1641 blows the 20 amp fuse
 

Hello Again Gang,

Was happily mowing along when I was called in for lunch. Parked the 1641 went in and ate, came back out and turning the ignition key blows the 20 amp fuse next to the solenoid. Even though the PTO switch was in the off position, I unplugged the PTO, and it still blew the fuse upon turning the key. Any suggestions would be greatly appreciated.

Thanx Bob

Well, It's not the PTO circuit.

I could be a number of things to include the Ignition Switch itself. Looks like it is time to dig out the DVM and start looking for "shorts".

Thanx Roland. Just wondered about that. The fuse blows as soon as you turn the key. This tractor was bought new by my step father in the early 90's. It's not been molested wiring wise (I did jump the microswitch to shut off the pto when in reverse) and most stuff is still original. Is there any where to get a schematic for the wiring?

Sure sounds like a Ignition Switch to me. I'll look up the diagram tonight & forward it to you.

I was gonna go ahead and order a new ignition switch anyway. Who could even fathom the amount of times it was turned in 28 years and 1050 hours of operation? Thanx for taking the time to look for the diagram.

I appreciate the help... Bob

Play Sherlok
 

It's easy to take the ign. sw. out and test the individual connectors. It might also be the starter has locked up or has a short in it. You can go to the solenoid and jump it and see if it is the starter. If it starts then it may be your switch. Good luck

Diagram sent to the E-Mail address listed in your profile.

I did a Crapsman yesterday with the same problem. The wire that engages the solenoid was chafed and touching the frame. Took me a bit to find it cause of all the dirt and such. At least you know it in the starting circuit.

In the service books and schools they always preach to isolate the systems when doing elec work. I did a 26 command on a Toro with fuel injection the other day had no spark. We don't do enough fuel injection, or ECM's, to have the soft ware package so we went threw and isolated the different circuits. Never threw a fault code but by taking the different systems out of the harness we narrowed it down to the speed sensor. Then from there we found a connector in the harness for it was pushed out of the back not making a connection, and not letting the coils fire.

Yes its true, Ill admit it you disable the safety system, but this is how it tells you to do it in the shop repair manuals. Also I'm sure, cause Ive seen it done, on the scanners for your car to trouble shoot you do the same thing. Isolate the systems, weather you put the ECM into limp mode, no start or take the fuel rail out of the equation to test for compression threw an amp gauge. When I worked for cat they would run our ECM's via remote controlling the throttle via lap top with no one in the truck.

Could it be something in the light circuit? That is the first position that the switch energizes.

Todd could be. Like what was mentioned shorted switch internally. This is why you isolate the differant circuts.

Thanx for all the input guys. It's not the ignition switch unless the new one is bad out of the bag, lol. Thanx for sending me the wiring schemetic, Roland. Out comes the meter to begin checking stuff. I'll keep younz posted. Thanx again everyone.

Kudos to Mr. Oak! It appears to be the light circut. I pushed a small screw driver into the plug for the ignition switch to remove the blue wire from the plug, plugged the switch back in and with my last 20 amp fuse, turned the key. Engine turned over and didn't blow the fuse. I'm gonna tape off the blue wire and finish mowing for now and search for the short when my grass is a little more managable. Trying to remember the last time i mowed at nite. Lol.

I really appreciate all the help guys. A knowledgable sounding board is a wonderful thing.

Thanx again,
Bob