2004 TC40DA battery light on dash,other electric issues

[kartingdad]

HI GUYS hope some one can help,
I was pulling logs there a bushy area today and I noticed that i couldn't shift from low to high range, then see the battery (ALT) light on the dash came on and when I set the parking brake the tach quit working, when I released the brake, tach came back on. I shut it down thinking maybe I ran a stick up into the belt, but that was fine, tractor started right back up, but the light is still on and still can't shift from "LOW TO HIGH". Were do is start looking??????Thank a bunch Don

 

[Down South]

Sounds like a stick may have gone into the tractor and snagged the wiring harness, pulled / broke a connector or cut a wire.
Do a thorough inspection especially under the panels.

Ds

 

[kartingdad]

found fuse number 5 was blown which is Cruise control, high, low, shift and instrument panel, put in new fuse and they again worked, but now, "WHY"?????

 

[Down South]

intermittent or temp short. coincidence ?

Ds

 

[kartingdad]

tried to find every wire that is even remotely exposed or on that circuit, found nothing that looks "BARE" or damaged, will see tomorrow when I start to skid more logs

 

[jinman]

Kartingdad, I can see why this is confusing, but I also think I may know the source of your problem in theory if not in detail. Fuse #5 provides the battery power for the alternator light by feeding power through the light and back to the alternator as excitation. When the alternator begins to work, the voltage supplied by it is equal to the light voltage from the battery and no current flows. Thus, the circuit is in balance. As soon as the alternator stops working, the battery power supplied can find a complete path to ground and the light illuminates. That's the reason the alternator light illuminates when you turn on the key before starting the engine.

With the alternator not working, you also do not have any input to your tachometer. The alternator sends a pulse train to the tach at a frequency proportional to how fast it is spinning. The tach translates that into needle movement. So, if you don't have alternator excitation, you also will not have any tach.

Fuse #4 supplies power to the parking brake light, but it's ground path is tied to the same grounding point as the cruise control magnet. That same ground is used by the cruise control magnet and hi/lo shift circuits. So some things powered by fuse #4 have the same grounding point as items powered by fuse #5. If that ground point is loose, dirty or has any resistance, a tiny amount of voltage can find a sneak path back to the fuse #5 circuits. This is normally a tiny amount of power because the sneak path has resistance. However, it takes virtually no current to get the alternator excited and suddenly the tach starts working and the alternator light goes out. In other words, your tractor's circuits just fooled you with "smoke and mirrors." Poor ground connections and sneak paths for power can be some of the most frustrating things to troubleshoot.

So why did your fuse #5 blow in the first place? My guess is it is associated with the cruise control magnet or the hi/lo shift solenoid under your left side operator's platform. I'd try to get a flashlight and look at the wiring for the magnet under the right platform and the hi/lo shift solenoid wiring under the left side also. Most likely it is not associated with the parking brake because fuse #4 supplies it's power and fuse #4 did not blow.

That's my theory. It may be a fairy tale or it may be fact, but it does add some level of possibility to the problem as you described it.