My Tractor Forum banner

Craftsman 917-27106??

5100 Views 32 Replies 4 Participants Last post by  Bill Kapaun
I have a 90's craftsman lawn tractor with a 15.5 Kohler ohv motor. Has been running fine until a few moments ago. Now it blows the 20amp blade fuse after running for a few minutes. Any thoughts on where i should be looking. If there was some sort of short, wouldn't the fuse blow immediately? Thanks for the help.:
21 - 33 of 33 Posts
For the test light checks, leave the engine OFF.
Just the key ON.
You can have the key OFF while you swap OPR's around.
Look for one or more that lights up noticeably brighter than the others.
All 3 installed should be brightest.
Removing any one should reduce brightness.
Removing any two should reduce brightness more.
All 3 should reduce brightness the most.
The fuel solenoid should draw a similar amount of current.
With the fuel solenoid and all 3 OPR's disconnected, the light should be out, since no current should be flowing.
Remember, you have to "manipulate" the seat switch (occupied) to "turn them ON".
Look at the schematic.
Current flows from A1 on the key switch, through the seat switch to the OPR's.
See less See more
Bill, i will have to wait until tomorrow to check this, it is just too hot to work outside today.10 am and the heat index is already over a 100. By the way where in "Orygun" to you live? My daughter is home ported in Newport OR on a NOAA survey ship.
I'm 60 miles East in Albany.

Forgot on the diode-
The circuit has to be disconnected so that you are only testing the diode.
IF you disconnect OPR 2 & 3, you can insert the test leads into pin 30's of the OPR PLUGS.

Currently 54 in Newport
Ok, i tested the diode allows current in one direction and not the other. I put a shunt in the seat switch. Then put the leads from my multi meter in place of the 30 amp fuse, this is what happens: Fuel solenoid disconnected and all three OPRS removed, turn the key to on and no current flows. Plug in the solenoid, and the meter reads 10v with no OPRS. Disconnect fuel solenoid and plug in one OPR meter reads 10v replace with another OPR again 10v as well with the last OPR. Plug in OPRS one at a time in sequence, and no difference in meter reading.
Your meter should have an AMPS range.
That would be a better test.
Use the highest range you have, assuming it's at least 2 amps.
Repeat the test, adding one load at a time. (be ready to disconnect quickly if you go over range!!!!)

My gut feeling is that the relays are OK.
More likely, you have a wire where the insulation has rubbed off and intermittently is shorting. (pretty much anything that connects to A1 of the key switch)

Another possibility is a defective key switch that is shorting internally.
Not really a positive test, but you could remove the switch-
Hook OHM meter to A1 & G terminals.
In the ON position, wiggle the key, tap the body etc. and see if you show "flashes" of continuity. IF you do, that's a short.
Just got back from town will run checks as you suggest. I did replace the ignition switch this spring. Thanks again for your help.
Well, back at working on this thing. Pulled ign switch checked continutiy across A1 and G needle on meter pegs all the way over, on start and lights position, nothing. Is this switch bad?
"Hook OHM meter to A1 & G terminals.
In the ON position, wiggle the key, tap the body etc. and see if you show "flashes" of continuity. IF you do, that's a short"

It will show continuity in the OFF position.
Any other position, it should be open.

Look at the little chart (truth table) on the lower left of the schematic.
It should only do what the chart shows.
Well it looks like the switch is ok. What puzzles me is that the engine will run for a few minutes before the fuse blows. Wouldn't a dead short blow the fuse immediately? Could the starter or solenoid have some internal short? I did replace the solenoid when i replaced the ign switch this spring.
If the starter or solenoid had an internal short, it'd only blow the fuse when they were in use. (when starting)

Look for a bare spot in a "hot" wire.
It would likely be in a spot that was vibrating against metal and wore through the insulation.
You could try running it with the OPR's removed to see if it's in one of those 3 circuits.
When OPR 3 is removed, you won't have battery charging.
OPR 2 activates the flywheel brake. (I would consider it the most suspect)
Pulled all of the OPRS this morning. Put in a 30 Amp fuse, motor started and fuse blew after about 30 seconds. Could there be something in the solenoid or starter?
I answered that question in post #30.

Since were going to go into hit or miss mode-------
With all the OPR's removed-
Disconnect carb solenoid wire.
Turn key on and wait. See if fuse blows.
If not, hook up carb solenoid and repeat.
21 - 33 of 33 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.