TC35 Operator Safety Module

[allen_shelton]

Hello all. I've got a new to me TC35 that won't start. It's not getting voltage to the the fuel solenoid. So I verified the relay is good and probed the connector and found out I'm not getting a ground on the connector. I can ground a piece of wire and stick it in the bottom of the relay connector and it'll start up. I traced out the wire and it goes to a module with two other wires on the left side of the tractor. The wiring diagram calls this the operator safety module. It looks like all it does is give a ground to the seat switch and the solenoid relay. It makes me wonder that, if that's all it does then why didn't they just tie all three wires together instead of running them through that module? It was full of crud but cleaning it out and shining up the contacts on the module did nothing. I also jumped the seat switch...no change. So, does the safety module have some other function that I'm missing?

 

[Midniteoyl]

Disclaimer: I dont have a New Holland or the manual..

Hard to tell with that one page, but usually the PTO and Neutral switch, if not also the Parking Brake switch, or all encluded in that circuit. They can be daisy chained or all go separately to that Safety Module but either way it's all one big AND logic circuit and they all need to being working. Follow the wiring diagram and see where those wires go off page..

 

[Hughman]

Check the #2 fuse in the fuse block on the firewall under the hood.

 

[allen_shelton]

Yeah, fuse is good. I've got voltage at the relay, just no ground to enable the relay to work. I was just wondering what exactly the operator safety module does. I've got no continuity across the pins on it so I'm either going to get a new module or tie the wires to ground.

 

[grsthegreat]

The schematic is hard to see close up, but what is the device between ground and fuel solenoid. Its a rectangular box with a line thru in, just above the ground. I cant read the symbol telling whet it is. Certainly it cant be a fuse between solenoid and ground, but almost looks like a fuse or resistor symbol.

 

[chris.benjamin1]

The safety module takes into effect where the PTO selector is at plus all of the operator controls range selector to confirm if that ignition is a go. One page in operators manual explains the combinations of control settings and their outcomes

Keep it functional. One of the circuits has an issue more than likely

 

[thclimer]

Here is the full electrical schematic and a description and test instructions for the Operator Safety Module.

 

[DBradby]

Did you ever get your problem figured out? I’m having the same problem now. The operator safety module tested bad but all of the relays tested good. I’m not getting power to the fuel solenoid or started solenoid. But I can hot wire the solenoid and then jump the starter and it fires right up and runs normally until I remove the hot to the solenoid. Just wondering what you found.