starting problems on scotts 1642s

[toohott7718]

can I bypass all the safety switches to make sure that it is a bad ignition switch? Is it just a matter of put a wire from one terminal to the other on each safety switch? How about on the one safety switch that has four terminals? thank you everyone for all your help

 

[sox3]

yes you can bypass the safety switches, on the 4 wire switch you have to test to see which wires are connected when the switch is operated, use a volt ohm meter. then jumper accordingly. The best and easiest way, it to get a wiring diagram of the unit and follow the circuits with a test light. If your power drops out when you turn the key switch, (you said earlier) then jumping the safety switches probably wont help.

 

[toohott7718]

yes you can bypass the safety switches, on the 4 wire switch you have to test to see which wires are connected when the switch is operated, use a volt ohm meter. then jumper accordingly. The best and easiest way, it to get a wiring diagram of the unit and follow the circuits with a test light. If your power drops out when you turn the key switch, (you said earlier) then jumping the safety switches probably wont help.

I'm not sure I understand what you mean by "on the 4 wire switch you have to test to see which wires are connected when the switch is operated, use a volt ohm meter. then jumper accordingly"
Also if the safety switches are bypassed and it starts that means it would be a safety switch problem correct? But if it doesn't the only thing left would be the ignition.
I'm trying to understand how this system works.. when you turn the key does it make sure all safety switches are engaged then engage the solenoid then engage the starter and start the mower?

 

[hawkeye08]

Yes, you have 3 safety switches, the two mentioned above (seat and brake), the third is the mower engagement. Is the mower disengaged? The yellow handled lever by the steering wheel should be pointed to the right (3 o'clock position). IIRC, the actual switch for the blades is down on the deck perhaps?

 

[toohott7718]

Yes, you have 3 safety switches, the two mentioned above (seat and brake), the third is the mower engagement. Is the mower disengaged? The yellow handled lever by the steering wheel should be pointed to the right (3 o'clock position). IIRC, the actual switch for the blades is down on the deck perhaps?

the mower engagement isn't engaged, I even tried pressing in the yellow bypass button just to see if that would work and still nothing

 

[sox3]

OK, if you want to by pass all the stuff heres what to do. remove the 2 small wires from the solenoid.
run a new wire from one of the small terminals (either one)on the solenoid to a ground point(frame, battery etc)
fron the ignition switch find the wire that has power out when key is turned to the start position.Then run a wire from that point to the other small solenoid terminal. The unit should crank over then. All safty systems will be bypassed. I dont know if it will start as there may be a safety system killing the spark, but it should crank.

 

[toohott7718]

I just put a jumper from the +battery to the purple wire on the solenoid and it cranks over, it also cranks over when I put a jumper from the battery+ to the purple wire on starter (I assume it is the same wire). Does this rule anything out??

 

[sox3]

No, it just bypasses the Ignition switch and all the safety systems. As has been said here before, to find the problem you have to trace the flow of current through the system. A wiring diagram would be good as you can follow the path from key switch to solenoid.

 

[toohott7718]

No, it just bypasses the Ignition switch and all the safety systems. As has been said here before, to find the problem you have to trace the flow of current through the system. A wiring diagram would be good as you can follow the path from key switch to solenoid.

I noticed that there was a relay (it looks like one anyway) is there a way to test it? I looked over the wires on the mower and from what I can see all the wires look intact. Does that purple wire go directly from the solenoid to the ignition, if so I can try running a new wire to see if it is bad
Also do you know where I can find a wiring diagram?

 

[cgutenschwager]

I noticed that there was a relay (it looks like one anyway) is there a way to test it? I looked over the wires on the mower and from what I can see all the wires look intact. Does that purple wire go directly from the solenoid to the ignition, if so I can try running a new wire to see if it is bad
Also do you know where I can find a wiring diagram?

If you are handy with your multimeter, you can check the continuity... that would tell you 1) if its the same wire 2) if its broken or not.

 

[sox3]

The relay operates like a solenoid. I can test them, but I dont know if you can. Google it and see what comes up. I
would be willing to bet that the wire from the Ignition switch does not go direct to the solenoid. It probably goes thru a safety switch or two, maybe the relay also. Have to google or contact the mfg for a diagram. If you have the manual for it, check there. Need the model # off of the unit. I could research it if you would post it.

 

[sox3]

Found this on line, hope it helps



If your relay is normally closed, 30>87 should be zero. If normally open, it should be infinity.

If it is dual , 30>87A is normally closed, while 30>87 is normally open. This will reverse when the relay is energized.



Another way, is to simply put 12V power across 85 and 86. You SHOULD hear a very distinctive click as the coil pulls the internal switch over from 87A to 87. Then measure 30 to 87 (should be around 0)and 30 to 87A (should be ALOT). Power off, and the measurements should be just the opposit.


That being said, the fastest way to check a relay is to just jump the coil across a battery, and listen for the click. You can use the multimeter to check for continuity across the switch

 

[toohott7718]

Ok, I took off all the safety switches and tested all of them, they all tested out good. I looked at my test light and I thought when it lit up green it meant it was power, I was wrong. Red is positive and green is negative. I put back all the safety switches and tested voltage at the ignition. It seemed to be bad, so I replaced the ignition, and still wouldn't start.
I put my test light on the red wire at the ignition and it showed a very faint red light. I pulled on the red wire and it goes straight to the battery. So I got a scrap peace of wire and ran a new power wire to the fuse that runs to the ignition and I turned the key and it started.:cool2:
I'm not really sure how a wire that is ran through a channel with other wires went bad but I guess anything is possible.
Thank you everyone for all your hard work and suggestions, I really appreciate it.:thumbsup:

 

[sox3]

Glad you finally got it solved. I know we use to find bad wires on MTD machines where the deck lift linkage would rub through the wires and short out.

 

[toohott7718]

yeh its funny on the body of the mower there is this channel that the wires go through, no moving parts to rub against them. I guess crazier things have happened. thank you again for all your help