"Yes, you probably would have
"Yes, you probably would have been better off to have ordered the factory manual directly from Andrew at this site.
The original regulator that does work excepting the gray wire? It's possible that the internal circuit to that gray wire has failed and won't affect any other portion of the regulator BUT that's a unknown factor. I'd use it as a last resort but only until a new regulator/rectifier could be obtained. As mentioned previously, in time a faulty regulator, without fail, always seems to short out with a resulting fire.... a real chancy situation!
These units you're installing that don't work, are they free units that you're obtaining someway? If you paid for them, they certainly should be replaced free of charge.
At any rate, you now know that the tachometer is okay and where the problem lies.
Here's something from my database that may be of interest to you.
(Replace Water Cooler Reg/Rectifier With Regular Small Rectifier)
(J. Reeves)
Many engines, if equipped with a P/T/T, incorporates a water cooled regulator/rectifier assy somewhere, usually located on top of the block, just in back of the flywheel on a V4 or V6. If the battery is not being charged and/or the tachometer is being non functional or erratic, the usual problem is that the water cooled regulator/rectifier assy has shorted out, a fairly expensive item. However, if your engine does not have a high 35 ampere output stator (under the flywheel) but rather has a 6 ampere or 9 ampere stator (amperes in the low range area), then it really does not need that expensive water cooled regulator/rectifier assy.
You can trouble shoot that item by locating the terminal wiring block on the engine. Find the small gray wire that leads to the engine wiring harness (at the present time, it's attached to another gray wire that is attached to that reg/rect assy. Move that gray wire so that it will be connected to the Yellow/Gray wire on the terminal block that leads to the stator assy. That small gray wire that we want moved leads to your techometer. Now, run the engine for a short time simply to check the tachometer reading. If the tach now reads correctly, you may do the following if you wish.
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A rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.
If you have a late model engine with P/T/T, you probably have a water cooled regulator/rectifier assy. That regulator/rectifier assembly has a list price that exceeds (usually) $250.00.
However, the low ampere charging stator on the engine really doesn't require that expensive item. The engine, if it has the low ampere charging stator, usually a 6 ampere or 9 ampere, will allow you to use the smaller type rectifier which is by far a less expensive unit. This smaller rectifier has a list price of approximately $50.00.
I'll enter the original OMC part number and the superceeded number for both units here. Prices are approximate and rounded out.
Water Cooled Reg/Rectifier - 395391--> 395204 - $250.00 .
Regular Smaller Rectifier - 582399--> 583408 - $50.00.
To use the smaller rectifier, remove and discard the wires from the water cooled reg/rectifier. Cut them off at the reg/rectifier and remove them. Don't let them lay around on the engine or connected up at the other end. You can replace the water cooled regulator/rectifier with a plate if available or leave the water cooled reg/rectifier on the engine (let it serve as a water passage cover plate).
The following paragraph pertains to engines up to the time I retired (Approximately 1990). Later model engines might not have a mounting area for the smaller rectifiers or may have the smaller rectifier mounting area elsewhere. I can only suggest you check the engine involved.
Now on many of the 2, 3, V4, and V6 engines, look at the starboard side of your engine right close to the wiring terminal block. There are two threaded holes there where the smaller rectifier attaches to the engine. They're two different sizes (threads) on some engines. Just find screws or bolts that will work properly. After that, pertaining to the three wires that are attached to the smaller rectifier, attach the RED one to the 12v RED terminal on that block, the yellow one to the yellow stator wire at the block, and the yellow/gray one to the yellow/gray stator wire at the block. NOTE, the Yellow/Gray terminal will have the stator Yellow/Gray wire, the small rectifier Yellow/gray wire/ and the tachometer Gray wire.
Some of those small rectifiers do not have a yellow/gray wire, but instead have two yellow wires. In which case, it doesn't mater which yellow wire goes where just so they're attached to the stator wires.
Let us know how you make out."
