312-8 issues

[RED-Z06 2,560]

Interesting...your system has 2 small terminals on the solenoid, 1 is 12v hot and one is grounded thru the safety circuit.

[Wheelhorse616 4]

4 minutes ago, RED-Z06 said:

Interesting...your system has 2 small terminals on the solenoid, 1 is 12v hot and one is grounded thru the safety circuit.

What should I fix or change.

[RED-Z06 2,560]

1 hour ago, Wheelhorse616 said:

What should I fix or change.

My man i have no idea, the tests with a multi-meter or 12v test light aren't hard or time consuming, but its not a tutorial im going to spend 30 minutes tapping out on my phone not knowing if everything was put back together correctly.

 

My C100 was disassembled for paint by the previous owner 16 years ago, he got all the wiring wrong on assembly and nothing at all worked..he got frustrated and it sat ever since.

 

5 minutes...thats how long it took with a meter to fix it all and start it...

 

If you dont know how the wiring works, or is supposed to work and how to put together a mental flow chart of how to troubleshoot it from the small hot wire off the always hot post on the solenoid, thru the fuse, up into the ignition switch and thru the harness...you arent likely going to be able to fix it yourself, i get a couple dozen mowers in the shop every year where people have made a mess trying to diagnose a problem and caused hundreds in damage foe a no-cost fix like a loose plug.

[RED-Z06 2,560]

Where does this wire go?  1 end to the fuse block and the other end goes where on the solenoid?

[Pullstart 65,793]

1 hour ago, Wheelhorse616 said:

There’s some pictures, if anyone knows where that wire goes. Feel free to ask for more pictures of any other spot, let me know. Thanks!

 

 

this wire WON’T have anything to do with it running.  We need to confirm that the small wires are positive and ground to the solenoid.  Let’s put the jumper wrench down for now.  Are the safety switches all in the right position?  Clutch pedal down?  PTO disengaged?  Seat switch activated?

 

 

[RED-Z06 2,560]

The red wire on top is what provides all the 12v power to the tractor, everything that gets 12v comes off that wire that goes to the fuse.  We need to confirm that red wire is hooked to the large post on the solenoid that goes to the battery 

[Wheelhorse616 4]

5 hours ago, RED-Z06 said:

The red wire on top is what provides all the 12v power to the tractor, everything that gets 12v comes off that wire that goes to the fuse.  We need to confirm that red wire is hooked to the large post on the solenoid that goes to the battery 

Yes it is is hooked to the large post on the solenoid that goes to the positive side of the battery. 

[Wheelhorse616 4]

5 hours ago, Pullstart said:

 

this wire WON’T have anything to do with it running.  We need to confirm that the small wires are positive and ground to the solenoid.  Let’s put the jumper wrench down for now.  Are the safety switches all in the right position?  Clutch pedal down?  PTO disengaged?  Seat switch activated?

 

 

Yes everything is good.

[Pullstart 65,793]

4 minutes ago, Wheelhorse616 said:

Yes everything is good.

Ok.  Now we need to verify if there is power or not, along with proper ground at those two tabs below.  A $20 meter with DC voltage and CONTINUITY functions will be your best friend for this fix.  We can help you navigate about any meter or even a test light if that’s all you have.  Like mentioned, it could be a switch connection, or a bad switch…. Be it a safety switch or ignition switch.

[Pullstart 65,793]

It could also be a bad solenoid too.  If you have any jumper wires with alligator clips, you could ground the black wire tab to the battery and intermittently tap a positive wire to the positive side.  There should be an audible click and the engine should roll over.

[Wheelhorse616 4]

25 minutes ago, Pullstart said:

It could also be a bad solenoid too.  If you have any jumper wires with alligator clips, you could ground the black wire tab to the battery and intermittently tap a positive wire to the positive side.  There should be an audible click and the engine should roll over.

Power to where, I have power to the positive side of the solenoid and nothing even in the start position for the wire going to the starter. If I “wrench” the two terminals together I can get it to run. I would really like to know where the wire goes to cross that off the list of troubleshooting. I don’t even get lights on the dash when I press test which is odd. I have a new voltage meter in there as well if that helps.

[Pullstart 65,793]

Are you talking the positive side of the coil (small wires) or the load side (big wires)?  I’m talking the coil side… small push on wires.  By meter, I meant a test meter tool, not wired into the tractor.  

