B7800 solenoid

[BobbyT27]

New to the forum

is there a known issue with the fuel solenoid? Mine is intermittent. Of course it is bloody cold so not sure if that is the issue. Tapped it with a large screw driver and it worked. Do they need replacing? 535 hours on the tractor

 

[Dave_eng]

Usually the problem is in the controls providing power to the solenoid.
OPC for operator presence controller and timer relay being two most common unless a safety switch is faulty thus triggering the proper operation of the OPC. Seat switch would be first to investigate.

Dave

 

[BobbyT27]

Usually the problem is in the controls providing power to the solenoid.
OPC for operator presence controller and timer relay being two most common unless a safety switch is faulty thus triggering the proper operation of the OPC. Seat switch would be first to investigate.

Dave

Thanks.
The tractor turns over though and just will not start unless I hear the click form the solenoid. Will this happen if the OPC is bad?

 

[Dave_eng]

Thanks.
The tractor turns over though and just will not start unless I hear the click form the solenoid. Will this happen if the OPC is bad?

You need to first understand how the engine stop solenoid operates on your tractor.
Some tractors apply power to the solenoid to allow the engine to start.
Other tractors apply power to the solenoid to stop the engine.
I am not where my resource material is so this is a educated guess.

Your solenoid will have two internal coils. A strong PULL-In coil that moves the solenoid plunger and a much weaker HOLD coil that holds the solenoid retracted allowing the engine to run.

It could be that the power for the pull in coil is not working. Check for a blown 5 amp fuse.

Do you have a 12 volt test light. To do any electrical trouble shooting you need one. Less than $20 on line or any auto parts place.

Separate the power connector at the solenoid and test for power on the power connector to the solenoid.

If the connector has two terminals, test each terminal to ground as you turn the key switch from Off to ON to start

Dave

 

[Henro]

In the thread that hopefully the following link takes you to, Dave posted an electrical circuit diagram for the B7800.

This should help you if you are able to read and understand electrical diagrams...

B7800 HST engine shuts down.

My B7800 HST just let me down. It started like normal then shut down after traveling 5 to 8 feet. Restarted right up then shut down again. It always restarts and will run in neutral with no problem. I have since tried it in neutral and it seems to be a problem with movement of the drive control...

www.orangetractortalks.com

 

[BobbyT27]

You need to first understand how the engine stop solenoid operates on your tractor.
Some tractors apply power to the solenoid to allow the engine to start.
Other tractors apply power to the solenoid to stop the engine.
I am not where my resource material is so this is a educated guess.

Your solenoid will have two internal coils. A strong PULL-In coil that moves the solenoid plunger and a much weaker HOLD coil that holds the solenoid retracted allowing the engine to run.

It could be that the power for the pull in coil is not working. Check for a blown 5 amp fuse.

Do you have a 12 volt test light. To do any electrical trouble shooting you need one. Less than $20 on line or any auto parts place.

Separate the power connector at the solenoid and test for power on the power connector to the solenoid.

If the connector has two terminals, test each terminal to ground as you turn the key switch from Off to ON to start

Dave

Thanks Dave. I did check it across the connector. Did not realize it needs to go to ground which makes more sense. Appreciate the advice. All the fuses were good. It just seems like the solenoid gets stuck. Once I banged it it started.

 

[Dave_eng]

Banging should not be a normal requirement if the pull in coil and its power supply are in good order.

Dave

 

[BobbyT27]

Banging should not be a normal requirement if the pull in coil and its power supply are in good order.

Dave

Thanks possibly the coil is failing then

 

[Dave_eng]

Thanks possibly the coil is failing then

It is far more likely you do not have power going to one side of the stop solenoid coil.

Henro posted a link to a previous thread I provided info in. Have you read through it?

Throwing $ without a thorough diagnosis will bring nothing but unhappiness.

Dave

 

[Mark_BX25D]

A bad coil that is hanging up is certainly a possibility, and the only cure for that is a new solenoid.

However, checking the electrical system should happen first. You need CLEAN connections. A tractor that old probably has some grunge. A brass brush may be all you need to fix this. Take the connections apart, and clean them shiny, apply a thin coat of dielectric grease to prevent corrosion, and see if that fixes things.

And of course, check each of the 3.2 bazillion safety switches, as already mentioned.

 

[BobbyT27]

A bad coil that is hanging up is certainly a possibility, and the only cure for that is a new solenoid.

However, checking the electrical system should happen first. You need CLEAN connections. A tractor that old probably has some grunge. A brass brush may be all you need to fix this. Take the connections apart, and clean them shiny, apply a thin coat of dielectric grease to prevent corrosion, and see if that fixes things.

And of course, check each of the 3.2 bazillion safety switches, as already mentioned.

Thanks I will do that.