Scag 61" 31EFI Won't Start

[Farmer Mike]

Last fall this mower would (sometimes) start after repeatedly turning the key to the start position. You can always hear the fuel pump run and the volt gauge would always go to the far left at -8. I replaced the ignition switch with a brand new one thinking this was the problem. No, that was not the problem. Place key in switch and volt meter needle is straight up and down. Turn key to on position fuel pump runs and then turn to start and volt meter instantly goes to far left again no cranking, starter don't even click. No amount of times turning the key will start it now. Seems like there is a dead short somewhere. This mower is out of warranty now but it only has 116 hours on it. First day when I got it the volt gauge was defective and my dealer replaced it. Took it home and was back to dealer again within first week because of a bad oil leak on top of engine. I love the mower and it does a great job but it needs to be more dependable. Does anyone have an ideal on what I need to get her going again ?

Battery is fully charged. I've checked all battery and cable connections to frame and starter. Found one fuse and it looks to be good. All of the safety switches are in the proper positions for starting. Mower has never been rained on or wet. I'm at a loss.

Thank You, Farmer Mike

 

[Rivets]

Here is a procedure which two of us developed for lawn tractors. With a little tweaking you should be able to use it on your unit. Let us know if it helps at all.



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.

 

[Farmer Mike]

Hi Rivets, Thanks for the reply.

I will round up the meters and give it a go.

I did find three more fuses and they looked great too. I'll let you know soon as I get the meters in hand.

Thanks, Mike