What damage can repeated Jump Starting cause?

[lugbolt]

Since this is an HST, I may consider a bypass of the seat switch, so I can leave the tractor idling and climb down. Right now when I stand the engine stops.

Thanks again.

if this is on the tractor in the signature (L2501), then your HST switch or PTO switch or their circuit is telling the tractor that one of those two is "in gear". Should be able to step off of tractor with the engine still running assuming the switches are working properly.

 

[Sparty047]

BTW.....since this is a hydrostatic drive I do not fear being run over when starting it up. I do as a habit climb up into the seat to start it. As for the PTO..... I only engage it from the seat, and lways turn it off well before stopping the engine.

When I get an engine start button wired in I will of course check to see if safety relays remain in play. I do know already that the seat occupancy switch must be engaged for the main switch to send current to the starter relay harness....so may find the PTO alo must be off and the HST pedal must be in center position. Will post results.

Just EXACTLY what are you trying to do?

Just EXACTLY what are you trying to do?

Now I am confused.... your tractor has a "starter relay" ????

Most engines which use a bendix type of starter has a relay built into the starter.
Does your starter have ONE BIG WIRE... or also have a small 'signal' wire to initiate starting?

Explain again why you do not simply FIX the problem instead of rewiring the starting system?

Using VOLTAGE DROP TESTING should take no more than 10 minutes to isolate the problem. At that point, your only issue would be to decide HOW to fix it.

Most engines which use a bendix type of starter has a relay built into the starter.
Does your starter have ONE BIG WIRE... or also have a small 'signal' wire to initiate starting?

Explain again why you do not simply FIX the problem instead of rewiring the starting system?

Using VOLTAGE DROP TESTING should take no more than 10 minutes to isolate the problem. At that point, your only issue would be to decide HOW to fix it.

Early on I did a voltage drop test between the battery and starter motor which was A-OKAY. Is everyone referring to only this test when they say Voltage Drop Test?

The starter circuit has a starter relay switch (Kubota term in their shop manual) that is activated when the key is turned.... this is NOt to be confused with the relay incorporated into the starter motor itself. For added detail please refer to my earlier thread on the "electrical issue with my starter system".

I am NOT bridging at the starter motor itself.....I am "bridging" the red and black leads coming into the starter rely harness which holds the starter relay switch....(the one located behind the cowling above the instrument cluster) because the Problem I Must FIX has zero to do with the starter motor. IT is that the black lead is NOT delivering battery voltage (due to some very high impedence within the circuit leading to it). Because the Red lead carries 12.7V and the Black only 10.7 (not 12.7) this "starter relay" is NOT activated and does not send on a current to the smaller terminal at the starter motor.



I am faced with a voltage drop in the circuit that is activated when the main switch is turned to "on." If you review my earlier thread I pasted the entire "starter system check section." I am not going to do it here!.. If a version of the voltage drop test exists that can be used within the starter circuit I have yet to find it. If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

Hope this clears things up!
Thanks.

 

[Sparty047]

There seems to be some confusion about my use of the term starter relay:

I have attached page 422 of the Kubota shop manual for the L2501HST. You will see that they use the term "Starter Relay" to ID the relay in the engine start system. When I perform the harness testing with the main switch "on" terminal A reads 1.5V lower than the battery!!!



Some are confusing my use of this term with the relay on the starter motor itself and then proceed to debate whether I mean "solenoid" or "starter relay" on that motor. The answer is: NEITHER - there's nothing wrong with my starter motor!



BTW- - very early on I did a voltage drop test between the battery and starter motor which was just fine/ A-OKAY. Is everyone referring to only this test when they say Voltage Drop Test?



AGAIN - The starter circuit has a starter relay switch (Kubota term in their shop manual) that is to be activated when the key is turned.... this is NOT to be confused with the relay that is incorporated into the starter motor itself.


SO WHEN I SAY HOT WIRE START:
I am NOT bridging at the starter motor itself.....I am "bridging" the red (C) and black (A) leads within the starter relay harness ( which holds the starter relay switch and is located behind the cowling above the instrument cluster).

The Problem I Must FIX has zero to do with the starter motor. It is that the black lead is NOT delivering battery voltage (due to some very high impedance within the circuit leading to it when the key is turned). Because the Red lead carries 12.7V and the Black only 10.7 (not 12.7) this "starter relay" is NOT activated and does not send on a current to the smaller terminal at the starter motor. I found I can simply bridge A to C and send a signal to the starter motor (It obviously doesn't matter that there's a voltage gap.



So the crux of my problem is that I cannot isolate and fix the source of high impedance to the A lead that prevents the starter relay from switching on.

