Ford 4000 alternator ?

[banc123]

My 76 4000 (rebuilt 2010) is eating batteries. I can jump it and use it, but after it turns off not enough juice to crank again. Alternator is reading 12.8 volts, at the battery when running 12.7. Had the tractor 12yrs and it's never been replaced. Seem so like the alternator is not putting out enough volts, would think it should be 14ish volts ?

It's a 1 wire alternator, what's the best way to get the right one ? Take to Napa, autozone etc... And hope they can ID it ? Or are the ones on line that say for Ford 2,000 3,000 4,000 a safe bet ?

Thanks ...

 

[droptop]

Find someone that rebuilds alternators. The older alternators were built to be repaired, unlike the newer throw-away units. You should be getting 14-14.4 v at the alternator. Most likely problem a voltage regulator or bad diode.

 

[WranglerX]

Does tractor have ALT lamp on dash?.... Does it come on when key first turned "on" (but not started)... Many alternators need initialization through ALT lamp to start charging cycle... IF lamp is burned out most likely alternator will not initialize and work properly....

Dale

 

[banc123]

I believe it has an amp meter gauge, don't think it has lamp that illuminates it.

 

[RickB]

Kinda hard to help because:
No Ford 4000’s were factory equipped with alternators.
No Ford 4000’s were built after 1975.
No factory Ford alternators were one wire installations.
But your voltage readings indicate a no charge condition.
Take your alternator to a GOOD auto parts store or starter/alternator repair shop and have it bench tested and decide whether to replace it or repair it.

 

[banc123]

It was originally a 3000, but at some point a 4000 engine put on it. The guy I bought it from said the guy he got it from put a 4000 on it. When the ford tractor dealer rebuilt it, they confirmed it was a 4000 engine. Every part I've replace I've assumed 4000, but every part is generally 2000,3000,4000,5000 applicable. I thought the dealer said 76, could have been 75 , but again seems parts are same for most years.

The one wire went from the alternator to a amp meter then to the terminal on the solenoid the battery cable is on. There are no markings on it other than in the pic, Delco AS.

I did ask a retired tractor mechanic from the dealer about a rebuild and he gave me the name of a local company that did all his, so I'll check with them tomorrow.

 

[Stimw]

This should help you ID it.
Catalog

The 10SI alternator is very popular for a replacement because of it's simple wiring, one wire!

 

[sd455dan]

It was originally a 3000, but at some point a 4000 engine put on it. The guy I bought it from said the guy he got it from put a 4000 on it. When the ford tractor dealer rebuilt it, they confirmed it was a 4000 engine. Every part I've replace I've assumed 4000, but every part is generally 2000,3000,4000,5000 applicable. I thought the dealer said 76, could have been 75 , but again seems parts are same for most years.

The one wire went from the alternator to a amp meter then to the terminal on the solenoid the battery cable is on. There are no markings on it other than in the pic, Delco AS.

I did ask a retired tractor mechanic from the dealer about a rebuild and he gave me the name of a local company that did all his, so I'll check with them tomorrow.

You might in addition to the other suggestions, check the continuity through the amp meter - It is possible for them to go (open circuit).

A quick test you can do is to bolt both connections on the back of the meter to just 1 post, or just run a jumper from the bat terminal on the alternator directly to the batteries + terminal
then start and remeasure Voltage at the battery while running- after giving the throttle a quick blip- some 1 wire alternators need this to excite them into turning on.

Hope this helps, may not be the problem but is worth a try

 

[Dave M7040]

This 35 amp one wire Denso alternator has solved charging problems for many tractor owners. Buicks among other GM vehicles are using Denso alternators and not Delco.
No need to be blipping the throttle to get it to turn on.

$56 on ebay.com

ALTERNATOR CHEVY MINI DENSO STREET ROD RACE 1-WIRE 8162 | eBay

Abandon all existing wiring. Run a 10 gauge wire from Alternator to the starter solenoid. Done.

You can add a voltage indicator which is completely independent of the alternator. Less than $10 on ebay.

I suggest this one because it ships from the USA and you get it quickly.

DC 12V-24V Auto Motorcycle LED Panel Digital Voltage Volt Meter Display 3 Colors | eBay

Dave M7040