NH TC30 Stalls When removing Parking Brake or taking it out of Neutral

   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral #1  

js4185

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Joined
May 20, 2024
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10
Tractor
New Holland TC30
I have, what appears to be, a common issue. However, following all other's previous recommended fixes, I still have my issue.

Background: I have a 2004 New Holland TC30. HST. Starts and runs great. I can move the bucket. It will run all day long as long as I don't take off parking brake or take it out of neutral.
Issue: NH TC30 stalls as soon as I take off parking brake or take it out of Neutral (move it to Low, Medium or High).
Fixes tried to date: It appears to part of the safety system, so I jumpered out the seat safety switch, jumpered PTO safety switch and jumpered parking brake safety switch. I have also replaced the Seat Safety Switch Timer. I have also checked all fuses. Note: All jumpers are done temporarily for troubleshooting and will connect all safety switches back up once I get it working.
Request: Before I throw parts at it, I am wondering where is a next place to look? For example: Ignition switch, Kill relay, wiring, etc.
 

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  • NH TC30 Electrical Schematic P1.jpg
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  • NH TC30 Electrical Schematic P2.jpg
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  • IMG_4320 (3).jpg
    IMG_4320 (3).jpg
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  • TC30 Starting Circuit.pdf
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  • TC30 Run Circuit.pdf
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Last edited:
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral #2  
Does it die as soon as you put it in gear, even without letting the clutch out? If so, its probably the weight sensor under the seat, that prevents you from starting it without sitting in the seat.
 
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral #3  
This is my guess, while you have "jumpered" the seat switch I'm thinking there is still a issue possibly with its wiring as its acting like your not in the seat.
 
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral
  • Thread Starter
#4  
Yes, it dies as soon as I take it out of N (move to L or H) or it will die if I take off the parking brake. Also, it will not start without the parking brake on.

Per the operating manual the issues possible and my thoughts:
1. Defective parking brake or seat safety switch - I jumpered both out and got the same results.
2. Defective key switch - I don't believe it is this since it starts and runs great. But I am not sure. I will test this next.
3. Defective neutral or mid PTO safety switch - Both tested and they are ok
4. Malfunctioning fuel shutoff solenoid - I don't believe it is this since it runs.
5. Blown 5-amp fuse - Tested OK
6. Open wiring in safe operation circuit - This is above my paygrade and will require a technician.

Am I missing anything else?
 

Attachments

  • TC30 Start - No Operator Present.pdf
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  • TC30 Start - Operator Present.pdf
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   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral
  • Thread Starter
#5  
Does it die as soon as you put it in gear, even without letting the clutch out? If so, its probably the weight sensor under the seat, that prevents you from starting it without sitting in the seat.
I agree this is best place to start. However, I did jumper out the seat switch. I am able to start the tractor with the parking brake on and not being in the seat.
 
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral
  • Thread Starter
#6  
This is my guess, while you have "jumpered" the seat switch I'm thinking there is still a issue possibly with its wiring as its acting like your not in the seat.
I did not see any damaged wires, but an open in a wire feels logical.
 
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral #7  
Even though you have jumpered out the switch it's wiring might not be sending (cut/open) that signal to it's relay or it's relay is defective. A number of the relays are the same so you can swap them around to see it the problem moves with the defective one.
 
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral
  • Thread Starter
#8  
Even though you have jumpered out the switch it's wiring might not be sending (cut/open) that signal to it's relay or it's relay is defective. A number of the relays are the same so you can swap them around to see it the problem moves with the defective one.
I did test each relay (3 under the seat) and 1 in front (safety start relay) and they passed. But, I do like your idea. I will buy one new relay and then rotate all the relays and note the results.
 

Attachments

  • TC30 Relay Test.pdf
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   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral #9  
I did test each relay (3 under the seat) and 1 in front (safety start relay) and they passed. But, I do like your idea. I will buy one new relay and then rotate all the relays and note the results.
If you have tested them then they are good. This is strange.

Where you placed your jumper are you able to remove it and measure continuity between the terminals?
 
   / NH TC30 Stalls When removing Parking Brake or taking it out of Neutral #10  
I also recall that these relays require a full 12V feed to them before they will make good contact. You might want to double check the wiring and harness connections on the relays.
 
 
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