TC33D No Indication of Power Will NOT Start

[ruffdog]

The lights are powered through the 20a F3 fuse, and through the switch (lights and instrument lights). The gauges are powered through the 7a F2 fuse. Do you have 12v at the light switch?

 

[dryflycaster]

I do have some schematics, those in the owners manual and the repair manual. They about the worst designed/laid out schematic/wiring diagrams I have ever had to deal with. They look as if they were drawn on napkins and then taped together to form a complete diagram.

 

[dryflycaster]

The lights are powered through the 20a F3 fuse, and through the switch (lights and instrument lights). The gauges are powered through the 7a F2 fuse. Do you have 12v at the light switch?

I have not taken the console or knee panels off yet so I have not taken any voltage measurements there. There is however voltage at each fuse location in the fuse block and all of the fuses are good.

 

[dryflycaster]

You need a schematic to further diagnose. You seam to know what your doing with a volt meter so I'm sure once you start tracing circuits and voltages you will find your peoblem.

One cheap trick you can try that I didnt hear you talk about is to swap relays around.

I didn't know that there were relays that were the same. I can try that once I open up the console area..

 

[thclimer]

Have you had a chance to to look at my first attachment in post #7, its a pretty good wiring schematic? All on one page unlike the operation manual where it is spread out over several pages.

 

[dryflycaster]

I looked at it. I have that one in my 3-ring binder. It's one of the better ones.
I'll use it once I open up the dash/console. Maybe later today, if time permits. I've got chimney work going on that I need to keep an eye on.

 

[dryflycaster]

Have you had a chance to to look at my first attachment in post #7, its a pretty good wiring schematic? All on one page unlike the operation manual where it is spread out over several pages.

I spoke a little to quickly. I had looked at it and I thought I had a similar one in my paper work from the Repair Manual. I do not. The one you provided is a much more complete schematic/wiring diagram of the entire system than what I have. I'll need to look at it some more and compare it to the voltage measurements I have thus far taken.

Thanks for taking the time to provide it.

 

[dryflycaster]

No Power Follow Up !

It seems as if I took a couple hundred voltage and continuity checks in the attempt to solve my no power problem. All to no avail.

I stopped off at the local New Holland dealer (H&M Amsterdam, NY) and discussed the issue at length. I left there with a new ignition switch. Even though it is considered a electrical component, they told me I could return it as long as all I did was to plug it in and not completely install it. They also suggested it would be a good idea to check the negative cable connection at the frame, which I was certain would not be the problem because I was reading +12 vols throughout the system.

So..... I returned home plugged the switch in with no success, still no power. I then commenced to take a few more voltage measurements that all looked to be OK.

While connecting the negative lead of the volt meter to the connector on the battery something didn't look quite right. A closer inspection proved that there was no cable attached to the connector it self. I had replaced the negative connector (typical replacement connector with two bolts and a plate to secure the cable, 3 or 4 years ago when the original equipment one didn't look very solid. I also installed a cab heater at that time, connecting the cable directly to the positive and negative connectors at the battery. I moved the heater cable out of the way a bit and sure enough there, hiding under the heater cable was the end of the negative cable, that should be attached to the battery connector, still attached to the frame but not to the negative battery connector.

I quickly attached a jumper wire from the adrift negative cable end to the the negative battery post/connector and all power was restored to the tractor.

I was led somewhat astray from this conclusion because I able to get satisfactory voltage measurements throughout the tractor. I believe this was possible without the negative cable being connected to the battery because I was picking up a soft ground through the cab heater I had installed. Not a solid enough ground to allow the system to power up, as it should, but good enough for unloaded voltage checks.

I reattached the cable end to the negative battery connector, reinstalled the dash panel and the kick plates and I now have a running tractor again.

I have since returned the ignition switch.

Thanks to everyone that took the time to offer up suggestions.


_bill

 

[thclimer]

Glad to hear you are up and running again and thanks for letting us know the outcome so that others can also learn what to look for.

 

[etpm]

The OP used only a digital voltmeter and finally discovered the problem was a disconnected negative and what he described as a "soft ground" through a heater. This shows why using a test light is also a good idea. Digital voltmeters put almost no load on the component being tested. This means that they will show voltage present even if it is being conducted through a connection 1/10 the diameter of a hair. This is great most of the time because the meter will not load down circuits that use only micro amps of current. Anyway, using a test light can show a poor ground by either not lighting up or lighting up dimly. The test light should not be a LED because LEDs use very little current. An incandescent bulb should be used. Using a test lamp may have helped the OP find the fault sooner. It's great that the OP posted about the solution, doing so really helps others.
Thanks,
Eric