SO -If there a version of a voltage drop test exist that can be used to isolate my problem within the sta ter circuit, I have yet to find it. If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

Hope this clears things up!
Thanks again.
Dennis

 

[BruceP]

If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

You need to UNDERSTAND "Voltage drop testing" to use it. OHMS LAW is your guide. (A straight wire should have 0.00V across its length)

Clip meter-negative lead on battery plus and LEAVE IT THERE.
Then begin tracing the circuit in question (starter signal) until you locate where the voltage is more than 50mV when cranking engine.
It is that simple.

• Some folks like to begin probing at the starter and work back until they see 0.00v
• Other folks prefer to begin probing at the keyswitch and work towards the starter until they find the voltage-drop.

Your choice...

Either way - you end up finding the problem within 5 minutes.
Since you HAVE the schematic it is truly trivial.

If it makes it easier for you... PRINT OUT the schematic and hilight the starter-signal circuit from battery-plus to the starter. Then, WRITE DOWN each voltage (while cranking) at the location you are probing on the printout.

 

[Pau7220]

SO -If there a version of a voltage drop test exist that can be used to isolate my problem within the sta ter circuit, I have yet to find it. If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

Plenty of YouTube videos on this…
The test is always the same … just a matter of where you test the circuit.
Test must be done under a load.
If your problem is from the the ignition switch to the starter, that’s where you test.
You also need to test for voltage drop from battery to the ignition switch.

 

[Flintknapper]

Either way - you end up finding the problem within 5 minutes.

^^^^^^

I would argue this.

Yes, IF the circuit is a simple one AND all the wiring, connections and components are easily reached. NO, IF the voltage drop is the result of resistance/damage in an area of the wiring harness that is bundled and not easily reached, probed or repaired.


Also, it needs to be known which components or wiring are to receive what amount of voltage. Not all components are necessarily supposed to receive 12vdc and certain others will operate fine within a 'window' of voltages.

So Voltage drop....while a useful diagnostic tool may or may not help a person if not benefited by knowing how much voltage is supposed to be supplied where (FSM is useful there).

In the OP's case....I would begin by bench testing the relay itself....just to prove it out. Apply 12vdc and inspect for physical function AND measure its resistance. After that... work the circuit back (from relay through the starting circuit) until you find your voltage drop or discover a bad connection or wire damage. Damage from rodents chewing on wiring can be well hidden.

OP can certainly add a momentary starting switch to bypass the relay and operate the solenoid on the starter.....BUT it will almost certainly bypass all or most of the safety switches incorporated in that circuit.

I would rather spend the time finding and repairing the actual problem than circumventing it with a bypass. But if an emergency situation exists.....a temporary bypass would get him going.

 

[TheOldHokie]

BTW.....since this is a hydrostatic drive I do not fear being run over when starting it up. I do as a habit climb up into the seat to start it. As for the PTO..... I only engage it from the seat, and lways turn it off well before stopping the engine.

When I get an engine start button wired in I will of course check to see if safety relays remain in play. I do know already that the seat occupancy switch must be engaged for the main switch to send current to the starter relay harness....so may find the PTO alo must be off and the HST pedal must be in center position. Will post results.


Early on I did a voltage drop test between the battery and starter motor which was A-OKAY. Is everyone referring to only this test when they say Voltage Drop Test?

The starter circuit has a starter relay switch (Kubota term in their shop manual) that is activated when the key is turned.... this is NOt to be confused with the relay incorporated into the starter motor itself. For added detail please refer to my earlier thread on the "electrical issue with my starter system".

I am NOT bridging at the starter motor itself.....I am "bridging" the red and black leads coming into the starter rely harness which holds the starter relay switch....(the one located behind the cowling above the instrument cluster) because the Problem I Must FIX has zero to do with the starter motor. IT is that the black lead is NOT delivering battery voltage (due to some very high impedence within the circuit leading to it). Because the Red lead carries 12.7V and the Black only 10.7 (not 12.7) this "starter relay" is NOT activated and does not send on a current to the smaller terminal at the starter motor.



I am faced with a voltage drop in the circuit that is activated when the main switch is turned to "on." If you review my earlier thread I pasted the entire "starter system check section." I am not going to do it here!.. If a version of the voltage drop test exists that can be used within the starter circuit I have yet to find it. If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

Hope this clears things up!
Thanks.

You are dealing with defeating/altering the interlock logic at that point. Your issue may be more than just a voltage loss due to a bad connection.

Dan

 

[BAP]

Many are so busy arguing about starter type that most all except Lugbolt have overlooked the fact that OP says he can’t get off tractor without it stalling. That means that he has a safety switch problem. Most likely for the PTO which, if so is why his tractor won’t start properly in the first place.

 

[Sparty047]

There seems to be some confusion:



Early on I did a voltage drop test between the battery and starter motor which was A-OKAY. Is everyone referring to only this test when they say Voltage Drop Test?

