Hello-Need Some Electrical Advice

   / Hello-Need Some Electrical Advice #1  

ChuckInTX

New member
Joined
Apr 20, 2015
Messages
4
Location
TX
Tractor
Farmtrac 45
I have a Farmtrac 45, and it won't start. The gauges generally won't even move if the key is turned, although I have reached underneath and wiggled some wires and they will move and immediately stop. My guess is the ignition switch or some sensor (I think there's one on either the clutch pedal or the transmission) is bad. Maybe some relay, although I haven't taken any sheetmetal off. The battery was taken to an auto parts store and tested. It showed to be fine.

Does anybody have ideas on what might be bad and how to test the components? Or even bypass stuff? I tried to jump across the solenoid, but that didn't work. I'm guessing it was because the clutch/range sensor wasn't engaged..maybe I should wire the clutch pedal down when I jump across the solenoid? I know the range and speed are both in neutral when I tried it.

Thanks in advance for any help.
 
   / Hello-Need Some Electrical Advice #2  
Jumping the solenoid (two big lugs) will usually bypass all sensors, switches, etc to at least turn 'er over. Most place I've seen no start issues is corroded attachment of the battery ground to the frame/engine. Doesn't sound that simple this time, but always check that.

btw, Once the engine is running it should only require electricity to hold open the fuel shutoff solenoid on the injector pump.

A bad switch may reveal itself by jiggling a wire attached to it, showing internal wear/breakdown and intermittent contact. Since most power goes thru' the ign sw I'd focus on it and wires connected. May help to sketch a simple schematic or flow chart, even use colored pencils to draw wires as they are traced/identified.

Clutch, brake, and/or range selector switches are wired in series between the 'start' contacts of switch & solenoid, so follow the path/color from batt onward. Disconnect each switch and test function with a rigged-up continuity tester (battery, bulb, wires) or the ohm scale of any VOM/'megger'. Gauges on/off when jiggling suggest one tiny detail needing attention, and perhaps just getting power to or from the ign sw.

A pic or two might help us diagnose remotely, if you can put a few up for us. Expect to hear more ... tog
 
   / Hello-Need Some Electrical Advice #3  
Sounds like you need to pull of some covers and study how that wire wiggling affects the problem. Could be as simple as a loose wire or ground.

The key switch has a main hot going in, and then probably has outputs for accessories, glow plugs (if controlled by the key), fuel solenoid, and start/crank. The only key switch wire that would affect both gauges and starting is the main hot coming in.

Another thing that could affect both gauges and starting is a ground. And due to their nature -- connecting to a chassis in some/many locations -- grounds are likely to fail.

Could also be one of the hots that has rubbed and shorted to ground, but you'd likely have blown a fuse by now.
 
   / Hello-Need Some Electrical Advice
  • Thread Starter
#4  
I have some pictures. Now, I have no photos of the starter/cables because I don't want to pull the filters and break loose the steel lines until I've tried everything else. Trying to diagnose an electric problem AND bleed the system is too much to deal with, right now. But it may come to it. IDK if these pictures will help, but I've got a little more information to add, also.

IMG_0442_zpswyejavsd.jpg

This is the NSS. I pulled the leads off and tried cranking. Nothing. I jumped between them. Nothing.

IMG_0440_zpsz0yvsxtr.jpg

Ignition switch doesn't have any external signs of problems. That cut wire you see flush with the boot on the IGN hot wire was like that-and I bought the tractor new. So, that shouldn't be a problem. Guess there was a universal harness that didn't require another wire for this model.

IMG_0443_zpsbicqtsff.jpg

The only light that illuminates. None of the working lights work.

After posting this morning, I thought some on things and wanted to look more at the wires. I have already checked all fuses, and none are blown. If htere's any relays, I've yet to find them. I took the ignition off and went to NAPA and another parts house. Nobody had anything close
(or could cross-reference the "Wesco" brand), so I have bought a switch off eBay specifically for Farmtracs.

I mentioned I already had the battery tested and found good and charged-up. Even so, today, I took the battery out of my pickup to try it. Y'all probably have see times when jumping a battery wouldn't work, but swapping another would. No difference.

The most that happens if you turn the key is a weak click. I can't help but think the ignition switch is the problem. Aren't some of the positions on the switch for the light circuits? There shouldn't be a fuel solenoid, as it has a kill cable. Anything else y'all need to know, please ask. Again, my thanks.

EDIT: I'm not sure that wiggling was actually helpful. I might've not had the clutch pedal full depressed, as I was trying to do things for three hands with only two.
 
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   / Hello-Need Some Electrical Advice #5  
Get yourself a test light or volt meter and trouble shoot with that before just replaceing until you find it. Well save you money and time. After you get one or the other and need help someone well be able to walk you thru the system.
 
   / Hello-Need Some Electrical Advice
  • Thread Starter
#6  
^Point taken. Won't be able to do anything until the weekend. The switch is already bought and should be here by the 25th. I'm not going to fuss even if that' not the issue, since it's just $15.00 and I'll have a spare.
 
   / Hello-Need Some Electrical Advice #7  
You may have clutch & brake SSes too but NSS seems not the prob. If any of the connectors on the IS can be pulled loose easily with two fingers they could stand to be tightened up. (slide back cover & pinch slightly)

Battery ground cable can be loosened at frame or engine, squirted with Kroil or Blaster & re-tightened to be sure of good contact. A 'star'-type lock washer can be added & the connection greased once tightened. There may also be a start relay to check, but if the solenoid can't be jumped I think we're past that. (suggests batt gd vs pos fault)

Ignition switches can wear out. Hoping a new one is your answer. :thumbsup: Still here if not. :)
 
   / Hello-Need Some Electrical Advice #8  
Agree on the switch, it's not a bad ideal to keep a spare on hand. It's when you start replacing a starter on a guess.
 
   / Hello-Need Some Electrical Advice #9  
Squirt some WD-40 into the ignition key slot and wiggle the key a bit.
That frees up dried lubricant in switch and assures proper operation of that often culprit.
WD is non corrosive.
 
 
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