CUB RZT 50 won't start

   / CUB RZT 50 won't start #1  

Bentbarz

New member
Joined
Feb 8, 2012
Messages
14
Location
Gray Court, sc
Tractor
Mahindra 5035 HST
I have been banging my head against the wall with this one. It is a 2004 with the 22 HP b&s engine. Mowed with it, put it up and it would not turn over. Tried jumping it, nothing. Started digging and figured the starter solenoid was shot since the PTO would engage and brake indicator light would come on. Bought two, tried them both including cleaning up the ground connections...nothing. I can start it just fine with a screw driver across the solenoid terminals, and it runs fine. I have put a meter on all of the safety witches and even bought a new seat switch and neutral switch just in case I was missing something. Checked and replaced the fuse. I have taken off all the connections and put then back on (most multiple times). I have power on pin 86(might be saying wrong number, but per the manual it is right) of the brake relay, which if. Read the service manual correctly means than all three relays are working for the power to make it that far. I can feel all three relays "clicking", so again I think they are ok.

Here is my fundamental question. If I have battery power coming into one leg of the starter solenoid, and control voltage at the top, should it be putting power out to the starter? I just don't think the control voltage would ever make it to the solenoid if there was anything not right in the starting circuit. If that is the case, the. Am back to my original assumption that the solenoid must be bad, but two new ones...seems hard to believe.

Help!!!

Travis
 
   / CUB RZT 50 won't start #2  
sounds very much like a defective ignition switch. chk for 12vdc going to small lead into starter relay solenoid when switch is turned to "start" - if no 12 vdc, you either have an open in that wire from the ign switch or the switch itself is defective.
PS: take before pix if taking wires off ign sw and only replace with OEM sw - not all aftermarket sw work the same.
 
   / CUB RZT 50 won't start #3  
I have been banging my head against the wall with this one. It is a 2004 with the 22 HP b&s engine. Mowed with it, put it up and it would not turn over. Tried jumping it, nothing. Started digging and figured the starter solenoid was shot since the PTO would engage and brake indicator light would come on. Bought two, tried them both including cleaning up the ground connections...nothing. I can start it just fine with a screw driver across the solenoid terminals, and it runs fine. I have put a meter on all of the safety witches and even bought a new seat switch and neutral switch just in case I was missing something. Checked and replaced the fuse. I have taken off all the connections and put then back on (most multiple times). I have power on pin 86(might be saying wrong number, but per the manual it is right) of the brake relay, which if. Read the service manual correctly means than all three relays are working for the power to make it that far. I can feel all three relays "clicking", so again I think they are ok.

Here is my fundamental question. If I have battery power coming into one leg of the starter solenoid, and control voltage at the top, should it be putting power out to the starter? I just don't think the control voltage would ever make it to the solenoid if there was anything not right in the starting circuit. If that is the case, the. Am back to my original assumption that the solenoid must be bad, but two new ones...seems hard to believe.

Help!!!

Travis

Did you run thru the safety interlock checklist to make sure everything is doing what it suppose to.

http://www.cubcadet.info/Manuels/2005/Tracteurs/RZT50-Owner.pdf

Hot wiring the solenoid shows it still works. Most safety switches have to be pushed IN for the starting circuit to work. As in CONTROL ARMS FULLY OUT, SITTING IN SEAT, BRAKE LOCKED, PTO OFF. The safety switch came loose on mine from the control arm thus the mower was dead in the water. Look for the obvious.
 
   / CUB RZT 50 won't start #4  
Sound like one of the several silly safety locks is either broken, come loose, ...or forgotten by you:)

The machine is barely usable until those locks get bypassed.
 
   / CUB RZT 50 won't start
  • Thread Starter
#5  
Keep the ideas coming...

Have checked all of the safety switches and am very familiar with the starting requirements.

With respect to the ignition, I do have 12v to the small terminal on the starter solenoid (control voltage). It seems to me that if I have 12 volts there, and incoming power from the battery, it should turn the starter over. The solenoid never pulls in though. I really think I might have gotten two bad parts to replace my failed part as hard as that is for me to believe.
 
   / CUB RZT 50 won't start #6  
Keep the ideas coming...

Have checked all of the safety switches and am very familiar with the starting requirements.

With respect to the ignition, I do have 12v to the small terminal on the starter solenoid (control voltage). It seems to me that if I have 12 volts there, and incoming power from the battery, it should turn the starter over. The solenoid never pulls in though. I really think I might have gotten two bad parts to replace my failed part as hard as that is for me to believe.
If you jump out all your safety switches then you have a basic starting circuit. You should have a charging circuit to keep the battery up. Assuming you have checked that out with a volt/ohm meter. Then move on to the starter circuit. Ignition switch usually has an ON/START. Just like a tractor the switch sends voltage to the coil (- side) in the RUN position. The momentary start is what bumps the starter when you hold it and springs back to RUN. Disconnect the battery and Ohm out the wires leading from the ignition switch and make yourself a drawing. Draw the circuit out to get an idea of what goes were. Take pictures before removing any wires to keep from scratching a hairless spot of your head later.

There are many simple ignition wiring diagrams on the net to use as an example. I totally rewired my 135 from scratch with info aquired on the net. That includes adding a conventional auto ignition switch and alternator. Take some gator clips and spin the solenoid to verify. Ignition switches are known to fail, but I'm betting the switch is ok.
 
   / CUB RZT 50 won't start #7  
Keep the ideas coming...

Have checked all of the safety switches and am very familiar with the starting requirements.

With respect to the ignition, I do have 12v to the small terminal on the starter solenoid (control voltage). It seems to me that if I have 12 volts there, and incoming power from the battery, it should turn the starter over. The solenoid never pulls in though. I really think I might have gotten two bad parts to replace my failed part as hard as that is for me to believe.

Travis - that new solenoid you got may need to have a ground for that 12 volt engagement power coming from the ignition switch - try scraping a bit of paint off on the tractor frame where the solenoid mounts to guarantee a ground and see if that new solenoid will energize.
 
   / CUB RZT 50 won't start #8  
remove your key switch look at the back of the switch(usually 5 terminals) one will have a B marked on it for battery and another with a S for starter check to see if you have 12 volts at the B plugin to B switch terminal,if so then you can run a jumper wire from the S plugin side to the small terminal on the solenoid it should then crank (when the plugin is pushed back on the switch)
 
 
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