf3]

so I just went and crawled underneath the tractor. That was fun, since its parked in the mud. Switches aren't so obvious... guess you have to take the top panel under the seat off to see things?

My thought was to jump the various connections going in to the opc until things started. Is there a better way?

 

[number two]

Charles-if you need to start the tractor and move it out of the mud to a better place to repair it,you could remove the wire from the shutoff solenoid at the fuel pump so the engine can't turn itself off.Then jump 12 volts to the small terminal at the starter solenoid to crank the engine to start.Use the key for a little glow plug time first.Drive tractor to the desired spot and reconnect the wire at the shutoff solenoid to stop the engine,using key switch if needed.Good Luck!

 

[DiezNutz]

Charles, a number of things you say don't make sense. I too have a replacement seat from Messick's, replacing it only involved the hinge at the front, didn't involve touching the switches or wiring. There are no connections "in" the seat itself. What "top panel under the seat", there isn't any. The switches and wiring are right there, when you lift the seat up.

The OPC isn't in pairs, its in separate inputs.

No, I meant the wires to each switch are in pairs, each pair is in its own plastic loom. If you tore all that apart, then I guess they wouldn't be anymore.

Yes the Red w/Black stripe wires are +12V from the 5A fuse which is on the switched power circuit, the other wires go back to the OPC like how I described the circuits in my first couple posts. If you haven't checked the 5A fuse to see if it's blown, that might be a really good idea now... Check all of them while you're at it.

My thought was to jump the various connections going in to the opc until things started. Is there a better way?

Please do not do this. Almost anything is a better way.

 

[Charlesaf3]

Charles-if you need to start the tractor and move it out of the mud to a better place to repair it,you could remove the wire from the shutoff solenoid at the fuel pump so the engine can't turn itself off.Then jump 12 volts to the small terminal at the starter solenoid to crank the engine to start.Use the key for a little glow plug time first.Drive tractor to the desired spot and reconnect the wire at the shutoff solenoid to stop the engine,using key switch if needed.Good Luck!

Thanks! That would be awesomely useful. Its not the shutoff solenoid that's currently the issue, though, the engine isn't getting starting current at all. Would jumping directly to the starter motor hurt anything? I was trying to figure out how the electricity would go once the starter motor kicked it on - I figured the OPC would shut it off, no? Hesitated to mess with it without knowing.

 

[Charlesaf3]

Charles, a number of things you say don't make sense. I too have a replacement seat from Messick's, replacing it only involved the hinge at the front, didn't involve touching the switches or wiring. There are no connections "in" the seat itself. What "top panel under the seat", there isn't any. The switches and wiring are right there, when you lift the seat up.


No, I meant the wires to each switch are in pairs, each pair is in its own plastic loom. If you tore all that apart, then I guess they wouldn't be anymore.

Yes the Red w/Black stripe wires are +12V from the 5A fuse which is on the switched power circuit, the other wires go back to the OPC like how I described the circuits in my first couple posts. If you haven't checked the 5A fuse to see if it's blown, that might be a really good idea now... Check all of them while you're at it.


Please do not do this. Almost anything is a better way.

Sorry, I wasn't being clear enough. Messick swapped in a seat from one of the pro lawn mowers. Its much more comfortable, but in the process they had to mess with the original seat wiring, since the new seat is suspension etc and wouldn't trigger the seat switch otherwise. Its the same in the looms, but different past the splices, which are pretty unique to my machine. So at first I thought i was a splice problem, and I took all the splices off (easy enough to rewire), but I neglected to label them and then the next morning did the usual forgetting which went where.

Panel wise - I'm referring to the sheet metal under the seat, which seems to be the only way to get access to the PTO lever switches. I REALLY don't want to go there, I've got too many parts, and too little tractor as it is.

Checking the 5A... no, I haven't. Probably a good idea. I assumed it would be fine since all other electrical on the tractor works fine, but if the 5a only feeds the OPC, that might be my problem. Boy, wouldn't that be nice. hmmm. I could have easily shorted that while messing wit the wires.

Why would jumping from the 5A to the OPC, connector by connector, to see which the bad circuit is, be bad? Worry about feeding too much juice into the OPC?

