Electrical - Turning switch drops voltage to starter solenoid, no start

drunderw · Jun 6, 2018

Good morning -

I hope everyone has been doing well and enjoying some warmer weather.

I am having a conundrum regarding my YM3110d starting.

As of yesterday, when I turn the key to accessory I get no lights on the dash. I put a voltmeter on the positive post on the starter solenoid and BEFORE I turn the key I have 12v read and when I turn the key the voltage drops to 0.

I was able the day prior to connect jumper cables from my truck to the tractor battery and got lights when turning the key to accessory and then the tractor would attempt to start but turned over very slowly like it had a dead battery. Because of this I took the battery back out and to Interstate for testing and they re-verified it was good (since it was new, but I wanted to check). On two occasions as well when I've turned the key to start I've heard a pop but have been unable to identify any point of issue with the wiring. I did have issues leading up to this where I had to jump start the tractor each time but I'd gotten a red GEN light and the previous battery was 3 years old and was in the tractor when I purchased it so I assumed it was just the battery going bad.

Some things I have done:

New battery, load tested by Interstate Batteries
New terminals on + and - cables
Verified negative is connected solid to the frame
Verified voltage at the battery
Verified voltage at the starter solenoid
Replaced starter solenoid with a new from Hoye

I'm going to pull the kickplate on the dash to get at the wiring under the dash to see if anything weird in there. Any other thoughts of things for me to try? I have a big need to get my field cut before next Monday and am running out of time since I unfortunately can only work on it after work in the evening for a bit at a time.

Thanks so much!

David

winston1 · Jun 6, 2018

"Verified negative is connected solid to the frame" Did you take it off and clean, then reinstall? If not, might try it. That point is guilty many times.

The pop you are hearing could be a bad connection or cable. They will sometimes spark out at bad points.

drunderw · Jun 6, 2018

I did not remove it, just checked to see if it was loose. I'll try that as well this evening. Thanks

normde2001 · Jun 6, 2018

How many volts are in battery, (EXACTLY)?

drunderw · Jun 6, 2018

I don't remember the exact number right now, I can get it later when back at home, but something like 12.37v comes to mind - it was 12.something.

normde2001 · Jun 6, 2018

You need 12.6V minimum for starting. Chrge to 13.1-2v before testing. That is not a 12v battery it is a 12.6v battery

aczlan · Jun 6, 2018

Put multimeter on the positive terminal, then on the battery lead of the starter solenoid and try to start it. Repeat from the positive terminal to the "switched" side of the starter solenoid and from the negative terminal to a bare metal part of the starter housing.
Any reading of more than 1 volt means that there is a problem with the cable or its connection points.

Aaron Z

drunderw · Jun 6, 2018

Ok- I disconnected the ground (bolt connecting cable below the radiator) and sanded where it connected to the frame and both ends of the cable removing the battery terminal (new) to sand where the cable connects.

After doing that I still get no dash lights when turning on the switch.

Here are my voltmeter readings. To Aaron痴 post I do get readings greater than 1 where I shouldn稚 with the switch turned to accessory or start.

At the battery posts, 12.85

Solenoid with negative to frame, result is 11.20v

Press solenoid in to engage, reading on solenoid with + to solenoid - to frame bolt goes to 0v

Put multimeter on the positive terminal, then on the battery lead of the starter solenoid and try to start it, result is 12.87v only when I turn the switch to accessory or to start

Repeat from the positive terminal to the "switched" side of the starter solenoid, Same result as above

and from the negative terminal to a bare metal part of the starter housing, result is 0v

Bad switch? I don稚 see any issues with the positive wire, I知 perplexed.

Thanks

rScotty · Jun 7, 2018

Sounds to me like a bad battery. I know you said it was load tested, but the things you mention happening are common when a battery goes bad in a particular way so that it has voltage but not much available amerage capacity. "ampacity".

Here's a simple test for ampacity. Take a car headlight bulb and connect it directly across the battery terminals. You can leave the battery in the tractor and hooked up but without the key being turned on. Now does that headlight light up and stay bright for 5 or 10 minutes? If not, the battery is at fault. Simple as that.

The other common possibility is that there is a dead short to frame ground in the starter or the solenoid. And it would have to be such a low resistance short that all the voltage flows directly to the frame ground, leaving no voltage for the meter to read. If that happens I'd expect that cable between the battery + terminal and starter solenoid to get real hot. Also the cable between the - terminal and frame ground would get hot.
That's the test for a dead short in the starter or solenoid that the battery cables get really hot.

One thing else really bothers me, and if the battery is OK it might just give us the answer. What bothers me is where you say that the voltage across the battery posts is 12.85 volts but the voltage from the solenoid to frame is 11.2 volts. Normally, that just can't happen. It's so weird that at first I dismissed it because those voltage just cannot be different. The battery and the solenoid hot terminal are connected by one short wire which goes nowhere else. They have to have the same voltage - always.

Then I got to thinking..... The only way they could be different is if the motor block was not grounded to the frame of the tractor. I guess that is possible though odd.. Just for grins, why don't you run another ground wire from the negative post of the battery to the case of the starter itself. Better make it a thick wire. In fact, make it is thick as a battery cable or use a battery cable if you have a spare. And wear safety glasses when you try to start it.
luck,
rScotty

rScotty