New Holland TC35D dead electrical system

[jinman]

Or maybe Jim Inman will just jump in and tell you what's wrong - your best bet!
Jim

Wow! You set the bar pretty high for me, Jim.

Tractorblue, your TC35D has several things that can drain the battery, but troubleshooting that problem seems secondary to finding out why you cannot start your tractor. I would take a wire jumper at the starter and jump between the big terminal lug coming from the battery and the small terminal (solenoid) to see if the starter will operate with the proper signals. With the key turned off, your tractor won't start, but the starter should operate if all the batter terminals and wiring are good. If this doesn't work, you need to find the bad/loose/dirty cable. Also, do you have a test light or a voltmeter? Being able to check for 12 vdc throughout the circuits is pretty important.

Yes, your tractor could stop instantly if the battery is disconnected and your alternator is not working. The alternator requires excitation to operate. It normally gets that from the battery through the Alternator light on the instrument panel. I would say that if your alternator light has not been illuminated and your tach has operating, your alternator is fine. However, your key switch is VERY suspect. If it is bad, then it could easily be responsible for your tractor not running or dying while operating. The problem with an electrical failure is that it de-energizes the fuel solenoid and the engine dies instantly as if you've turned off the key. A working alternator should keep this working, but a bad key switch could be opening and dropping power to your tractor.

The things you can do without a meter are to look carefully at your seat switch. The seat switch will allow the starter to operate, but it disables the fuel solenoid. Often when I hear of a tractor dying while operating, I think of the seat switch. If the starter operates, but the tractor won't start, the seat switch is the likely culprit.

Next, look under the left side of your operator's platform near where your range shift lever goes into the transmission case. You should see a plug with two wires. This is the neutral sensing switch. If the wires to this switch are damaged, the starter will never operate. Also, look from behind the tractor on the left side to see if your PTO sensing switch wires are intact. You can just see the wires/switch by looking between the wheel and on top of the rear differential.

After you check all these things, post back if you don't find the problem. If so, you'll have to do some troubleshooting with a light or VOM to make sure you find the source of your problem. Let me know and I'll try to help.

 

[tractorblue]

Been real busy and havent had alot of time to troubleshoot. I replaced the key ignition switch with much anticipation... UNfortunately still no power. (FYI the hazard lights never worked as suggested by others). I'll take Jims suggestions and report back. Thanks All !

 

[tractorblue]

Finally have had a chance to do some truble shooting; unfortunately I've not resolved the issue. Once again all fuses are good. I replaced the key switch and I changed out the postive battery post connector ( I bought a negatrive cable/connector but can't unscrew the old one at the chassis...too tight) I get 12.+ volts at the battery. I jumped the starter with wire and the starter did crank (rules that one out). I checked the PTO switch with a continuity tester and it is operating (have not checked for voltage). I checked the seat switch with continuity tester and the switch is closing however I do not have voltage to the seat switch. I still have no panel lights and the head lights and hazard lights do not operate either.
Its hard to trace the source of the seat switch wires so not sure where to look. Jim mentioned the fuel solenoid (not sure where that is) but wondering if it could be bad (not sure how to test it)??? Any suggestions for next sequence of trouble shooting?
I've got a long labor day weekend and 12 acres I sure would like to be mowing .... its my mental therapy time!

 

[jinman]

I think it's time for you to check fuse #2 again. If you have no power to the seat switch, it indicates fuse #2 is open. Power comes directly from fuse #2 to the seat switch, so you should have read 12 vdc if the key switch is on. While you are checking fuse #2 and have it removed, check the fuse socket for 12 vdc on one leg when you turn the key to Run. I really think you have a bad fuse that you didn't notice the first time around.

 

[tractorblue]

Jim,, Fuse #2 calls for 8Amp... I had a 7.5 in there for years and worked...(8A is hard to find) I checked all fuses visually 3 seperate times... I replaced #2 last yesterday with another 7.5A and still no changes since my last post. I have not tested the fuse panel connections for voltage but that is my next step. Thanks alot !

 

[jinman]

Drop in a 10 amp fuse or a 10 amp self-resetting circuit breaker. The circuit breaker is the best solution. I'm not sure where your problem is, but checking that voltage at the fuses is a good first step to make sure the key switch is doing it's job and sending power to the bus.

 

[tractorblue]

(I thought I posted this a few days ago but must have been an upload error) SUCCESS !!! I found two problems, the number 1 issue was that the main 40Amp fuse socket was cracked and the positive wire lug in the back was dangling out of my view. I connected it to the fuse and alas I had power to the dash panel. I still had issue with cranking and after checking the PTO safety switch with a buzzer I found that it was intermittantly closing when depressed. Fortunately I had a spare switch and replaced. I got to mow all 12.5 acres and use my boxblade on the gravel drive this holiday weekend. I want to thank everyone for their input on this post; (sorry I was'nt a little more diligent to catch this simple problem sooner) I love this forum it has been so helpful on many occasions. It is refreshing to see so many people take their time and share their knowlede and experiences to help some one (knowing their not gonna make a buck off of you.... thats AMERICANS!)

 

[jinman]

:drink: Congratulations. I'm so glad you took the time to troubleshoot this slowly and with logical steps. You did great!

 

[AnneReynolds]

I read the entire thread on your electrical problem. We have the same tractor and the electrical system is plagued by gremlins, so I was interested in your experience. We have bypassed all the safeties, replaced the switch (assembled badly at the factory), the 40amp fuse location is tricky too. I bought the 1300-or-so page service manual and the page that should be the electrical schematic says "artwork not available". Last time it would not start, we found that a relay was loosey-goosey. We had to take stuff apart to even get to it to check. We just never know when we shut it off if it will start the next time. Every time we figure out a problem we think we've got the starting issue solved for all time.......yeah, right. Do you still have your TC35D?