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weicm3
11-07-2009, 12:40 PM
Hi,

The mower has been working fine thru the summer but about 1 month back, I couldn't get it started due to low voltage(was showing 9.x on the mower's voltage meter). So, I put the booster battery on and I could jump started it at that time. A few days after I tried to start it and it worked fine. But today I tried to use it, it wouldn't start again. I slow charged the battery to 12.5V but when I turn the key to on, the voltage meter shows 9.5-10.0 immediately. It didn't even click when I turned the key to start position.

When I turned switch off and measured voltage at terminals, it still showed 12V. But once I switch it on, the voltage dropped. I cleaned all the ground points I could find but was still the same. And I couldn't even jump start it. The voltage meter on the booster would drop to the same reading showing on mower's voltage meter.

Does that mean the battery is dead? If so, why it still shows 12V at terminals after I turn the key off? And if it's battery, I should still be able to jump start it, right? Or do I have a bad solenoid? How do I further troubleshooting it?

Thanks in advance!

Restrorob
11-07-2009, 03:22 PM
Battery has a blown strap or is shorted, In either case they will show voltage until a load is applied.

Replace the battery then check the charging system.....

weicm3
11-07-2009, 06:57 PM
Battery has a blown strap or is shorted, In either case they will show voltage until a load is applied.

Replace the battery then check the charging system.....

But if it's battery issue, why jump start didn't work this time? The voltage meter on my booster battery showed the same reading(9.x V) after I switch the key to on position. I kind of suspecting starter solenoid but don't know how to test them to isolate the problem.

Restrorob
11-07-2009, 07:39 PM
OK, What's the voltage drop with the key in the start position ?

weicm3
11-07-2009, 09:52 PM
OK, What's the voltage drop with the key in the start position ?

here are the readings.

key off: 12.4V (measure thru multimeter at battery posts)
key in on/run position: 10V (voltage meter on mower. measured with multimeter at posts and it's the same 10V.)
key in start position: 9.5V (voltage meter on mower)

one thing I found might or might not be related is that if I sit in the seat (there is a seat safety rely in this mower), I could see the voltage reading went from 10V to 10.1V.

Restrorob
11-07-2009, 10:51 PM
Post the full model number off the white label.


Sound like you have more than one problem, It shouldn't be dropping almost 2.5 volts just turning the key on. It shouldn't drop more than 9.5 in the start position while the starter is spinning putting a load on the battery, Which it isn't from what you explain.


So, If the solenoid isn't clicking when you turn the key to start position I would suggest checking the parking brake safety switch first, Once the non clicking solenoid is solved the rest can be checked.

weicm3
11-08-2009, 01:52 AM
I don't have the model number right now. It's out in the shed and it's cold and dark now. I have been reading this service manual online (http://www.mymowerparts.com/pdf/Cub_Cadet/Cub_Cadet_Service_and_Repair_Manuals/Cub_Cadet_RZT_Series_Zero_Turn_Service_Repair_Manual.pdf) This is the exact mower I have and wiring diagram is in this document.

The parking brake safety seems fine because I can see the red light on the console when parking brake is engaged. (and goes away when it's released)

The voltage drop from on to start position was about 0.5V (10V->9.5V)

What could be the reason that causes voltage drops when turning the key to on position?

Restrorob
11-08-2009, 10:52 AM
The brake switch has double contacts inside, Just because you have a idiot light showing doesn't mean the switch is working properly. You have to start someplace and that's where I suggested, The switch can be tested with a multimeter set on ohm's scale. You also have the brake switch relay, Try swapping it with the pto relay and see if you can get the starter to click.


From past experience I just have to ask; You do have the pto switch turned off correct ?

weicm3
11-08-2009, 12:33 PM
The brake switch has double contacts inside, Just because you have a idiot light showing doesn't mean the switch is working properly. You have to start someplace and that's where I suggested, The switch can be tested with a multimeter set on ohm's scale. You also have the brake switch relay, Try swapping it with the pto relay and see if you can get the starter to click.


From past experience I just have to ask; You do have the pto switch turned off correct ?

yes. the pto switch is off when I tried to start the mower and it seems functioning properly as I can hear the click sound when I switch it on and off.

I'll spend sometime today to try the brake switch.

weicm3
11-09-2009, 01:25 PM
yes. the pto switch is off when I tried to start the mower and it seems functioning properly as I can hear the click sound when I switch it on and off.

I'll spend sometime today to try the brake switch.

I didn't have time to play around with the relay yesterday. But found something weird. When I first turned the key to on position to get the voltage reading and it surprisingly showed 12V and the battery warning light was no longer lit.

So, I thought it would start up. Jumped on the seat and ready for a start. But as soon as I turned the key to start position, no click, no sound, nothing and voltage meter showed reading at 9.5V again. :confused:

Then I let it rest for a couple minutes by turning the key to off position. When I turned it to on position again, it showed only 10V. Does it mean my switch(key) or solenoid is going south? Seems something was drawing voltage once key is turned to start position.

edit: I did try to put my finger on the brake relay and could feel a click when the parking brake was engaged.

Restrorob
11-09-2009, 06:45 PM
Well weicm3,


So far I've tried to lend a hand in getting this machine to start, So far you have tried/done nothing I've posted.

What I've posted thus far is exactly how I would handle this no start situation if you had brought this machine to my shop for repair.

