Electrical Issue

[woodlandfarms]

So, things are suddenly going south on the PT. And in an area that I think PT has failed miserably in, which is electrical.

My system is protected by one circuit breaker, making identification of a failing system impossible in my opinion to track down.

I just cleaned my ground terminals, and found a short in a seat wiring, but what is happening is randomly the engine is shutting down, and in doing so it is blowing the breaker. What is weird is that the engine starts to conk out, then comes back, conks again then dies with the breaker popping at that moment. I don't know if there is a thermal disconnect on the breaker (meaning it momentarily opens thus starting to stall the engine, cools and reconnects then the engine winds back up then dies again, popping the breaker).

Any thoughts on how to trouble shoot an intermittent electric with only one breaker?

 

[MossRoad]

Unfortunately, you would have to disconnect all electrical systems and then hook them back up one-by-one until you find the one that is causing the problem. Bummer.

 

[BobRip]

You could disconnect one half the loads and see if you still have a problem. It the problem persist at that point then it is in the loads you left connected. Then disconnect one half the remaining loads and see what happens. This enables you to resolve the problem much quicker than one item at a time. This is called the split half technique. If this is not clear I can elaborate a little more, but you probably get the idea.

 

[ponytug]

If the engine is conking out, then the fuel solenoid is cycling. That could be happening because you are drawing all the power down before tripping the breaker, or because something is worn in the cable to the solenoid. Have you tried cleaning the contacts on the engine interconnect? The one that must be disconnected when bleeding the air out of the main hydraulic filter?

If I were you, I would give the cables a once over, especially the ones behind the dash and at the main electrical box. I would also consider that grounding might be an issue (battery, engine, front to rear). I put in extra grounds from the dash and the engine/battery to a single point on the rear tub, just to keep from having to run down weird grounding issues later.

My PT has a 14(?) wire custom cable running the dash to the main electrical box. If you are getting too much grief, I'd replace the whole thing and be done with it. My memory is that I found a second source besides PT, by getting to the right wire number and guessing on the the wire gauges. It sounds like you have a lot of wear in the tunnel.

Good luck! I hate running down intermittent issues.

All the best,

Peter

So, things are suddenly going south on the PT. And in an area that I think PT has failed miserably in, which is electrical.

My system is protected by one circuit breaker, making identification of a failing system impossible in my opinion to track down.

I just cleaned my ground terminals, and found a short in a seat wiring, but what is happening is randomly the engine is shutting down, and in doing so it is blowing the breaker. What is weird is that the engine starts to conk out, then comes back, conks again then dies with the breaker popping at that moment. I don't know if there is a thermal disconnect on the breaker (meaning it momentarily opens thus starting to stall the engine, cools and reconnects then the engine winds back up then dies again, popping the breaker).

Any thoughts on how to trouble shoot an intermittent electric with only one breaker?

 

[woodlandfarms]

Well, thought i had it all handled. First I cleaned all wires up, looked at all the connections. I pulled the ground on the battery side and cleaned it. Just then My wifes uncle stopped by, nice guy, ran a pulpmill since he was a kid and knows mechanics inside and out. Anyway, he quickly isolated the PTO wire saying it looked like it had rubbed down and was making contact. He threw some tape around it and all was good with the world.

I have been mowing since 2PM and it just conked out again (4 hours of hard mowing). Of course it left me in a bad way and I had to walk out. Conked out the same way again.

Oh so darn frustrated.

Never have had electrical issues with the PT. I now the electrical system is basically a very bad design but did not see this as happening.

 

[CobyRupert]

So, things are suddenly going south on the PT. And in an area that I think PT has failed miserably in, which is electrical.

My system is protected by one circuit breaker, making identification of a failing system impossible in my opinion to track down.

I just cleaned my ground terminals, and found a short in a seat wiring, but what is happening is randomly the engine is shutting down, and in doing so it is blowing the breaker. What is weird is that the engine starts to conk out, then comes back, conks again then dies with the breaker popping at that moment. I don't know if there is a thermal disconnect on the breaker (meaning it momentarily opens thus starting to stall the engine, cools and reconnects then the engine winds back up then dies again, popping the breaker).

Any thoughts on how to trouble shoot an intermittent electric with only one breaker?

