Wow, so many post here that offer good info! Thanks. But UPDATE: I installed a new solenoid as well (after replacing the cable with new copper!). And mower still does not even turn over. I got a 12V test light and got a light on the IN of the solenoid, an OUT of the solenoid (with switch ON), and even a light at the starter. If I get a test light on all these points, doesnt that mean I have a problem with the starter?
Corroded ring terminal, battery cable
- Thread starter rigoletto
- Start date
Check your battery voltage at the starter while engaging the starter. the voltage should stay in the 10 volt range at the lowest. If not you need a battery. Or do some load testing on the "new" solenoid. My daughter's mower was down most of the summer because of a bad new solenoid. If it all checks out it might be the starter. Be aware with a volt meter or test light. You can have 12 volts on a terrible connection until you put a load on it.
Hammermechanicman
Lawn Addict
- Joined
- Jan 10, 2020
- Threads
- 65
- Messages
- 3,826
First clean both ends of the negative ground cable.
When you turn the key to start do you get 12v from the solenoid trigger wire and ground?
If no troubleshoot the start safety circuit.
If yes does solenoid engage? (Hear it clicking)
If solenoid engaging do you 12v to ground on both large terminals of solenoid?
For probably close to a hundred years farmers have used plain old grease on battery terminal connections to stop corrosion.
- Joined
- Feb 19, 2020
- Threads
- 91
- Messages
- 11,467
Just because the test light lights doesn't mean you are getting the full voltage at the starter. Most starters in the 12v range need at least 9v to even try to turn. The OP needs to be using a volt meter for testing.
To the OP, use this procedure to pinpoint which component or wire is creating your problem.
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. Check and make sure the chassis ground is clean and tight.
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 (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.
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. Check and make sure the chassis ground is clean and tight.
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 (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.
So, if a test light that lights for 12v light up it does not mean you are getting 12V? Why do they call it a 12V test light? If I get a helper to turn the engine over and I test for V with meter I need at least 9V? I didnt know. That seems too low, no? A starter will turn over with just 9V?
Last edited:
OK, wil do. Will need a helper for that. But if this helps- battery V with no load is 12.14.
Thanks, Rivets. If I have just 12.14V on battery I have a bad battery? If I need 12.4, I understand, I probably have a weak battery. For starters! Should I even bother with all the other testing?
Across the 2 terminals of the solenoid it reads around 3.5-4.0. Fluctuates. And on far side of solenoid (terminal on right side) to the spade connector with ignition on , 2.0V or so. At starter, key on, 4-5V or so. Something is messed up.