What does your Wd/Wd45 show on voltmeter?

Been having electrical problems with my WD45 the last couple weeks. Never had any charging problems for years. Ran all new wires and switches last year.

To Jeff Z's point: make sure that the alternator is charging before you pull it off the tractor and proclaim it dead. Could be that it needs to spin at higher rpm to generate current.

No harder than it is to pull off, after checking the belt tention and wiring, I would take it off and let the parts store test the new alternator. If it test good you got to have a large draw on it some where. Also if it test good ask what rpm it engages, at work we had arrow boards with a single cylinder Lister Petter motors running an alternator for power. Some standard alternator would work fine the next wouldn't engage, so we had the alternator shop set them up to engage at a lower rpm.

What kind of alternator did you put on it? Some of the one wire Delco's have to spin pretty fast to start charging.

I went through 5 alternators on my 73 Ford F100 a few months ago and I finally got a good one the last time. They all say remanufactured in china right on it. So I spent the bucks and got a Ford Motorcaft alternator that said made in USA, works great. Does that tell this country anything??

Yep I did use my multimeter at switches, starter, alternator and at battery. I have a volt gauge in place of the amp gauge. Taking the alternator to town in the morning.

Every one I get says remanufatured in China on a sticker on the side.

You can do really high tech tests on 10 alternators that are all the same and get 10 different test results.

what resistance are you using in your signal line to get it to start charging ???

I'm using a 1N5408 diode. Using it on all my tractors.

Hmm... well, if you're getting alternators that are Made In China, and you're certain that has some bearing on the problem, and you keep putting the same type back in, expecting different results, I'd say you're at LEAST unjustifiably optimistic.

I don't get stuff like that at big-box type stores, because I have an automotive electrical rebuilding shop about two miles from my place... I can carry something in, and most likely, they'll have an identical part sitting on the shelf ready-to-go, and if not, or I have reason to want the EXACT one back, I can pick it up either same afternoon, or next morning, ready-to-go.

Now, and alternator that doesn't charge, particularly after being rebuilt, or newly manufactured, can do so for a variety of reasons.  One thing I would SERIOUSLY investigate, is whether the alternator you're putting in EXACTLY matches what came out.

By this, I don't mean that the part numbers, specs, etc. all come out... it's wether the one you TOOK OUT is actually 'stock', or if it had been internally modified.

Many modern so-called 'upgraded replacements' have totally different output curves from OEM units... the alternator windings are connected in delta, rather than wye orientation, so they develop substantially higher current, but lower voltage, and consequently, they don't charge for pooh at low RPM... and of course, imported electric motors and alternators are frequently not made to the level of precision... they have larger air-gap between rotor and field poles, and consequently, poorer efficiency.

IF you're not getting the voltage output you're expecting, you can install a diode forward-biased in the regulator's SENSE line, which will cause the regulator to 'think' the output voltage is 0.6v LOWER than it actually is, so it'll bump it UP accordingly.  It's not something I'd suggest as a solution to a 12v problem UNLESS you're running some sort of a battery-isolator (like marine and RV systems use to charge two different batteries from one source)... or if you were using an alternator set up for 6v... and trying to charge an 8v battery (it'd take either 3 or 4 diodes in series to do this).

Just some things to consider...