Can anyone spot a common cause for my electrical issues?

[dkbswim]

Not sure what A, B and C refer to. Perhaps post a picture of the wiring diagram so you can get some good answers.

Replace the suspected relay and see what happens. Then you will know if your conclusion that the relay is the culprit is justified or not.

Easy to do and might save a lot of speculation. AND if it is not the problem, at least you will have a good spare relay for future use...

 

[dclauria]

I did not read every post but recently I've been having a problem where the starter does not engage and all it is is the low voltage connection on the starter is loose, so I just have to dismount, make sure the connector on the starter is firmly seated and all is good.

 

[Sparty047]

thank you Henro and Jay....good advice. I have the part arriving Friday (tomorrow) and can return it if it looks hinckey. You've given me good alternatives. Thanks

 

[Sparty047]

Well sir, I received the starter relay about an hour ago. Measured resistance across terminals A and B measured 79.5 ohm on my el cheapo multimeter which confirms 80 ohms factory specs. (Remember the original was measuring only 10 ohms and with applied voltage chattered and there was no continuity across terminal C and D = FAULTY)

I applied 12 V across A and B and C and D showed continuity.....we have a winning starter relay that is a replacement for the original.

Recall that everything I tested in the engine starting system beginning on page 9-S9 in the KISC shop manual had checked "OKAY" until I got to the starter Relay.

On the starter motor I only measured the voltage between the B terminal and chassis to verify it matched the battery voltage. I did not remove the starter from the engine to perform the motor test as I had put in a new OEM motor in June and starting had been no issue until last Saturday.


SOOOOOOOO....

I sat in the seat depressed the clutch and with PTO in "off" position and my foot off the HST pedal I turned the key anticlockwise to verify preheat (check), turned clockwise to verify panel lights lit up (check) then turned the key fully clockwise to engane the starter circuit and.........
"Click" but no starter motor turning.

This is exactly where I started from......

THE ONLY ANOMALIES I FOUND WHEN I RAN PERFORMANCE TESTS WAS THE FAULTY STARTER RELAY (NOW REPLACED) AND THE FACT THA, AT THE CONNECTOR FOR THE STARTER RELAY, I MEASURED 12.49 ACROSS THE C TERMINAL (SAME AS BATTERY) AND ONLY 10.89 ACROSS THE A TERMINAL WITH THE SWITCH IN THE START POSITION (NOT the battery 12.49)!

Shop manual states that if the voltage is different from battery (as is my case), "slow blow fuse, wiring harness and main switch is faulty". I would think this a typo with that "and" to be an "or".

Since the A terminal on my starter relay harness is NOT the same as battery with switch on, "either my slow blow fuse, wiring harness, or main switch is faulty".

I already checked the switch. Can anyone verify which of the two fuses is considered to be the "slow blow fuse"? I'd like to replace that fuse before stripping down the insulation wrap to inspect and then replace the wiring harness for the starter relay connector!!

I would welcome any other suggestions.

 

[Sparty047]

I did not read every post but recently I've been having a problem where the starter does not engage and all it is is the low voltage connection on the starter is loose, so I just have to dismount, make sure the connector on the starter is firmly seated and all is good.

Just spotted your reply....thanks for this information.....are you saying the B terminal on the starter can be loose or are you referring to the other terminal that clips into place? Thank you.

 

[DrankTheOrangeKoolaid]

THE ONLY ANOMALIES I FOUND WHEN I RAN PERFORMANCE TESTS WAS THE FAULTY STARTER RELAY (NOW REPLACED) AND THE FACT THA, AT THE CONNECTOR FOR THE STARTER RELAY, I MEASURED 12.49 ACROSS THE C TERMINAL (SAME AS BATTERY) AND ONLY 10.89 ACROSS THE A TERMINAL WITH THE SWITCH IN THE START POSITION (NOT the battery 12.49)!

Perform positive and negative voltage drop tests. That will help identify why you only have 10.89V at the starter.

 

[North Idaho Wolfman]

So you turn the key and get a Click ( relay ) or a clunk (starter solenoid)?
if it's a click then it sounds like the relay is engaging, check for voltage on the small terminal (solenoid power) at the starter with a meter or test light.

 

[Sparty047]

Perform positive and negative voltage drop tests. That will help identify why you only have 10.89V at the starter.

Looks like the voltage drop test is carried out with the starter cranking. Is there a way to check under my current conditions?

 

[Sparty047]

So you turn the key and get a Click ( relay ) or a clunk (starter solenoid)?
if it's a click then it sounds like the relay is engaging, check for voltage on the small terminal (solenoid power) at the starter with a meter or test light.

will do tomorrow...thanks. It's definitely a click. Am I correct to assume the voltage check on the smaller starter terminal is performed to chassis with someone turning the key? Or is it done with ignition in the off position?

Sorry for my lack of Kubota experience...my mechanical acumen was gained as a respiratory therapist modifying ventilators back in the old days to make them perform better than when they were sold to us. lol I seldom did anything more complicated to my auto engines then plugs and wires; or adding a oil catch can to my 2.8L deisel. I actually have learned a great deal about the engine start system and safety switches. Can't say enough positive things about the folks in this forum. Just a great bunch!!!!

 

[Oil pan 4]

Starter relays usually don't go bad. I say replace it with something bigger and locally available.

 

[DrankTheOrangeKoolaid]

Looks like the voltage drop test is carried out with the starter cranking. Is there a way to check under my current conditions?

