YT4000 Start Issue

Covy

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Tractor: YT4000
New Battery: Reads 12.1 VDC

Solenoid/Starter
When turning the key, nothing happens. No clicking of the solenoid even. When checking the power to the solenoid, there is power.
  • Start Switch: Testing the start switch shows that turning to the start position properly connects power. (disconnected switch, checked continuity between the S & B pins when switch is turned to start)
  • Solenoid: Using a screwdriver across the screwdriver to power the starter directly (I know, bypasses safety switches), still nothing.

Lights
Also - the lights do not turn on either, which I find odd. I tried turning them on with the key on, in start position, still nothing. Most of the electrical drawings show it coming right off the key (inaccurate), but just found one that looks like the power comes through the switch and then alternator - which then makes some sense as to why the lights do not turn on.

I used the following electrical diagram which should be the correct electricals: https://tractorfile.com/wp-content/...o-yt-4500-craftsman-tractor-parts-diagram.jpg

So at this point I would think it is the starter that is the problem.... But I still would expect to hear the solenoid click, which it isn't. So - I am confused.
 

StarTech

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Might be a bad ground return. Things like loose ground mounting screws or corroded cable end, or bad cable.

As for the lights they don't receive power unless the engine is running according to the wiring schematic posted.
 

Covy

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I checked to see if there were a ground problem doing the following:

  • Checked across #1 (battery positive) and #2 (battery negative): 11.4VDC
  • Checked across #1 (battery positive) and frame: 11.4VDC (if I made sure the connection was good)
  • Pulled the solenoid wires off and checked #1 (battery positive) and #3 (black coil wire post): 11.4VDC
  • Jumpered #3 (black coil wire) to ground on motor, Jumpered #4 (power to solenoid) to #5 (white coil wire post) - This should have gotten the starter going. Nothing.

To me, that says I should be able to use the screwdriver trick on the solenoid to jumpstart the starter (provided 11.4 VDC is enough to get it going). So - is it the starter? Or do I need to run some other tests?YT4000-Testing.png
 

Rivets

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Here is a procedure which I recommend to find the cause of starting problems. With the results we will be able to tell you how to proceed.

Electrical* problems can be very easy or very difficult, depending on four things.
1. * How well you understand basic electricity.
2. *What tools you have and know how to use.
3. *How well you follow directions.
4. *You don't overlook or assume anything and verify everything.

Remember we cannot see what you are doing. *You are our eyes, ears and fingers in solving this problem. *You must be as accurate as you can when you report back. *The two basic tools we will ask you to use are a test light and a multi-meter. *If you have an assistant when going through these tests it would be very helpful. *These steps work the best when done in order, so please don't jump around. *Now let's solve this problem.

First, check the fuse(s), check battery connections for corrosion (clean if necessary) and *voltage - above 12.5 volts should be good.*

Second, check for power from the battery to one of the large terminals on the solenoid. *One of the wires is connected directly to the battery and has power all the time so one of the large terminals should light a test light or show 12 volts on a meter at all times.*

Third, *check for power at the small terminal of the solenoid while depressing the clutch/brake pedal and holding the key in the start position (you may need an assistant to sit in the seat to override the safety switch). If your solenoid is a four wire solenoid, check both small wire terminals as one is ground and the other is power from the ignition switch. *If your solenoid is a three wire solenoid, make sure the solenoid body is not corroded where it bolts to the chassis of the mower as this is your ground path back to the battery. *If in doubt, remove the solenoid and clean the mounting area down to bare metal. *If there is no power to the small terminal then your problem is most likely a safety switch, ignition switch or in the wiring.*

Fourth, check for power on the other large terminal of the solenoid while holding the key in the start position q(you may need an assistant to sit in the seat to override the safety switch).*

Fifth, check for power at the starter while holding the key in the start position (assistant again).*

Sixth, check your ground circuit back to the battery.

After you have gone through each of the above steps, let us know what happened when you did each step. *At that point we will have great info to tell you how to proceed. *Remember you are our eyes, ears, and fingers, so please be as accurate as possible.

