BX23S Low voltage on wire to starter solenoid

[Micawber]

Hello — I’ve been troubleshooting an issue with my BX23S and could use some guidance. The tractor was running normally, then suddenly stalled as if a safety switch opened. When I attempted to restart it, the starter would not engage at all.

I went through all of the safety switches, and they appear to be functioning properly. I checked voltage at both seat switches and confirmed continuity on the PTO switch. Earlier this year I had a similar issue, and I added a starter-assist relay. I tied the Black/White starter-solenoid wire into the relay coil and fed battery voltage through the relay contacts. This seemed to be a common workaround and it had been working well.

Here’s what I’m seeing now:

• If I disconnect the Black/White wire from my added relay, it reads 12V when I turn the key to “start.”
• As soon as I connect it to the relay, the voltage drops to about 4V.
• I replaced the relay, but the readings are the same.

I’m not completely certain where the Black/White wire originates inside the tractor. From the schematics, it appears there is an OEM start relay in the circuit. Under the fuse box I see two relays mounted together — one of them enclosed in a rubber boot.

Given all of this, what do you think the most likely issue is?

 

[whitetiger]

By adding your relay, you accomplished nothing more than making the original failing relay feed an unnecessary one.
The original relay is under the top part of the dash on its RH side.

 

[Micawber]

Thanks - I suspect you are right. Do you think the voltage drop that I am seeing is from the worn/dirty/corroded relay contacts on the original relay. I see 3 relays in your picture. Is one of these the culprit?

 

[TheOldHokie]

Do you think the voltage drop that I am seeing is from the worn/dirty/corroded relay contacts on the original relay.

Or the safety interlocks.

Dan

 

[Mark_BX25D]

Here’s what I’m seeing now:

• If I disconnect the Black/White wire from my added relay, it reads 12V when I turn the key to “start.”
• As soon as I connect it to the relay, the voltage drops to about 4V.

Classic symptoms of resistance in the circuit, usually cause by corrosion. Find the bad connection.

Yes, the original relay could be the culprit. Anything that is in series could be the culprit.

 

[Micawber]

Thank you for the feedback. I am starting to be convinced it is a corroded relay or ground. I have checked all the safety switches. They have continuity and the voltage on them is right at 12V. As soon as it dries out a bit here in Louisville, I plan to look at the starter relay installed by Kubota. Sounds like it is behind the dashboard. I originally thought it was one of the relays near the fuse box.