The test should work when you turn the key to start. I was in the same situation back in September. Had a relay die and when I replaced it, the starter still would not crank. The voltage drop test found my problem.

My thanks to Dave_eng

Dave_eng has posted the Denso voltage drop test several times. Today it saved me a lot of time and some of the few remaining hairs on my head. Last week, I went to start my M6800, it turned over and just before it started there was a loud pop and nothing. I tried again and all I got was some...

www.orangetractortalks.com

 

[Sparty047]

View attachment 90301

Here's where I am: (see above):

1) Connector Voltage
3. = batt voltage =OK
4. was ~ 1.5 V lower = Fail But switch, batt & slow fuse all checked OK

2) Starter relay failed (3.4) so replaced.

But still no crank !!!


With starter relay removed:
Refer to diagram:
I can turn on main switch; and momentarily jump from A to C to engage starter.
Tractor immediately starts and runs just fine!

Runs until I stand up, or turn switch off. (Let's call this jump start)


Began tracing wiring back from Rely Connector (unwrapping and inspecting) with intermittent trials of turning switch with and without the relay in place. Along with this I switch out the slow blow fuse the starter relay and glow plug fuses ("just because it was easily done").

At about the third trial, switch starting position failed to produce any measurable voltage at term A! I could still jump start the tractor. But now I measure 0 V at term A and not 10+V!!

SO:

For $25 I have ordered a new main switch that will arrive in a couple of days!

The only alternative is to continue unwrapping and inspecting the wiring harness (which so far
has appeared clean, uncrimped, no scrapes, etc).


ANY COMMENTS?


BTW....I have some hearing issues, so can hear the distinctive "click" but can't localize it. Seems to come from behind the "dash" but where and what is it that "clicks"?

 

[ve9aa]

I didn't read every reply.\
Did you LOAD TEST just your battery somehow?
Measuring battery voltage with nothing running is only one part.
They can let you down when the going gets tough (think, starting a car in -30 below weather)

 

[Sparty047]

I didn't read every reply.\
Did you LOAD TEST just your battery somehow?
Measuring battery voltage with nothing running is only one part.
They can let you down when the going gets tough (think, starting a car in -30 below weather)

thanks taking note. Battery cranks starter just fine when I jump start so it passes load testing.

 

[leveraddict]

Did you check the crappy plug going to the alternator?

 

[ve9aa]

OK, but I really meant actual "load testing" as in putting on a heater type current measuring device attached such as:
MotoMaster Battery Tester, 100-Amp Load, 6V/12V | Canadian Tire

The cranking you did may reveal SOME issues but isn't exactly the same.
The same can be said for a plain old voltmeter. You could measure 12.7VDC at rest
at the battery, but once you get cranking it may drop way waaaay down as current load
increases.

Again, I didn't read every post, but it might sound like a poor/high resistive connection somewhere.
(not neccesarily visible or accessible.)_ First check would be ground lugs, connections to battery etc. and only once I was sure it wasn't that, would I even think about throwing money at the problem.

good luck sorting it all out OP !

 

[Sparty047]

OK, but I really meant actual "load testing" as in putting on a heater type current measuring device attached such as:
MotoMaster Battery Tester, 100-Amp Load, 6V/12V | Canadian Tire

The cranking you did may reveal SOME issues but isn't exactly the same.
The same can be said for a plain old voltmeter. You could measure 12.7VDC at rest
at the battery, but once you get cranking it may drop way waaaay down as current load
increases.

Again, I didn't read every post, but it might sound like a poor/high resistive connection somewhere.
(not neccesarily visible or accessible.)_ First check would be ground lugs, connections to battery etc. and only once I was sure it wasn't that, would I even think about throwing money at the problem.

good luck sorting it all out OP !

As you state, you did not read all the posts. The issue is failure of ignition system to send a signal through to the starter motor!

If I bypass the circuit for the starter relay the tractor will "jump start" with gusto. Therefore the battery is not the issue. I have a device built with a 400 w converter and fluorescent light fixture to do load tests. I feel no need to load test it. Thanks for your concern and input.

 

[Sparty047]

Did you check the crappy plug going to the alternator?

Yuppie! Been there, done that......(it is crappily lightweight...lol)

 

[dclauria]

Just spotted your reply....thanks for this information.....are you saying the B terminal on the starter can be loose or are you referring to the other terminal that clips into place? Thank you.

Sorry - I know it's been a while - just spotted your reply. Not the battery cable, but the ignition connector on the starter. It's happened a few times now. Eventually I will have to take a quick look at it, but for now every time it happens, I just wiggle or push on the coil connector and it starts right up.

 

[fried1765]

OK, but I really meant actual "load testing" as in putting on a heater type current measuring device attached such as:
MotoMaster Battery Tester, 100-Amp Load, 6V/12V | Canadian Tire

The cranking you did may reveal SOME issues but isn't exactly the same.
The same can be said for a plain old voltmeter. You could measure 12.7VDC at rest
at the battery, but once you get cranking it may drop way waaaay down as current load
increases.

Again, I didn't read every post, but it might sound like a poor/high resistive connection somewhere.
(not neccesarily visible or accessible.)_ First check would be ground lugs, connections to battery etc. and only once I was sure it wasn't that, would I even think about throwing money at the problem.

good luck sorting it all out OP !

That little 100amp carbon pile load tester from Canadian Tire ain't much!
Amazon (USA) sells the "Clore" brand 500 amp carbon pile tester for $77.98 USD , and it is a much more capable tester.