G1800 start problem

[patwsharon]

I discovered this forum a few days ago and I think you guys will be able to help me with my start problem. I have a G1800 purchased in 1989 and runs great. The problem I'm having is: it will not start with the key switch. Here is everything I have done so far: checked the safety switch for the mower, seat switch, brake switch - all safety switches check out fine. I've done a continuity check on the key ignition switch itself and its fine. The battery is holding a full charge, starter and solenoid are strong. When I turn the key to the run position and jump from the positive pole on the starter to the spade on the starter solenoid, it starts right up, no problem. I also did a continuity check from the wire at the solenoid up to the ignition switch. No problem there.

The question I have is this - Are there any other safety switches other than the 3 I have mentioned? Is there anything else I should take a look at? Since all of the things I've done check out, should I assume that it is in the brain box down by the left hand side of the engine or maybe in the smaller brain box behind the screen under the dash? Is there anyway for me to check those brain boxes for any kind of failure? I know that I can bypass the key switch and just run a manual switch and the tractor will work fine, but I really would like to figure out what is wrong here and fix the problem.

If any of you guys looking at this are in Oklahoma, I live just outside of Tulsa and would appreciate any recommendations you have regarding reputable repair shops. I will specifically looking for a place that could check those computer brains if I'm not able to do so myself.

Thanks in advance for any feedback, guys. Pat W

 

[jinman]

Read this thread and see what you think.

I think your switch is getting old and has dirty contacts. You can still read continuity, but there is contact resistance that drops about 1 volt or more and is just enough to keep the solenoid from energizing. When you start to draw current through the dirty contacts, they get hot and open or have very high resistance. I'd bet if you measured the voltage applied to the solenoid you'd see it is down to 9.5 to 10 volts instead of 12 vdc. My permanent "hot wire" using a 15 amp switch from NAPA has cured all my starting problems. I cycle the glowplugs and then hit my switch and the engine starts every time. Bear in mind that you are bypassing all safety features when you do this. My seat and pedal safety switches were already defeated when I bought my G1800, so it was nothing big to just bypass the ignition switch.