I've got a Fluke Multimeter, if there would be a better way to check with that. I'm about the opposite of expert with it, though, bought it because I figured I have to learn how to use one, not becase I already know...

Thanks again for all the help. I figure its not just useful for me, but for the next person who has issues with the OPC (a pretty common problem, per dealers).

 

[DiezNutz]

Sorry, I wasn't being clear enough. Messick swapped in a seat from one of the pro lawn mowers. Its much more comfortable, but in the process they had to mess with the original seat wiring, since the new seat is suspension etc and wouldn't trigger the seat switch otherwise. Its the same in the looms, but different past the splices, which are pretty unique to my machine. So at first I thought i was a splice problem, and I took all the splices off (easy enough to rewire), but I neglected to label them and then the next morning did the usual forgetting which went where.

Panel wise - I'm referring to the sheet metal under the seat, which seems to be the only way to get access to the PTO lever switches. I REALLY don't want to go there, I've got too many parts, and too little tractor as it is.

OK I'm with you now, thanks for clearing all of that up. Although I have no idea how Messick's modified your original wiring, hopefully not too much.
I thought you were saying you needed to remove some panel to get to the wiring for the seat switches.
No, let's not worry about the PTO lever or HST pedal until you've fixed the seat switches.

Checking the 5A... no, I haven't. Probably a good idea. I assumed it would be fine since all other electrical on the tractor works fine, but if the 5a only feeds the OPC, that might be my problem. Boy, wouldn't that be nice. hmmm. I could have easily shorted that while messing wit the wires.

Those were my thoughts exactly. Yes from what I can tell the purpose of the 5A fuse is for the OPC, so it's definitely worth a look.

Why would jumping from the 5A to the OPC, connector by connector, to see which the bad circuit is, be bad? Worry about feeding too much juice into the OPC?

Aside from the fact that you might jumper 12V into a connection that isn't supposed to see 12V and short out your OPC, it's just a waste of time. The OPC looks at a certain combination of inputs to decide what to do in a given situation; there's a logic truth table about a page & a half long in the WSM. The chances that you'll randomly come up with the right answer and not damage something are nil.

I've got a Fluke Multimeter, if there would be a better way to check with that. I'm about the opposite of expert with it, though, bought it because I figured I have to learn how to use one, not becase I already know...

Need to rule out the simplest things first. Like I said before, jumper the seat bottom switch ONLY. Use your Fluke to make sure that the tilt switch at the front of the seat only has continuity across the terminals when the seat it up, and is open (infinity) when the seat is down.
Check the 5A fuse.
Put the seat down.
Tractor should start.

If it doesn't, then you can start checking other things.

Keep in mind, before you started troubleshooting you only had one simple problem. Need to try to wipe the slate clean and get back to where you started. If you can get the tractor to start, you're halfway home.

 

[Charlesaf3]

Yeah, I totally agree with all of the above.

I have the logic chart in the OPC chapter, so I was going to jump following that. I have the same nervousness about sending 12v where it doesn't belong though, even following the flowchart.

I really want to figure out which circuits are bad without hunting each down. The way things were acting I figured I had a bad HST pedal, but your theory about the fuse makes a lot of sense too - I'm going to go buy one and sub it to see. Is it obvious where in the fuse box the OPC fuse is?

Thanks again for your advice, its been very helpful

 

[DiezNutz]

I have the logic chart in the OPC chapter, so I was going to jump following that. I have the same nervousness about sending 12v where it doesn't belong though, even following the flowchart.

I really want to figure out which circuits are bad without hunting each down. The way things were acting I figured I had a bad HST pedal

I guess if you're really really careful...
... just doesn't seem like the simplest way to go about this.
The HST pedal seems unlikely. From the way you described the original problem, it sounded like the seat bottom switch. The HST pedal was already engaged, so that wouldn't have made the tractor quit on you. The seat switch would have though.

but your theory about the fuse makes a lot of sense too - I'm going to go buy one and sub it to see. Is it obvious where in the fuse box the OPC fuse is?

There is only one 5A fuse and it should be the one on top.