The first thing to do would be check/LOAD test the battery (take the battery out and to someplace and have this test performed), If it does in fact pass this test (I have reason to believe it won't) move to the brake safety switch test. If it passes the test then install another/different brake switch relay (easier to swap than to test).


Until these steps are taken and these parts eliminated as being faulty all were doing here is playing a guessing game......

Hopefully while performing all the above you will stumble across the faulty part and solve the problem.

If not, Then post the test results and we'll go deeper into it at that time.


Good Luck

weicm3
11-16-2009, 01:31 AM
Restrorob,

I finally got some time to work on the issue this weekend. The brake switch test didn't help. I also thoroughtly checked all ground connection and all looked good. (took each off, gave a good cleaning, and tightened them up.) Still, voltage dropped while trying to start the engine. No sound and no click from starter motor. Battery is off now and will have it load tested sometime this week.

Found something that might be related though. I found the gear(bendix?) on starter motor is stuck on the flywheel. I took the shroud off and turned the flywheel a bit by hand. The gear on starter would retract. Then I tried to jump start directly on starter motor. Gear would engage flywheel and turn about 1 inch in radius. Then it stuck on flywheel again and made whining sound. Does it mean my starter motor is bad? Or it's just my booster battery doesn't have required cold crank amp?

Restrorob
11-16-2009, 08:26 AM
my booster battery doesn't have required cold crank amp?


That would be the case, The battery is so small in these booster/jumper boxes. They are designed to enhance voltage in a low larger battery to get something cranked, Not take all the load from jumping direct or going through a bad battery.

Restrorob
11-16-2009, 08:41 AM
BTW,

The starter drive is hanging up most likely because there's not enough battery voltage to run it through it's cycle.....

When buying a replacement battery for this unit don't pinch pennies and get a 175 CCR battery, This unit should have 250 CCR or above for proper operation.

weicm3
11-16-2009, 10:22 AM
BTW,

The starter drive is hanging up most likely because there's not enough battery voltage to run it through it's cycle.....

When buying a replacement battery for this unit don't pinch pennies and get a 175 CCR battery, This unit should have 250 CCR or above for proper operation.

Thanks! I'll send in the battery for a load test as soon as I can. Might grab a new battery as well. I think my local HD sells interstate battery (about 350CCA or so rating) for $40-$50. Are they good?

They also have a cheaper one going for $20 something(forgot the brand) but I guess you get what you pay.

Restrorob
11-16-2009, 10:36 AM
interstate battery (about 350CCA or so rating) for $40-$50. Are they good?



Without a doubt, We were a Cub dealer and I don't recall seeing their original equipment battery lasting over a year. In fact, Some had to be replaced before we could even sell the units.

weicm3
11-16-2009, 08:24 PM
okay. got sometime to play with it again this evening. took the battery to local auto store and had it load tested. machine said it has bad cell and battery is no good. so, I picked up an interstate battery from HD and put it on. Turned key to on position and meter showed 12.4V. Happy for a moment and was hoping to hear engine roaring sound when turning the key to start but still nothing happened(no click and no whining). :(

Voltage meter showed a drop to 11.4V when I turn the key to start position. Maybe try to hook up batter directly to starter and see if it makes engine turn? Any suggestion?

Restrorob
11-16-2009, 08:48 PM
machine said it has bad cell and battery is no good.


Hmmm.......


So you have more than one problem now,


Does the PTO clutch engage with the key in the run position ?

Set your multimeter to DC volts, Check for battery voltage on the small spade wire on the solenoid while the key is in the start position.

If voltage is present on this wire replace the solenoid.

If voltage in not present on this wire swap the center PTO clutch relay with the seat relay, Check again. If still no voltage swap the PTO relay with the brake relay. Hopefully by now you will have stumbled across the problem.

weicm3
11-16-2009, 11:32 PM
Does the PTO clutch engage with the key in the run position ?

maybe it's a dumb question. how do I know if PTO clutch engages when key is in run position? click sound? I don't hear any sound when I switch to run position but with key in run position, I can hear metal clunk sound when I pull PTO switch up. (I also saw a small metal piece moving in the PTO clutch.) Is that what you're asking?

I measure the voltage on the spade wire and it shows 11.3V. (matches the reading on voltage meter on the mower) Is it supposed to get full battery voltage(12.3V) to throw power to starter motor?

weicm3
11-17-2009, 01:01 AM
I tried to bypass the solenoid by using screw driver to connect 2 big terminals(with red cables) on solenoid. Starter motor would turn engine fully.

I then used screw driver to connect the terminal with battery positive cable and the small terminal that spade connect goes on. There is a click sound(I think it's from solenoid) but starter motor does not turn.

So, does it mean the solenoid is bad? But I don't know why I got only 11.3V on the spade wire. Seems to me something else is eating up 1V. Does it mean besides battery and solenoid, I have 3rd problem? I think my mower is cursed... :(

Restrorob
11-17-2009, 06:51 AM
So, does it mean the solenoid is bad?

That would be my guess, Don't worry about a 1v drop. It's energizing the relays and most likely a fuel cut off solenoid.

weicm3
11-23-2009, 09:10 AM
Some update here.

Mower back on service yesterday. Replaced the solenoid and it starts right up now. New battery was 12.3V and it's charged to 12.9V after some mowing time.

Restrorob, thanks a lot for your help!

Restrorob
11-23-2009, 12:00 PM
Thanks for the thread update ! Thumbs Up