[peter lena 9,190]

@Wheelhorse616  have you tried , clamping a battery cable from , battery ground bolt behind dash , to corner of engine to frame bolt ? , would remove Bothe bolts involved , scrape and dielectric grease , worth a try . nothing else is helping out , just an idea , pete

[953 nut 59,252]

13 hours ago, RED-Z06 said:

2 small terminals on the solenoid, 1 is 12v hot and one is grounded thru the safety circuit.

This may be how it is done on some mowers or garden tractors. On a Wheel Horse one of the small terminals is grounded and the other will receive 12 volts from the ignition switch in the start position if the PTO is off and the clutch is depressed and the oil level (if equipped with an oil sentry switch) is at a safe level. Some of the later units employed relays and lighter gauge wiring but that is not the case on this one.

[RED-Z06 2,560]

15 minutes ago, 953 nut said:

This may be how it is done on some mowers or garden tractors. On a Wheel Horse one of the small terminals is grounded and the other will receive 12 volts from the ignition switch in the start position if the PTO is off and the clutch is depressed and the oil level (if equipped with an oil sentry switch) is at a safe level. Some of the later units employed relays and lighter gauge wiring but that is not the case on this one.

So effectively they used a non grounded 2 wire solenoid but didnt change the harness...and a grounded solenoid accomplished the exact same function.  Usually the ungrounded coils utilized the 2nd post as a 2nd safery circuit, only allowing it to crank when a path to ground as well as a 12v feed were both applied 

[RED-Z06 2,560]

21 minutes ago, 953 nut said:

This may be how it is done on some mowers or garden tractors. On a Wheel Horse one of the small terminals is grounded and the other will receive 12 volts from the ignition switch in the start position if the PTO is off and the clutch is depressed and the oil level (if equipped with an oil sentry switch) is at a safe level. Some of the later units employed relays and lighter gauge wiring but that is not the case on this one.

Here is the factory setup on my 87 312, and my [2] 310s with magnums were the same...maybe much later in the run...i dont know, never seen a horse with an ungrounded solenoid 

[Wheelhorse616 4]

27 minutes ago, RED-Z06 said:

Here is the factory setup on my 87 312, and my [2] 310s with magnums were the same...maybe much later in the run...i dont know, never seen a horse with an ungrounded solenoid 

I have a 1990 312-8, it’s a new solenoid and forget if it was grounded before.

[Wheelhorse616 4]

Could I just pull off the connections and test light the two. 

[Pullstart 65,793]

If you can remove the solenoid, or get to the wires easy enough, let’s break this down a bit.  Circled in red is the load side.  Circled in blue is the coil side.  The small wires in the blue circle are a positive and a ground, they energize a coil that connects the big studs together.  If you can remove the small wires from the coil, jumper from the battery straight to those, does it click?

 

If you can do this with it in the tractor, does it roll the engine over?

[Wheelhorse616 4]

4 minutes ago, Pullstart said:

If you can remove the solenoid, or get to the wires easy enough, let’s break this down a bit.  Circled in red is the load side.  Circled in blue is the coil side.  The small wires in the blue circle are a positive and a ground, they energize a coil that connects the big studs together.  If you can remove the small wires from the coil, jumper from the battery straight to those, does it click?

 

If you can do this with it in the tractor, does it roll the engine over?

Before I go try here’s everything I know so far; Here’s what I know 
No power to one fuse
Power to positive top terminal solenoid
Will start when wrenched 
No juice to front lights 

The fuse box could be causing the problem I check it with a test light and got nothing to one of them.

 

It clicks and turns over.

Edited December 28, 2021 by Wheelhorse616

[RED-Z06 2,560]

18 minutes ago, Wheelhorse616 said:

Before I go try here’s everything I know so far; Here’s what I know 
No power to one fuse
Power to positive top terminal solenoid
Will start when wrenched 
No juice to front lights 

The fuse box could be causing the problem I check it with a test light and got nothing to one of them.

 

It clicks and turns over.

So you turn the key and the solenoid clicks and the engine spins?

[Wheelhorse616 4]

3 minutes ago, RED-Z06 said:

So you turn the key and the solenoid clicks and the engine spins?

I turn the key skip the solenoid to only the two on the load side connected and it starts.

 

[RED-Z06 2,560]

Figure out the dead fuse, on mine i believe one is for the chassis power and one is for the charging system.

[killroy 36]

Sounds like no voltage to the ignition system.  

[953 nut 59,252]

9 hours ago, killroy said:

Sounds like no voltage to the ignition system.  

A  1990 312 has a magneto ignition system and produces its own power.