The starter circuit has a starter relay switch (Kubota term in their shop manual) that is activated when the key is turned.... this is NOt to be confused with the relay incorporated into the starter motor itself. For added detail please refer to my earlier thread on the "electrical issue with my starter system".

I am NOT bridging at the starter motor itself.....I am "bridging" the red and black leads coming into the starter rely harness which holds the starter relay switch....(the one located behind the cowling above the instrument cluster) because the Problem I Must FIX has zero to do with the starter motor. IT is that the black lead is NOT delivering battery voltage (due to some very high impedence within the circuit leading to it). Because the Red lead carries 12.7V and the Black only 10.7 (not 12.7) this "starter relay" is NOT activated and does not send on a current to the smaller terminal at the starter motor.



I am faced with a voltage drop in the circuit that is activated when the main switch is turned to "on." If you review my earlier thread I pasted the entire "starter system check section." I am not going to do it here!.. If a version of the voltage drop test exists that can be used within the starter circuit I have yet to find it. If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

Hope this clears things up!
Thanks.

 

[GreensvilleJay]

here's one way to test 'what's busted....'

referring to the diagram I put into post #35...

!!!!! be sure tractor's in neutral as you're bypassing the safety stuff...
turn ign key to ON position

1) locate the starter relay (4) and insert one end of a jumper wire into where the B/W wire is.
2) 'ground' the other end of the jumper.
starter relay should close, starter spin, engine may start.
if YES, then relay is GOOD.

3) move jumper to the B/Y ( Black/Yellow) connection of the PTO switch(8)
4) 'ground' the jumper.
starter relay should close, starter spin, engine may start.
if YES, PTO switch is good

5) move jumper wire to the opposite side of the HST switch(10) where the B/Y wire is. diagram doesn't show that color...
6) 'ground' the jumper
starter relay should close, starter spin, engine may start.
if YES, HST switch is good

7) if no, then CLUTCH switch(13) is bad

This test presumes that ONLY one switch is 'bad' ( high resistance) and the cause of the problem. As this is a series circuit, ALL 3 of them could be partially 'bad'. Say they each drop 0.5 volts. NOT a problem for ONE switch BUT in the 'string'.... 0.5+0.5+0.5=1.5 volts ,so relay will not energize.

The other place a voltage drop can occour is at the 5 amp fuse. Any corrosion where the fuse clips in can cause a voltage drop,rare but possible.
The ign switch might be a cause. Place BOTH test light and meter on the relay side of the 5a fuse. You should get battery voltage there. If battery is 13.2, you must get 13.2.

 

[TheOldHokie]

Many are so busy arguing about starter type that most all except Lugbolt have overlooked the fact that OP says he can’t get off tractor without it stalling. That means that he has a safety switch problem. Most likely for the PTO which, if so is why his tractor won’t start properly in the first place.

That all came very late in the thread and I did not overlook it. The description is pretty muddled but what he has described so far seems to be correct behavior

• The tractor shuts off when he gets up IF the PTO is engaged.
• The tractor wont crank with his switch if the PTO is engaged

The thread started as a question about potential damage caused by jumpering the starter or so it seemed.

Now it has evolved (devolved??) into a discussion of the cranking circuit, starter relay, and interlocks.

I think a fresh concise and complete statement of the problem including the current operation of the interlocks would be helpful.

Dan

 

[Pau7220]

I am faced with a voltage drop in the circuit that is activated when the main switch is turned to "on." If you review my earlier thread I pasted the entire "starter system check section." I am not going to do it here!.. If a version of the voltage drop test exists that can be used within the starter circuit I have yet to find it. If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

Your question was answered previously….. We’re all trying to help you here. The many videos on YouTube are short and to the point.

As crazy as this sounds, I actually found a bad ground on an Infinity between the engine and trans with a voltage drop test. Multiple trips to the dealer couldn’t find it. A cable between the two cured an intermittent no start.

If it is a wire in the harness, a voltage drop test will find it. A new replacement wire can be run outside of the harness.

Plenty of YouTube videos on this…
The test is always the same … just a matter of where you test the circuit.

Test must be done under a load.

You also need to test for voltage drop from battery to (edit) and through (edit) the ignition switch.

Don’t forget you’re checking for voltage drop, not voltage.

 

[BruceP]

If you know of one used for the starter circuit (NOT THE BATTERY TO STARTER) I would appreciate a primer.

This has been explained to you SEVERAL TIMES by now.

1. Did you PRINT the schematic?
2. Did you use hilighter pen to hilight the circuit in question?
3. Did you clip negative-probe of meter on battery POSITIVE?
4. Did you WRITE DOWN the measured voltages on the printout for each node of the circuit?
   • while key in RUN position
   • while key in CRANKING position

• If not - you are simply not listening
• If you did, please post your findings and perhaps we can tell you where the problem is based on voltages under those 2 conditions at various nodes of circuit.

