4440 Alternator problems

looks like a third alternator on my 4440 may be bad. charged both batteries and the tractor starts, but no gauge lights and the voltmeter needle is on zero with the tractor running. if the alternator is bad, can I get something other than a John Deere alternator?

Do you have the Delco? About 7-8 years ago we would rebuild the Delco each year and the dealer suggested the conversion kit. Have not had the alternator off sense them. I can not think of the brand right now but it is made in Japan. It put the Delco to shame.

If the gauge lights aren't working, you have problems OTHER than the alternator.

what your are thinking of is Nippendenso, they are good,, there are other problems with the instrument panel, I have found the resister wire in the harness going up to the alt. a small single strand wire will break in the harness from fan blast or what-ever then the alt. apears bad,,a lot of times I put a 'self-exciting' delco on,, and a hill-billy way of checking the alt. for chargeing is put a screw driver against the rear bearing area , if it's magnatized it's charging..

throwing alternators at it does not solve the problem. You have fuses, or short circuits in the dash, obviously.

Remove the left dash cowl and there is a circut breaker board. Remove the plastic cover and take a 10mm socket and tighten all of the breaker nuts.

I had a 4430 with a Delco altenator, lots of radio static and had to replace brushes quite often. Then I got a new Neehof brushles alternator and it's still on there many years later with no problems. I got this one from NAPA at least 25 yrs ago. Had to alter the bracket slightly.

Sounds like dff has been there. My neighbor was tossing alternators at his 4240. So we had one checked and it was good.

Turns out that the circuit breaker that the feed from the batt post goes to under the left dash cowl was fried. It was making intermittent contct. replaced thst baby and it is happy.

You really need to look there and especially at the first breaker that the feed wire goes to. After all the messing around I would replace that one for the heck of it.

good luck and post back.

Did you check the resistance wire? Or check the firewall connection?

The brown resistance wire from the alternator looks good and after charging the batteries, the alternator seems to be working since I am reading 14.5 volts with the tractor running. all fuses test good. am getting ready to have the accessory relay checked.

the 4240 I wourked on had autoresetting circuit breakers.

On the 4240 it was an intermittent problem in that most times the system would check good until in about two years the circuit breaker fried completely and it went down for the count.

My bet is that if you replace the circuit breaker that the wire that feeds the panel power that originates from the starter that may just be it. That won't break the bank unless you got a long ways to drive to get one.

Never know about the panel relay, that coud be the culprit also.

If the alternator is not getting the batt juice I don't think you will get a charge.

The 42 worked fine until we did not have time to mess with it and then it would not work.

I assume that you checked the polug on the alternator to make sure it had no fasults?

Your alternator has 12v constant at the single "big" post and the plug. The wire labled 1 or ig at the alternator is keyed 12v. If your harness is good and the resistence wire is the problem you can purchase a kit to replace the resistance wire from the plug on the fire wall to the alternator. The kit uses a resistance diode instead of a single strand wire. The diode is replaceable. The two constant 12v wires on the alternator go to the same post on the starter relay on the firewall. I have replaced several engine harnesses on these tractors the last few years, so look closely it may be time to think about a harness. From the starter relay on the firewall the charge voltage goes to the starter by the way of a short harness. On the starter it is the big post that shares the battery cable. From the starter post it charges the batteries. The cab gets power either from a wire off of the starter post or the starter relay. Off hand I think it is the relay. The cab power wire comes in by the load center. It usually is attatched to the bottom of the left buss bar. The left row of circuit breakers are 12v constant. When you turn the key the right buss bar should then have 12v. It is not uncommon for a nut on the circuit breaker to loosen and melt a little plastic between the nut and the connection. Sometimes tightening the nut will help and sometimes you have to remove the nut and scrape the melted plastic from the surface then put the nut back on. What I do to quickly test a circuit breaker is use a jumper wire and touch it between the breaker posts. If the circuit comes on then look at that breaker. I am also pretty sure your volt gauge lead is on the starter relay also. A qick side note. I have had some customers on older combines go through alternators quite frequently also. Most of the time if they take the time to freshen up the wiring over the engine the problem goes away. If your wire is corroded inside of the insulation it has to carry extra amperage. With the heat of the engine this problem is compounded. Just something to think about. Sorry this is so long but hope it helps.

problem solved..probably when I tightened the breaker nuts good.
the breaker fuses all tested good as did the accessory relay switch.