B2710 Completely dead/ no power ... HELP!

[ETXKubota]

I have a B2710 that ran great all summer, but as the temps got a little cooler this fall it began having issues with slow starts. Every once in a while I could turn the key on but nothing, no power to crack, no power to the dash lights, nothing. Now that's all I got. EVERY ONCE IN A WHILE I'll get the dash lights to light up, but as soon as I turn the key to preheat, they all go out. I've pretty much taken all the panels and moldings off and have full access to the wiring harness and all the parts. Here's what I've addressed thus far...

- The battery is brand new. This is the first thing I replaced.
- All fuses are good. I've checked and tripled checked.
- Pulled the bolt out for the main ground on the frame, cleaned it, and reinstalled. Checked for good grounds all over the frame, chassis, and engine block. I'm good there.
- Checked all the safety switches and have good continuity all all of them. PTO/ Trans/ and clutch.
- I've pulled the starter relay and checked it per the WSM. It's got good continuity.
- Replaced the ignition switch this morning. I thought this was it even though the old switch had good continuity as well.

I know I've checked other things as well, but it's getting late and I'm tired ... I've been crawling all over this thing for two days with a test light and voltmeter. I'm so frustrated and stumped as to what could be causing the total power loss. Everything I think about checking or rechecking doesn't explain the total loss. I keep going back to a short or blown fuse someplace. Are there fusible links somewhere in the harness that I'm not tracking?? Another fuse box besides the one on the "firewall" I'm missing??

I've just joined this forum, but have read plenty here already. Really appreciate the help I've gotten thus far. Hoping someone can help me with this specific issues .... I've got tons of work to catch up on!

 

[Roadworthy]

You may have already, but remove both battery terminals from the battery. Clean the inside of the cable terminal as well as the battery terminals themselves. Check the integrity of the cable where it enters the fitting at both ends. You have a significant voltage drop somewhere. After going through this routine if it still doesn't work put a voltmeter on the battery. See how badly the voltage drops when you turn on the key and again when you energize the glow plugs. It may go below twelve but should not go below ten.

 

[ETXKubota]

You may have already, but remove both battery terminals from the battery. Clean the inside of the cable terminal as well as the battery terminals themselves. Check the integrity of the cable where it enters the fitting at both ends. You have a significant voltage drop somewhere. After going through this routine if it still doesn't work put a voltmeter on the battery. See how badly the voltage drops when you turn on the key and again when you energize the glow plugs. It may go below twelve but should not go below ten.

I've taken all the ring terminal connections off and cleaned everything to both ends. Checking at the starter, I'm getting 12.5V there so that should be good, BUT ... that's just with the key "on". Not starting. I'd agree with the idea that there may be a significant voltage drop someplace, but I'm at a total loss as to where/ what to check. I've been all over this thing, but I agree ... I need to get more thorough with my voltmeter.

 

[200mph]

Do a voltage drop test on the major circuits in question.

 

[ETXKubota]

Do a voltage drop test on the major circuits in question.

Thanks for the input guys ... While I'm not new to mechanics ( I work on old Jeeps), I'm still pretty new to this tractor. 200, would you mind giving me a short list of the "major circuits" I'm wanting to look at??

 

[BigG]

I do not know if this applies or not but try replacing the ground wire itself. I just went through this on one of my trucks. A new alternator, new battery, cleaned connections and the damn thing would not start at times for months. Replaced the negative cable and poof no more problems. The old one showed no signs or wear.

 

[ETXKubota]

I do not know if this applies or not but try replacing the ground wire itself. I just went through this on one of my trucks. A new alternator, new battery, cleaned connections and the damn thing would not start. Replaced the negative cable and poof no more problems. The old one showed no signs or wear.

Worth a shot ... and why not, cables are cheap enough. Thanks BigG.

 

[SidecarFlip]

12.5 volts static won't cut the mustard, Static charge on a flooded cell should be close to 13 volts at rest.

You need to fully charge the battery and then do a load test with a carbon pile to determine the viability of the battery first. Just because it's 'new' don't mean it's good or charged.