--------------------------
NOTE: I assume you noted on the schematic that also the GROUND to the starter relay is switched by several safety-switches. HOWEVER: since you said that the 'crank' voltage at the starter was less than battery-voltage, we are ignoring that part of the circuit for now.
BTW: if you measued that while NOT using battery-minus as your reference.... then that also tells us something... but you need to tell us your setup with meter (EXACTLY where each probe is in the circuit)

YOU NEED TO GIVE US SOME MEASUREMENTS AS REQUESTED IF YOU WISH FOR US TO GIVE YOU FURTHER ANALYSIS.

This truly is a trivial problem... I fix several of these per week on all manor of equipment. (mowers, tractors, choppers, trimmers, snowblowers....etc) Anything with electric-start has the same basic circuit with some 'safety switches'.

 

[TheOldHokie]

NOTE: I assume you noted on the schematic that also the GROUND to the starter relay is switched by several safety-switches. HOWEVER: since you said that the 'crank' voltage at the starter was less than battery-voltage, we are ignoring that part of the circuit for now.

Has that voltage difference been clearly established yet? I for one am confused about what voltages have been measured and where.

Dan

 

[Russell King]

[QUOTE="Sparty047, post: Problem I Must FIX has zero to do with the starter motor. IT is that the black lead is NOT delivering battery voltage (due to some very high impedence within the circuit leading to it). Because the Red lead carries 12.7V and the Black only 10.7 (not 12.7) this "starter relay" is NOT activated and does not send on a current to the smaller terminal at the starter motor.
Hope this clears things up!
Thanks.
[/QUOTE]

measure the voltage at the other end of the wire and see if it is 10.7 volts before it is in the wire. If it is 12.7 volts at one end and 10.7 volts at the other end then you have 2 volts dropped off in that wire. There might be a valid reason that the 2 volts is dropping but I didn’t look at the schematics to see if there is anything in the circuit

You know the problem is with that wire so bypass that wire with a new wire connected to the same locations as the existing wire and see if that fixes it assuming that there is not something to drop 2 volts in that wire (resistor for example)

 

[BruceP]

Has that voltage difference been clearly established yet? I for one am confused about what voltages have been measured and where.

Dan

I am confused too Dan.... this is why I asked for specifics regarding location of meter-probes.

We all know that the battery-minus should ALWAYS be used for voltage-readings
and battery-positive used for voltage-DROP testing.... using any other point of reference adds confusion to the results. (like poor ground connection)

 

[GreensvilleJay]

The sad thing is , that in the time it took me to type my msg #50, I could have tested the tractor wiring.
It's a super simple series connection of a relay ,3 switches AND you've got the WSM wiring diagram !

 

[nbryan]

Sounds like the starter motor solenoid is getting energized from the switch but not responding. If there's current flowing through the starter solenoid, even though it's not moving to engage the starter's motor gear and high current starter motor circuit, then there will be a drop of voltage across the solenoid even though it's not moving to engage the starter.

 

[Vigo]

Or better yet install a switch

Dan

Well mechanics often DO have a switch on jumpers of some form or another, either homemade, a ‘starter switch’ which is basically a pistol grip and trigger hooked to two long jumper wires, or a power probe which can be used as such.

But people who don’t diagnose things for a living probably dont have the need for such things often enough to go out of their way and buy or make a ‘real tool’ for rare tasks. So im just saying if one wants to jump something repeatedly for testing and doesnt want to pockmark up the surfaces or make a ‘real tool’ they can just make the final connection on a sacrificial bit of copper wire rather than on their tractor. If anyone does want to buy a premade tool you can get a ‘starter switch’ or power probe for about $20 on the cheap end.

 

[TheOldHokie]

Well mechanics often DO have a switch on jumpers of some form or another, either homemade, a ‘starter switch’ which is basically a pistol grip and trigger hooked to two long jumper wires, or a power probe which can be used as such.

But people who don’t diagnose things for a living probably dont have the need for such things often enough to go out of their way and buy or make a ‘real tool’ for rare tasks. So im just saying if one wants to jump something repeatedly for testing and doesnt want to pockmark up the surfaces or make a ‘real tool’ they can just make the final connection on a sacrificial bit of copper wire rather than on their tractor. If anyone does want to buy a premade tool you can get a ‘starter switch’ or power probe for about $20 on the cheap end.

A remote starter switch at Harbor Freight is $12. I would imagine you can still buy one at just about any auto parts store. In the old days when we adjusted valves and set timing just about every shade tree mechanic had one in his box.

Dan