no start, starter motor drops 12v

[moblakely]

This might make everyone else as insane as it has me. Working on my.moms mower... no idea when last running.. sometime last season I believe. It wouldn't fire so I looked at all the typical stuff. I have a kohler cv165 which there is no manual available for on website. I have hydraulic valves so no adjustment needed there. I jumped at starter too much and burnt the wires in it. Replaced starter. Couldn't get 12v to starter so I checked wiring at starter solenoid. I was getting 12v on positive in post but not on the post out to starter. Checked more and the white wire from blade disengage safety connector didn't have 12v. Replaced that white wire and grounded solenoid. Finally got 12v to other solenoid post. Checked voltage at starter before attaching to body it had 12v with clutch in and key turned.... now here's the weird part. Touched starter to body and lose the voltage. Ideas?

 

[reynoldston]

poor connections.

 

[moblakely]

OK. I get 12.5 at ignition, clutch and blade safety. The ground on solenoid gets 12.5 til I ground it. The white wire on solennoid gets 12.5. Should I be looking for 12.5 on the seat safety too? Jumping solenoid terminals does nothing as well as going straight the the starter. I'm lost but when I get it I will post results to help others.

 

[Rivets]

Try this troubleshooting procedure. Can you post all the engine and unit numbers so we know what you are working on?



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 (you may need an assistant to sit in the seat to override the safety switch). *If you have power what is the voltage?

Fifth, check for power at the starter while holding the key in the start position (assistant again). *If you have power what is the voltage?

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.

 

[moblakely]

1. I understand mechanical much better than electrical, but I'm learning.
2. I have a multimeter I'm pretty comfortable with
3. I can follow directions
4. I never assume anything

Fuse is good, battery terminals clean with over 12.5v

I get over 12.5 to the first (positive in) terminal on solenoid.

Solenoid is tightly mounted and I get over 12.5 on white wire with clutch depressed and key to start.

With key+clutch I also get over 12.5 on other solenoid terminal (when starter is unattached), this voltage disappears when starter is on mower.

I have no voltage on starter when attached to mower, but do have it when it is not touching anything.


Now, I started on it again this morning and since I've checked all the hot wires I started looking at all the grounds. This is my amateur hour question.... when I turn the key/press clutch, the ground under the chassis (from the battery) gets a little over 11v.... so, is that correct? I'm confused (or doubting myself rather) about ground wires. should they have a charge at all when circuit is complete? When not trying to crank there is like 0.03-0.04v on that ground at rest. any quick explanation of ground voltage would be helpful. Thank you.

 

[moblakely]

all right with some more googling I realize that voltage on the ground at chassis under seat probably doesn't tell me anything. I ohmed out all the black wire on the ignition circuit (or what I believe is the ign circuit and got no more than 0.03 ohms everywhere between them and the neg terminal on battery. I don't know if that should still be true on the grounds on other side of ignition circuit as I got 41.6 ohms between solenoid body ground on the chassis and neg terminal, 44.5 on the kill wire at the ignition module and about the same reading on the grounds around the carb (fuel solenoid). though being those were all in the same range, they must be a seperate circuit and I should have the neg lead on a different ground other than the negative battery terminal when checking those... not sure where. When I try to crank I'm losing over 1v in the battery.

Only thing I haven't checked is the transmission switch, shouldn't there be one? and if so where may I find it? I tried to follow with my hands around under the mower past the trans lever. I've identified all the others.

lastly I popped off the kill wire and gave it a try with no difference

I also feel like it's worth mentioning that the very first thing that was done to this mower months ago was replacing the ground (-) wire off the battery to the chassis because it was the first thing I saw messed up. It was fried. Since I have replaced battery, starter solenoid and starter.

 

[Rivets]

If you have 12V on the solenoid output terminal (which goes to the starter) when you turn the key to the start position, this means one of three things. One, you have a poor ground between the starter and the engine. Two, you have a bad battery. Three, you have a bad starter. Let's check the battery a different way. With the starter mounted on the engine and the volt meter attach accross the battery terminals, what is you battery voltage when you turn the key to the start position. It should drop, but no lower than to 10.5V. If it drops below 10.5V and it was fully charged, I would say you have lost a cell in the battery. If the battery tests good, then we will test the starter a different way. You will need a set of jumper cables. Remove the starter from the engine and using the jumper cables hook negative to battery and clamp the other end on the starter body. Attach one positive end to the battery and touch the other end to the starter terminal. If it spins the starter is good. Let me know what happens.

 

[moblakely]

Battery did not drop below 10.5v and starter bench tested fine. Thanks for your help... I guess I will go to cleaning the mounting points of the starter and give that a try.

 

[Fish]

First, check and make sure that the battery is hooked up correctly.

Second, listen to Rivet's suggestions and get back with the results, put the multi-meter away for now, you have
something basic that is wrong.

Also listen to him and post your engine's and tractor's model/spec. numbers.

And if you can, snap some pics of your battery, solenoid, etc....

 

[ben.cellamare]

Try this troubleshooting procedure. Can you post all the engine and unit numbers so we know what you are working on?



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 (you may need an assistant to sit in the seat to override the safety switch). *If you have power what is the voltage?

Fifth, check for power at the starter while holding the key in the start position (assistant again). *If you have power what is the voltage?

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.

I am having similar issues but on the fourth checkpoint I am only getting 6 volts at the second terminal going to started and starter only has the same amount of volts. Where am I losing the voltage from? I have taken and cleaned all of the ground wires. Thanks for your help. This has been frustrating