 

[ETXKubota]

12.5 volts static won't cut the mustard, Static charge on a flooded cell should be close to 13 volts at rest.

You need to fully charge the battery and then do a load test with a carbon pile to determine the viability of the battery first. Just because it's 'new' don't mean it's good or charged.

I don't have access to a carbon pile tester. With the battery just sitting there, what should I be seeing? With the engine running, sure I'd expect to see a higher reading, but just sitting there I didn't see anything wrong with 12.5. I'll put a charger on it in the morning.

 

[GreensvilleJay]

OK, I don't have that tractor but 'usual stuff to try'...
Disconnect the alternator to battery connection.
Try bypassing the starter solenoid and connect battery to starter with jumper cable. It should spin. if not battery is not charged or bad cable(s). It shouldn't start as key is off,so fuel solenoid is off.
From the 'story' , it sounds like the alterntor is pooched and original battery died from not being charged. An internal problem in the alternator can slowly drain a battery.
Hopefully the WSM has a good wiring diagram, that you NEED !

 

[BAP]

You may have a safety switch that isn’t closing properly. Even though they test ok, as it gets cold and everything shrinks a little, the contact tabs that push the switch in may not be activating enough. Try bypassing them to see if it starts. If so, you may need to adjust them so they work properly.

 

[Henro]

Just to eliminate the possibility of a bad, but new, battery, hold the volt meter probes on the battery terminals and watch the battery voltage as someone tries to start the tractor. Do not touch the cable clamps.

If voltage drops significantly when trying to start, the battery is the issue. If voltage stays up, problem is external to the battery.

Hold the leads on the cable clamps. Or even better, stick them through the insulation beyond the clamps. You should read full voltage. If Voltage drops when you try to start, you have a bad connection at one of the clamps.

One at a time, hold your probes between each battery terminal and the wire connected to its clamp. You should read zero volts. If voltage appears when you try to start you have a bad clamp connect at that terminal or cable/clamp connection.

These tests will pretty much eliminate the possibility of a bad battery or connections to it.

Proceed down the line in a similar fashion and you WILL find your problem.

Edit: I believe you said the lights go out when you try to start. If so the root issue is unlikely a safety interlock problem.

 

[ETXKubota]

Thanks for all the replies guys. I'm finding this site to be very friendly and very helpful. I appreciate that.

Here's where I'm at this morning... May be dead in the water until parts can get here after Christmas.

I hooked up a battery charger this morning and rechecked voltage at the starter. I'm now getting 14.3v which is an improvement, so I'll leave the charger on for a minute. I'm also getting dash lights now when I key the ignition to "on". Not sure what changed other than maybe my new battery was just that low. I'm also getting the glow-plug light when I turn the key to "preheat". Getting my test light back out, I turn back to the ignition switch. I'm getting power into the switch and when keyed "on", I'm getting power out. Back to the starter, I put my test light on the power tab that triggers the solenoid. When I keyed the ignition to "start", I get nothing. So, I backtracked to the starter relay (hidden up behind the dash up by the fuel sending unit). When keying the ignition to "start" I'm getting signal to the relay, but not through it. I tested this relay per the WSM for continuity yesterday and it said it was good, however, if power isn't getting through to signal the starter solenoid, that's a problem. May see if I can get a replacement here locally today, but being a Sunday, that's a stretch. I may just have to order a replacement and see where that gets me when it comes in. ... Would making a jumper wire and bypassing the relay be a bad idea just to see if the solenoid triggers? Not as a solution, but a test??

I don't see anything getting fixed today, but I feel like I've made some progress this morning. Better than the last two days I guess!

 

[GreensvilleJay]

well it does sound like a bad relay..
I would bypass it and see if the starter spins.

I assume you have a GOOD wiring diagram /schematic of the tractor ?

Some 'starter relays' need both a +12 signal AND ground signal to operate.....hence the need for a true schematic !

 

[ETXKubota]

well it does sound like a bad relay..
I would bypass it and see if the starter spins.

I assume you have a GOOD wiring diagram /schematic of the tractor ?

