TC40D Needs bigger alternator

[TCowner]

I finished installing the Curtis Cab on my TC40D but I think I need more output from the alternator. I have 4 fifty five watt work lights, defroster fan, windshield wiper and the two-speed heater fan. This plus the tractor headlights and taillights must be pushing the alternator's 40 amp output to the max. When I have everything running I notice the tractor laboring a bit especially at lower throttle settings. The lights seem to dim a bit and the blower fans slow down when every accessory is being used.

Has anyone installed a larger alternator on their Class III New Holland?

 

[thcri]

I think there is an alternate heavier duty alternator for the TC series tractors?? Gee that is a load to say!!! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif But I think even with the heavier one you may find it falling behind with everything you have. A larger battery if you can might help the situation and you may find shutting everything down and leavng the tractor run some to make up will help.

murph

 

[AndyMA]

From what you're describing it sounds like the alternator is sized about right. Remember the load (all your lights etc.) are basically running off the alternator (not the battery) when the system is charging. This load is being transferred directly onto the tractor engine hence the reason you are seeing the tractor engine lug down. Assuming the same alternator efficiency, exactly the same load would be transferred to the engine whether you have the 40 amp or lets say a 65 amp alternator . Without measuring the current draw it's difficult to say, but a first approximation to the situation would be to put a good voltmeter on the battery terminals and monitor the voltage as the loads are added. As long as the voltage stays on the plus side of 12, the alternator is charging the battery. When the voltage drops below 12, the load current is being partially delivered by the battery. This test will give you a good idea if your alternator is large enough. If you go to a larger alternator and pull more current the tractor engine will just lug down further.

Andy

 

[mahlers]

It wouldn't hurt to start looking into a bigger alternator - if you're close to max capacity on your stock unit (40 amps), it'll probably go out on you sooner rather than later. Another thing to look at is how the cab's systems were wired into the tractor electrical system. If you're sharing pre-existing circuits, you might be pushing the OEM wiring to its limits which would definitely exhibit the symptoms you mentioned. If it's wired directly into the main power, then the dimming and blower-slowing is a sign that your alternator is at its limit.

It should be relatively easy to find a replacement alternator - try getting a cross-reference from the existing one or finding a compatible unit from the mounting measurements. Then, go to your local Kragen (or whatever they call themselves in your neck of the woods) and get one of their lifetime-replacement units for around $40. You'll probably need around 65 amps - and if you use your tractor for short bursts of work in cold weather, an 80 amp alternator wouldn't be a bad idea. You'll notice the extra occasional load on the engine at idle, but I think the governor in the engine should keep things running just fine.

To figure out the size of alternator you'll need, just take the total power load (watts) and divide by the system's voltage (12 volts nominal). In your case, with around 680 total watts of accessory load, you'll need about 57 amps just to run the accessories at full load - and then you need around an extra 10 amps to charge the battery. So, 65 amps should do OK.

 

[TCowner]

I ran a 12 guage wire with fuse from the batter to a 6 gang rocker switch panel that I ordered from a boating supply company (Overtons). I put a 5 amp fuse on five of the gangs and a 15 amp fuse on the 6th which is where I feed the two-speed heater fan. The rocker switch panel is rated for 30 amps.

I ran the windshield wiper, defroster fan, left front work light and right front work light to 4 individual circuits on the rocker switch panel. There is a circuit that is unused. The 2 rear work lights don't run to the rocker switch panel but instead are wired to the tractor's wiring harness behind the seat.

I really don't mind working the tractor a bit if I go to a larger alternator. I just want to make sure that I don't drain the battery so that I have a problem starting the tractor. John Deere offers a larger alternator on their compacts so it shouldn't be a problem on the TC40D.

 

[mahlers]

The 12-gauge wire and rocker/fuse setup sounds like it will work fine. You are right at the rated limit for the rocker panel, but they have a big margin of error built into them. You might be at the limit of the fuse for the defroster fan - if it draws anything more than 70 watts it'll need an 8 or 10 amp fuse. If you're running at full voltage, it won't be a problem, but if the system draws down you run the risk of blowing the 5 amp fuse when the defroster fan runs.

I *think* that the 65 amp alternator might be available directly from NH since it's standard issue on the cab models. I would guess that they'd use a corporate standard on all models, but I've been wrong about that in the past. It will be expensive, though... You might want to ask for the part number and then cross reference to something easier to get since I think they still use a relatively standard Ford/Motorcraft unit. They might also use a Denso alternator - which are extremely common and easy to cross reference.

Another thing to consider is to install bypass harnesses for your work lights. That way you're not running the full current through the rocker panel - it comes direct from the battery and goes through heavy-guage wire to the lights. I've got them on all my vehicles and you'd be amazed at the improvement. Normally, there was about a two-volt drop between the battery and the lamps with the stock wiring, and with the bypass, the drop went down to nearly zero. The lights are much brighter and more efficient.

 

[MackAttack]

Can you post some pics of your tractor with the new cab and electrical panel? Where abouts do you mount the heater??

Thanks
John Mack
Auburn NY

 

[PineRidge]

TCowner I have been curiously following this post because I also have a TC-40D and plan on adding some additional aux. lighting for the upcoming summer. Please keep us posted on your progress regarding your hunt for a larger alternator. Thanks /forums/images/graemlins/grin.gif

 

[djradz]

Terry, you should be able to easily figure out your alternator needs. To start with, the lights alone are drawing 18 amps. >> 55w x 4 = 220w. 220w/12v = 18.33 amps. Do the same with all the other loads. If the heater or defroster have their own internal heating elements, and don't just use engine heat, I can just about guarantee you'll be over and in fact, maybe even with a larger alternator. If not, you'll just be looking at the blower motor loads, but that's nothing to take lightly either. If they already give the loads of these in amps, it's just that much easier - just add them all up. Anyway, hope this helps a little. ...Duane

 

[LoganWildman]

If I was you, I'd replace that 12 ga. feed wire with a 8 ga. Twelve ga. wire is only rated for about 23 amps max, and that depends on the ambient temps. From what you have described, you are at its max or overloading the wire and are at a high risk of it causing a fire.