Sounds like it's shorting to ground (frame), drawing off current (and voltage) to the fuel solenoid. Maybe it cuts in and out when the wires are vibrating (shorting, not shorting), but if it shorts for too long ( basically in a short there's no resistance between the +12V terminal and the -neg terminal/frame), thus a large short current, so the fuse blows.
Check that there's enough tape (more than 1 layer) where wires were "fixed" on switch. Looking for sparks is easier in the dark.

 

[MossRoad]

You could disconnect one half the loads and see if you still have a problem. It the problem persist at that point then it is in the loads you left connected. Then disconnect one half the remaining loads and see what happens. This enables you to resolve the problem much quicker than one item at a time. This is called the split half technique. If this is not clear I can elaborate a little more, but you probably get the idea.

That's a very good suggestion. Just keep dividing the potential problem points in half.

 

[Coyote machine]

The other possibility is the breaker itself is faulty. Is it anything special, or just a standard automotive type that could be easily replaced? Another thing to do while working on the wires that come close to frame members is to put them into loom so there is less/no chance of shorting to the frame.
Can you get us some pics of the general mess of wires so those not familiar with the machine can think on it some?
What age /condition is the battery in? The age of the machine/# of hours on same. Condition of ignition switch, starter, alternator, etc. Any gauges like volt/amps/ etc.?

 

[ponytug]

Carl- Sorry to hear about the walk out. That's got to be frustrating. If the battery is old, it is not out of the question for the post or one of the cell connectors internally to have fractured, especially given the sort of use that I suspect you have put it through. If you have already cleaned, and check the main + & - leads off the battery, and the battery is old, I would consider it. It is easier and cheaper than replacing the main wire bundle.

I agree with Coyote Machine that it isn't out of the question for the breaker to die, but I don't know how to prioritize it against everything else going on.

All the best,

Peter

 

[Coyote machine]

Carl- Sorry to hear about the walk out. That's got to be frustrating. If the battery is old, it is not out of the question for the post or one of the cell connectors internally to have fractured, especially given the sort of use that I suspect you have put it through. If you have already cleaned, and check the main + & - leads off the battery, and the battery is old, I would consider it. It is easier and cheaper than replacing the main wire bundle.

I agree with Coyote Machine that it isn't out of the question for the breaker to die, but I don't know how to prioritize it against everything else going on.

All the best,

Peter

I'm throwing the breaker into the equation so it doesn't become overlooked when it's right in front of one's face, so to speak. And because it is the only breaker keeping the entire harness from frying extra crispy it is more prone to failure than if there were multiple breakers protecting various circuits; wow, what a concept- multiple breakers! Gotta throw some levity into frustrating situations to lighten things up and put them into perspective. Look at it this way, OP, when you're done, you'll have a better, more reliable machine going forward.
In addition to the battery being a possible piece of toast, you should try moving the ground cable with rubber glove on, to see if anything happens while the machine is running with lights on, etc. Sometimes corrosion is hidden inside the actual cable and it can no longer handle the current passing through. Make the battery post and their respective connectors shiny metal clean and tight. Check each cell with a specific gravity syringe tool, and if questionable remove it and get it load tested at your local Autozone or equivalent store. Failure of load test is time for a new Interstate battery sized to your machine. Always a good idea to start at the battery and work out to wherever the problem leads. Take a close look at the ignition switch, connections to starter, etc. to be sure there is no evidence of corrosion at the cable ends or especially inside the sheathing of the bigger wires to the starter, etc. Is there any type of fuse box in addition to the single breaker or is that the last and only line of defense?

 

[woodlandfarms]

Thank you to everyone so far. I see the writing on the wall very clearly. This is not going to be an instant fix. As the machine is so intermittent, not sure who either the spark idea or puling half the system will work, not impossible but could be months before the short is tracked down.

The temptation is very high to re-wire the entire tractor, I have plans someone made here on the net and it is a much, much better diagram. And it is something I am capable of.

The half and half is a good start, and the breaker is a pop out type breaker. It gets hot, pops out, wait for it to cool an push the breaker back in. And yes, only one breaker for the entire electrical system. PT keeps things simple, except for Wiring. Wiring on the PT is a mess. We have screw mount panels. 2. One next to the engine (nearly inaccessible) and the other under the dash.

I am savvy to electronics and automotive electrical for the most part so don't be afraid to push me.

As for the battery. It is the one my PT came with in 2007 (Ken, was it 07?). It could be a bad cell for sure. I just have been focused on wiring as I am finding so much abraded.