Be as specific as possible with voltage readings as this will help diagnose your problem quicker. *If you do not know how to perform the above checks, just ask and I will try to guide you through it. *Youtube also has some videos and as you know a picture is worth a thousand words.
 

Covy

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First, check the fuse(s), check battery connections for corrosion (clean if necessary) and *voltage - above 12.5 volts should be good.*
This was trickier than I thought. At first it showed 11.5V. Then 11.7V. What I noticed in subsequent steps was that when I was on the mower, the voltage could change all the way to to 12.7 depending upon where I was standing. Steady-state was 11.7V, though.
**EDIT** No corrosion at all on the battery posts or connections, the only fuse (20 Amp) was intact and tested same with Ohm reading.

Second, check for power from the battery to one of the large terminals on the solenoid. *One of the wires is connected directly to the battery and has power all the time so one of the large terminals should light a test light or show 12 volts on a meter at all times.*
11.7 V
Note: When removing the ground wire from the battery post and testing against the positive battery post and netgative post (with negative post cable removed), the voltage jumped up to 12.6V.


Third, *check for power at the small terminal of the solenoid while depressing the clutch/brake pedal and holding the key in the start position (you may need an assistant to sit in the seat to override the safety switch). If your solenoid is a four wire solenoid, check both small wire terminals as one is ground and the other is power from the ignition switch. *If your solenoid is a three wire solenoid, make sure the solenoid body is not corroded where it bolts to the chassis of the mower as this is your ground path back to the battery. *If in doubt, remove the solenoid and clean the mounting area down to bare metal. *If there is no power to the small terminal then your problem is most likely a safety switch, ignition switch or in the wiring.*
11.7 V when clutch and start were engaged

Fourth, check for power on the other large terminal of the solenoid while holding the key in the start position q(you may need an assistant to sit in the seat to override the safety switch).*
0 V

Fifth, check for power at the starter while holding the key in the start position (assistant again).*
0 V

Sixth, check your ground circuit back to the battery.
Was not an open loop


I have enough tools and a very nice multimeter, so the job was pretty easy really. Seems like a large voltage drop when the ground cable is connected, which leads me to believe there is a resistance problem (maybe corroded wire or poor connection). Moving around on the mower and seeing voltage changes makes me think it is either a broken wire or a bad wire connection/termination.
 
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Rivets

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Looks to me like you have a bad starter solenoid. I’m assuming you have a three terminal solenoid and if you have power at the small terminal and it is not closing, that indicates that the solenoid is bad. I’m also assuming you removed this solenoid and made sure that the solenoid base and the area on the chassis is clean and bare, as this surface is your ground connection.
 

Covy

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Looks to me like you have a bad starter solenoid. I’m assuming you have a three terminal solenoid and if you have power at the small terminal and it is not closing, that indicates that the solenoid is bad. I’m also assuming you removed this solenoid and made sure that the solenoid base and the area on the chassis is clean and bare, as this surface is your ground connection.

It is a 4-Terminal solenoid, actually. I ran a couple of tests on it including what you mentioned above. After that I jumpered it according to a youTube video (
). I tested power at the starter also, expecting at least the 11.7 V, but nothing there. Since it is a 4 terminal, the ground is on the small coil connection from what I saw in the electricals.
 

Rivets

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One more test. With a 4 terminal solenoid remove the small wire from the small ground terminal on the solenoid and if possible run a ground wire from this terminal to battery negative terminal. If you can’t do this, run this jumper to a good chassis ground. Now repeat the third and fourth tests I posted. If you still have 0 voltage at the large solenoid terminal going to the starter, bod solenoid. I know I shouldn’t do this, but I’m assuming you have also tested the starter by running a heavy wire jumper from battery + terminal to starter terminal and this will turn the engine over?? Am I right??
 

slomo

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Does that solenoid need a good mounting ground to clean metal? If so wire wheel time.

slomo
 
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