Scott 1642 not turning over

[remorr316]

Hi Guys,

This is my first post, so tks in advance. I am a retired medical person -- so equipment repair is not an everyday endeavor. But since I have more time -- I decided to learn how to repair what I paid someone else to do for me before retirement.

I am working on a old Scott 1642 -- its about 12 yrs old and I was going to take to scrap yard and decided to see if I could get to work again. When it died several yrs ago -- It failed start after I had turned it off. At the time I felt it was ignition key problem and since was old I just bought a new mower and parked the old one.

I started off by changing the ignition key, new oil, new spark plug and fogged the cylinder, cleaned gas tank and attempted to clean the carburetor. It had a solenoid on the bowl and this turned out to be bad and the inside was more corroded than I thought should be and it kept filling with gas -- so I replaced the whole carburetor. It still would not turn over so I hot wired across the solenoid and was able to to get started. I attempted to figure out a way to take out the old solenoid -- it is locate just in front and behind the right rear wheel. I really don't know how to get this out short of cutting the two screws with a hacksaw --- even that way it would be very difficult -- it is a very tight space. Has anyone had this problem before and how was it solved? Tks

 

[SeniorCitizen]

I wouldn't be too hasty in replacing the solenoid because it depends on how/what you hot wired that made it crank.

It may not need replacing at all and you become a parts changer like the ignition switch was replaced to no avail.

It could be that the solenoid is not getting electric power to energize the internal contacts because of a malfunctioning safety switch.

 

[remorr316]

I wouldn't be too hasty in replacing the solenoid because it depends on how/what you hot wired that made it crank.

It may not need replacing at all and you become a parts changer like the ignition switch was replaced to no avail.

It could be that the solenoid is not getting electric power to energize the internal contacts because of a malfunctioning safety switch.

>>>> Thanks for the reply ---- OK, point well taken --- research on-line reveals four safety switches on a Scott 1642
1) Brake - inside the frame, next to the brake pedal
2) DECK/PTO - underneath the fuel tank, at the base of the dash assembly
3) SEAT - underneath seat
4) REVERSE - on top of the transmission

The way I hot wired it was with a wrench across the two solenoid terminal -- it turned over doing that --- it is a four pole solenoid and a test light across the ignition terminals (with the key on does not show power.

How can I determine which are defective and which are not? How can I determine it is not the solenoid -- the battery is new and charged -- Test light shows there is power to first solenoid terminal ----- The brake SS has four wires from it -- two green and two white with dashes ---- I am unsure how this four wire switch works -- I would think the two greens are hot and a test light should light --- but it does not --

The seat SS has two wires one green and one white with dashes ---

I am thinking the green is the hot wire and the white is the ground --- If I disconnect these two -- it should result in a open circuit -- (sit on the seat pushes the button down and opens the circuit) but there is no power to the green wire. (or the white) --

There is a fuse somewhere that I have not located and there are two other SS -- they are more difficult to locate and I have not gotten there yet.

Any guidance is appreciated Thanks again

 

[mechanic mark]

Try rotating top of engine by hand, you may need to remove spark plug first. I know you have an electrical issue, but this will let you know if engine is not locked up. A fuse is usually located between ignition switch & solenoid. An in line diode, located in main wire harness, is possible culprit for not turning over. Seat safety switch is possibility & where I would start by seeing if you have power to switch. As you mentioned above no power to seat switch wires with key on, back trace wires to see if they are pinched etc. Check all ground wires also to chassis.

http://www.greenpartstore.com/S1642_c_202-2-3.html

 

[SeniorCitizen]

>>>> Thanks for the reply ---- OK, point well taken --- research on-line reveals four safety switches on a Scott 1642
1) Brake - inside the frame, next to the brake pedal
2) DECK/PTO - underneath the fuel tank, at the base of the dash assembly
3) SEAT - underneath seat
4) REVERSE - on top of the transmission

The way I hot wired it was with a wrench across the two solenoid terminal -- it turned over doing that --- it is a four pole solenoid and a test light across the ignition terminals (with the key on does not show power.

How can I determine which are defective and which are not? How can I determine it is not the solenoid -- the battery is new and charged -- Test light shows there is power to first solenoid terminal ----- The brake SS has four wires from it -- two green and two white with dashes ---- I am unsure how this four wire switch works -- I would think the two greens are hot and a test light should light --- but it does not --

The seat SS has two wires one green and one white with dashes ---

I am thinking the green is the hot wire and the white is the ground --- If I disconnect these two -- it should result in a open circuit -- (sit on the seat pushes the button down and opens the circuit) but there is no power to the green wire. (or the white) --

There is a fuse somewhere that I have not located and there are two other SS -- they are more difficult to locate and I have not gotten there yet.

Any guidance is appreciated Thanks again

Good point about load testing the battery and that's what I often do first, but it starts by jumping across the two large copper terminals on the starter solenoid so the battery is doing its job.

