Fickle Electrical Dieties

[cod 121]

Decided to fix a leaky hydraulic hose today on my 418A and once that was done I thought it might be a good idea to clean up all of the residue from the leaking hose.  I had already removed the dash, the cover over the parking brake and to get at the hose fitting I also removed the front plate that holds soleniod in place.  I fired up the power washer and cleaned out all ot crud and then got out the leaf blower to get rid of the water.  Got everything dried out and reassembled all of the items I had removed.  I took a hair dryer to the electrical connectors before I put them back together and once that was done I turned the key and was greeting with silence.  Knowing the the tractor had been running fine before I "cleaned it" I started to go over the electrical connections one by one to see if there was a short, but so far I can't find anything.  I checked the fuses and fuse blocks, each of the leads from the ignition switch and the connections for the hour meter and voltmeter and everything looks okay.  I also cleaned the ground for the battery I can start the tractor with the key in the on postion and shorting across the soleniod but none of the guages work and the head lights won't come on either.

At this point I'm not sure if there's something I've overlooked but I'm definately open to suggestions as mowing season will be here shortly.

 

Thanks!!

[Ed Kennell 42,232]

Is the parking  brake switch hooked up ?

[gwest_ca-(File Mod) 11,532]

Wiring diagram

 

Ignition switch sends power to the pto switch.

Pto must be off to close the start/half of the switch which passes power to the neutral switch.

Neutral switch closes in neutral sends power to the starter solenoid.

 

If your idiot lights work they should show the switch/circuit at fault.

 

Garry

[cod 121]

Ekennell, the parking brake switch wires are in place and I can use Garry's diagram to see if they could be reversed.

 

Garry, unfortunately, none of my idiot lights work but I'll take acloser look at the pto connections tomorrow.  I've got a friend at work who just picked up a set electrical connector files for cleaning the molded in female/male connectors so I might try them just to make sure there's a good connection between connectors themselves.

[Ed Kennell 42,232]

Just saw you have no lights.  Looks like that must be a ignition switch problem.

[cod 121]

Went out today and took a look at the PTO switch. I removed from the tractor and took the ohm meter to them and they appear to work as they should.  I then checked each of the PTO wires and all of them seem fine as there were no shorts that I could detect.  I then removed the ignition switch and tested that and it functions as it should, and rechecked all of the wires and connectors that go with it.  I then tested the wires from both the seat switch and parking brake and they were okay as were the switches themselves.  I put the battery back in and turn the key but nothing happens, not even a click.  The battery has 12.4V and if I jump the soleniod it fires right up.  With the engine running none of the guages worked and the headlights still would not come on.  So I'm still stumped as this tractor ran fine all fall and this winter even if it sat for a couple of weeks. The guages were working as they should and so were the headlights.  Yesterday when I washed out the oil residue I was rather careful about NOT spraying any of the connecters and as I had the dash removed and the soleniod as well, they stayed perfectly dry.  I may have gotten the fuse blocks wet but I dried them out, cleaned off the interior connections and checked them with the meter and they were fine.

 

So I'm back to square one.  I do appreciate the advice and I'll keep checking but for now, the chainsaw is calling to me and it runs fine...

[Martin 2,133]

sounds like a connection problem somewhere. if you can, hold the key over to start and try moving the fuses and relays in front of the battery at the same time to see if anything wakes up. also try moving the molex connector to the engine harness. another problem area. the warning light panel will not affect the operation of the tractor if its good on the lights or not.

fuse block connections, relay sockets and /or molex connector to engine harness would be my guess if the ignition switch and all safeties work out.....

[gwest_ca-(File Mod) 11,532]

Gauges and lights get their power from the green wire on the ignition switch which has a 15 amp fuse in it. Has nothing to do with the starter circuit.

 

Follow the tan wire from the ignition switch to the pto switch. This will have voltage in it with the key in the start position.

If the pto is off the tan wire power is passed to the purple wire with the key in the start position because the pto/starter switch is closed.

The purple wire goes to the neutral switch. That switch should close in neutral and pass power to the light blue wire that goes to the small terminal on the starter solenoid.

 

Garry

[cod 121]

Well gents, I solved the problem and it was really dumb.  There's a red wire that runs from the ignition switch to the solenoid and it helps if you place it on the same terminal that the battery cable it connected too!!!  For some reason I placed it on the same terminal that the starter cable was on and DUH, no voltage gets to the ignition.

I made the switch today and sure enough, with the ignition switch turned on the headlights came on and the engine would crank over.

 

So thanks again for all the help and if I figure out how to wire an IDIOT light onto my forehead, I'll put up a picture.

 

Cod

[Save Old Iron 1,571]

Cod, well done.

 

I'm thinking we have seen 4 or 5 of this exact same issue over the last year or so. Many folks were thrown off course thinking this issue resulted from a pressure washing session. This is a prime example of how sound, systematic troubleshooting will get you fixed long before random guessing and parts swapping.

 

Again, good troubleshooting.

[cod 121]

Being able to come here and ask questions is extremely valuable as sometimes all one needs is some suggestions and ideas to try out or to look for.  It's a great resourse and I really appreciate all of the responses.

 

Thanks guys!

[Graeme 7]

Cod, don't feel too bad, I just did the exact same thing, however, I have you to thank for the solution.