[ron318]

My 318 ran out of gas while mowing the other night. I shut the pto off, shut the motor off, refilled with gas and suddenly there was no response when I turned the key. No clicking, no response at all. I have since replaced the key switch and installed a new battery (needed one anyway) but still no response. I have found that a starter improvement kit was installed by PO. I have tested various locations and found there is power at the starter and in the smaller red wire between the starter and improvement kit relay. There is no power on any of the other wires in the relay. I found that I could get the tractor to turn over when using a jumper wire between the red wire and the other small wire that goes to the starter solenoid. I think this confirms that the relay is bad. Any thoughts on this one?

 

[chuckv]

Ron,

Here is the wiring that is supposed to be on the starter improvement kit, followed by the original wiring before a kit is installed...

If there is no voltage at the starter improvement relay terminal 85 when the key is in the START position then the issue is in the safety circuits shown in the second drawing. (If your 318 is newer than SN 600,305 you should have the parking brake switch and the parking brake must be set to crank the engine.) Trace the voltage all the way back to the key switch to find which safety switch contact set is not allowing the relay to get pulled in.

If you have now power anywhere, you may also have a failed circuit breaker or bad connections there...

2. If voltage *is* getting to the starter improvement relay pin 85 when you turn the key to the START position, then the relay could indeed be bad.

Chuck

 

[ron318]

Thank you. I have been continuing to investigate. At the ignition switch, there is power coming in, but in the START position there appears to be no power leaving the switch. It's a new switch I bought yesterday. Could the switch be bad?
I think I have confirmed that the neutral switch is working properly. Mine is an '87 so it does not have the brake switch. Where is the safety switch for the front PTO - in the switch itself? Also, where is the circuit breaker located? Thanks for your help.

 

[ron318]

Problem is solved! PO had installed a 20 amp fuse in one of the wires leading to the switch. The fuse was blown - put in a new one and she purrs like a kitten!

 

[7579lincoln]

My 87 316 has the starter improvement relay, but lately when trying to start the engine, the starter just spins, but does not engage the flywheel. After turning the key 4 or 5 times, it usually engages and starts, but sooner or later this will not work. I think the Bendix drive may be bad or dirty or possibly the relay is bad. Any thoughts on what the problem is would sure be helpful. Thanks

 

[jdgreen]

Harvey, Check your starter to see if it is loose. I have also had this problem and found that the screws that hold the Bendix in place have worked loose. If this is the case, make sure you add some locktite to the threads to hold them in place.

 

[7579lincoln]

That definitely could be a possibility. Can this be done without unbolting the engine and removing the starter? Thanks for the idea Bob.

 

[7579lincoln]

I found the problem: it was a bad starter solenoid. I had my starter rebuilt and replaced the solenoid and everything works normally now.

I have another issue with my other 318: believe it or not, the starter solenoid went out on that one too. I had that starter rebuilt and replaced the solenoid and it starts fine, but when I move the speed lever out of the neutral position, the engine dies. I am thinking that when I removed the engine or drive shaft to service it, I may have knocked a wire off somewhere or reversed some wires when putting it back together. I don't know if the ignition is being shorted out somehow or if +12 volts is being removed from the ignition, but think it is one or the other causing the problem. I will try to get more information tomorrow. Any ideas out there?

Harv

 

[jeff_kluewer]

Check your fuses.

 

[gene_cunningham]

If the engine dies when you move from neutral it might be a safety switch problem. I know mine dies if I bounce out of the seat while driving... Just a thought.

 

[chuckv]

Harvey,

The second diagram in my post above #7571 on June 28th shows all the series switches involved in the safety circuit for cranking the engine. The safety switches for keeping the engine supplied with spark is a bit different and is shown below.

What is not shown explicitly in this excerpt is that there is a bypass to keep the ignition hot when the tractor is in neutral, but look at the note on terminal S1 of the key switch which shows the #710 purple wire coming from the brake switch (or neutral switch on earlier tractors. As long as voltage is supplied from the neutral switch to terminal 7 of X23 on the TDCM, the seat delay is bypassed and the engine will continue to run.

Since yours is stopping when you take it out of neutral (and the same would be true if you turned on any PTO switch...) we can surmise that your seat switch is bad, the wiring to that switch is open or grounded, or you have a bad fuse at F2. Another thing to look for is if your tractor is old enough to have the earlier glass cylindrical fuses and the plastic tubular holders -- those holders are notoriously unreliable and should be upgraded to the later tab type automotive fuses as found on the later tractors.

Let us know what you find...

Chuck

 

[7579lincoln]

I found the problem and it was the seat switch connector was not pushed all the way into the connector on the bottom of the seat. Thanks for all the help. I knew it had to be something I did, but I didn't expect it to be something like this. I guess one should quit working on a project when he gets tired!

Harvey

 

[chuckv]

Harvey,

Good to know that you are back in operation! As usual, electrical troubleshooting is 90% or more just finding the issue, and 10% or less addressing it. At least it was a zero dollar fix...

Chuck