So yes, it could be a bad breaker. Could be a bad battery. it could be i just do a re-wire I have always wanted to do.

 

[BobRip]

Thank you to everyone so far. I see the writing on the wall very clearly. This is not going to be an instant fix. As the machine is so intermittent, not sure who either the spark idea or puling half the system will work, not impossible but could be months before the short is tracked down.

The temptation is very high to re-wire the entire tractor, I have plans someone made here on the net and it is a much, much better diagram. And it is something I am capable of.

The half and half is a good start, and the breaker is a pop out type breaker. It gets hot, pops out, wait for it to cool an push the breaker back in. And yes, only one breaker for the entire electrical system. PT keeps things simple, except for Wiring. Wiring on the PT is a mess. We have screw mount panels. 2. One next to the engine (nearly inaccessible) and the other under the dash.

I am savvy to electronics and automotive electrical for the most part so don't be afraid to push me.

As for the battery. It is the one my PT came with in 2007 (Ken, was it 07?). It could be a bad cell for sure. I just have been focused on wiring as I am finding so much abraded.

So yes, it could be a bad breaker. Could be a bad battery. it could be i just do a re-wire I have always wanted to do.

If you have a clamp on DC ampmeter it would be a big help. Your intermittent short could be happening a lot, but for very short time intervals, which the meter could see. Only if the short last longer, say a few seconds, would the breaker trip. You could then wiggle wires, move the meter around, etc. You could also add a mutlfuse holder and break out your loads. This would be a good thing for future problems as well as helping with your immediate problem. I have done a lot of trouble shooting in my life and the worst ones are the intermittent problems.
Oh, just thought of another idea. Put a large 12 volt bulb across the breaker and open the breaker. A head lamp or two in parallel might do it. Have somebody watch the bulbs as you wiggle components. Of course if it is a thermal problem with the component failing only when it gets hot this might not work. You can simulate thermal conditions with a hair dryer. This enables you to heat one component at a time. Keep at this and keep posting and you will find it.

 

[MossRoad]

A 7 year old battery will bite you in the butt. They lasted 6 on my PT425. But batteries are not cheap any more, as in a hundred bucks easy. Have it tested for free at Autozone, as suggested just to eliminate that possibility.

 

[woodlandfarms]

i have to go into town today so I will take the battery with me.

 

[ponytug]

If you are having tested, I would do more than just a load test (fitness), but also have them check the internal resistance (which should show up a fractured post or interconnect).

All the best,

Peter

 

[woodlandfarms]

They did both, its a negative on the battery. tired but in good shape.

but my Tractor has Hungry Butt. OK, it means when your shorts suck up the crack. The wire I repaired for the seat yesterday was very very tight, It seems turning back and forth for 4 hours cause the wire to suck back into the tub. OK. I know, it seems weird.

I am going to go a step further with the volt meter, good idea...

Here is a question for the group, where do I buy wire for my PT that has the bonus covering as these wires are subjected to lots of abuse traveling through the center of the tractor.

 

[ponytug]

You can get wire loom or spiral wrap from Amazon, or any auto parts store. If you are doing a new install, I would go with woven wire loom (not split) to get through the tunnel; it won't hang up on things as much. The spiral is better protection, but it will be a piece of work to fully cover the cables and then fish them through. I have spiral wrap of varying sizes on all my hydraulic lines, and all but the smallest of the wires on my PT. The wrap is either nylon or HMWPE, which can take a lot of abrasion.
Good luck!
Peter

 

[washita]

If you can source it use mil-spec wire when building a new wiring harness, tough to work with but worth the effort has been my experience.

 

[BobRip]

I don't see how a battery can blow a fuse. But a battery that old should be tested.

 

[CobyRupert]

I don't see how a battery can blow a fuse. But a battery that old should be tested.

Exactly! It wouldn't. Neither would a bad neutral, no need to move the neutral around. Yes it could of been a bad breaker, but very likely a hot wire is shorting to neutral/ground (frame) somewhere before the load, this causes a lot of current to flow into the short, the breaker then pops if the short continues for longer than the breaker can handle it.

Breakers don't trip at a magic number of amps, it's always a combination of amps for a duration of time. Example (making up numbers, but close) a 30 amp breaker can pull 35 amps for many minutes. 40 amps for a few seconds. 60 amps for a second, and will trip very quickly when a short faults at 100+ amps.