Jumping those two terminals is the same as putting a jumper cable from the + battery terminal to the + terminal on the starter. That doesn't tell us if the electromagnet inside the solenoid is closing the internal contact points that is supposed to complete the circuit. That electromagnet has to be energized by the small wires through all of the cranking circuit key switch and safety switches.

There won't be power to the two small terminals on the solenoid unless the key switch is in start position.

The PTO switch is a dual function switch. PTO off allows cranking circuit to be completed. PTO on allows safety switch circuit to be completed.


A wiring schematic would be most beneficial. If I've made any mistakes attempting to help this poster corrections and or additions are welcome.

Pictured is a dual switch from an old Murray I have. 2 switches inside but never make connection simultaneously.

 

[remorr316]

Try rotating top of engine by hand, you may need to remove spark plug first. I know you have an electrical issue, but this will let you know if engine is not locked up. A fuse is usually located between ignition switch & solenoid. An in line diode, located in main wire harness, is possible culprit for not turning over. Seat safety switch is possibility & where I would start by seeing if you have power to switch. As you mentioned above no power to seat switch wires with key on, back trace wires to see if they are pinched etc. Check all ground wires also to chassis.

http://www.greenpartstore.com/S1642_c_202-2-3.html

Thanks for the reply ---- engine is not locked up -- turns with ease --- There is no power to to the seat switch -- I tested this by test light grounded to frame --- I will verify that the battery ground to frame is not a problem and do some back tracking on ground this PM --- I don't have a muliti-meter --- and will have to get one ----
I have retired and live in a log cabin on the edge of a wildlife management area --- It is about a 45 min drive to larger stores that carry parts and tools. My test light is a 12v bulb soldered to two wires. Not fancy but it works.
Again thanks for the info

 

[remorr316]

Good point about load testing the battery and that's what I often do first, but it starts by jumping across the two large copper terminals on the starter solenoid so the battery is doing its job.

Jumping those two terminals is the same as putting a jumper cable from the + battery terminal to the + terminal on the starter. That doesn't tell us if the electromagnet inside the solenoid is closing the internal contact points that is supposed to complete the circuit. That electromagnet has to be energized by the small wires through all of the cranking circuit key switch and safety switches.

There won't be power to the two small terminals on the solenoid unless the key switch is in start position.

The PTO switch is a dual function switch. PTO off allows cranking circuit to be completed. PTO on allows safety switch circuit to be completed.


A wiring schematic would be most beneficial. If I've made any mistakes attempting to help this poster corrections and or additions are welcome.

Pictured is a dual switch from an old Murray I have. 2 switches inside but never make connection simultaneously.

Thanks for the reply -- I verified that the ignition is in the on position -- test shows no power to the two small terminal --- it could be the fuse I search it out ---- and get back with you

 

[SeniorCitizen]

There won't be power to the two small terminals on the solenoid unless the key switch is in start position.

We wouldn't want power to the starter solenoid while mowing in the run position.

 

[mjb8fj]

Thanks for the reply -- I verified that the ignition is in the on position -- test shows no power to the two small terminal --- it could be the fuse I search it out ---- and get back with you

the starter solenoids are all kind of the same thing, three post or four- dosent matter. I get this question a lot and here's a simple way to look at it, there are two large wires, one comes from the battery and the other goes to the starter. The 3 terminal post- one coming from the battery, one to the starter, the smaller wire is hot- when the key is turned to the START position. The solenoid has to have a good ground to the frame.
4 post or terminal, same two big wires, battery and starter, one terminal will be hot or positive when in START, the other wire is a ground. Dosent matter which wire is hot or ground.
These are all the same, cars, boats, atv's..... all they are is a magnet that closes or opens (depending how you look at it), and passes the power from the battery to the starter. When the key is released, it shuts that hot or small positive wire off, the magnet opens, stopping the power to the starter.
If yours is older machine, its possible that yes the starter solenoid is bad, not completely closing and not sending all the power to the starter, or that the ground on it is not getting a good ground. I have had many where the big battery cables, one has 12.6 (full battery power), and when starting, the magnet closed and sending 8 volts to the starter, the starter either slowly spins or dosent at all on some.
Either way, most of the time these are about $8-$12 depending where you get them. Don't let some kid behind the counter try and tell you that you need a specific one for your machine, or the dealership says the same thing.

 

[remorr316]

Thanks again for the reply and info ---- I finally got tired of trying to work and explore under a mower so low and just turned it over so I can see underneath.. I was able to find the fuse and and the 2 other SS -- The fuse was blown and I went to Tractor Supply --- I got some fuses a multi meter and a universal solenoid -- Inflation is here guys --- solenoids cost 20 bucks. I will take it back if it turns out I don't need it.

I did not have gas in the tank but some oil did drain but I will deal with that later.