Some 'starter relays' need both a +12 signal AND ground signal to operate.....hence the need for a true schematic !

That's a good point. I'm looking at diagrams found in an online WSM, so that 's what I've got to work with. The relay does attach to a metal bracket, but the relay's housing is plastic, so it doesn't get it's ground from there. I'll go back out and double check that its getting a good ground though. I've also been reading some that people have just used a jumper from the + on the battery to the trigger tab on the solenoid to get the tractor to start. I may try this as well.

Having the WSM on line is nice, but I'm a hard-copy kind of guy... I may end up ordering on off ebay or something. I picked up something similar for my '81 Jeep CJ7 and it has been priceless!

 

[ETXKubota]

Well F ...

So, I went out and tried to use a jumper from the + battery terminal to the trigger on the starter solenoid. All I got was the starter pops out but doesn't spin. So, I'm guessing my starter is bad as well .... BUUUUUUUUT .... now I'm back to square one. NOTHING works again. No dash lights, power to the ignition switch but none through the switch when I rotate the key to "preheat" or "start".

I'm so frustrated/ lost on this thing ... Anyone need a free tractor???

 

[GreensvilleJay]

sure, delivery included ??

Heck I feel your pain... I don't have a good, clear schematic for my BX23S, even after downloading 3 'versions' of the WSM.
Hmm... 'nuthin again'..
Check the battery voltage, it should be at least 13.2. If not put a good charger on it ,depending on charger it could take overnight.

You could wire up a 2nd battery with jumpers and try again....
Sorry, no passport, so I can only offer help this way.



OK, I downloaded a WSM for your machine, at least it's got a GOOD, READABLE wiring diagram. The starter relay gets its power from a 5 amp fuse. However in order for it to energize you need clutch pedal, PTO and HST safety switches to ALL be in the correct positions.....ANY of them 'open' and no start !
Jay

 

[ETXKubota]

sure, delivery included ??

Heck I feel your pain... I don't have a good, clear schematic for my BX23S, even after downloading 3 'versions' of the WSM.
Hmm... 'nuthin again'..
Check the battery voltage, it should be at least 13.2. If not put a good charger on it ,depending on charger it could take overnight.

You could wire up a 2nd battery with jumpers and try again....
Sorry, no passport, so I can only offer help this way.



OK, I downloaded a WSM for your machine, at least it's got a GOOD, READABLE wiring diagram. The starter relay gets its power from a 5 amp fuse. However in order for it to energize you need clutch pedal, PTO and HST safety switches to ALL be in the correct positions.....ANY of them 'open' and no start !
Jay

Thanks for your input, Jay ... I know it's got to be something simple. These things aren't computer driven, so it can't be that complicated ... that's what's driving me nuts. And sorry, brother, but you're going to have to passport up and come get this thing. HAHAHA! All my fuses and safety switches continue to check out ok. I'm checking the safety switches unplugged, in place, with the levers/ pedals triggering the switches.

I've also gone ahead and purchased a new starter and starter (Comp Relay #68881-53540). They will probably be here after the first of the year. Guess, I'm not getting any work done until at least 2020.

 

[whitetiger]

Well F ...

So, I went out and tried to use a jumper from the + battery terminal to the trigger on the starter solenoid. All I got was the starter pops out but doesn't spin. So, I'm guessing my starter is bad as well .... BUUUUUUUUT .... now I'm back to square one. NOTHING works again. No dash lights, power to the ignition switch but none through the switch when I rotate the key to "preheat" or "start".

I'm so frustrated/ lost on this thing ... Anyone need a free tractor???

Put your voltmeter positive on the battery stud of your starter and the ground Negative to a good ground away from the battery. Watch the voltage and try to jump between the battery post to the solenoid engage post on your starter. I suspect your voltage will drop to near zero.
I am leaning toward a bad battery cable or connection as you have intermittent current until a load is applied, then none.

 

[KennysNewFarm]

https://www.coppard.co.uk/pdf_admin/Kubota B2410 service manual.pdf

WSM Manual for your tractor.