Charging circuit BB140A

"Ok the carb problems seem to

"Ok the carb problems seem to be behind me. Now it doesn't appear that the alternator is charging.
Ths instrument panel has an ammeter which doesn't move off center position, seems to be frozen. I put my multimeter on the battery and get about 12v with the engine running and with the engine off, which says to me that the alternator isn't putting out. The battery has been cranked a lot lately and should be pulling in considerable amps to recharge.
I do not have the exact schematic for this engine. What is the little single pole relay by the fuse above the starter? What should I be looking at before I pull the alternator off for a trip to the pros at Yankee Elec?

Thanks again,
Jon"

"Jon,

If I remember correct

"Jon,

If I remember correctly, the AQ140A (which engine should be the same as the BB140A) came packaged with a SEV Marchal brushless alternator. There are three wires going to that alternator: a red one going to the (+), which also goes to the large post in the starter; a black one going to the (-), which also goes to ground; and a purple one with a resistor going to the flat pin by the regulator, which is connected on the other side to either to the ignition switch via the ammeter, or to the (+) of the ignition coil. If your alternator is an SEV Marchal, make sure that yours is connected that way. If all is OK, the ammeter should show charge, and the voltage in the battery should increase when revving-up the engine.

The single pole relay (if it is number 42 in the link) is energized when you turn the ignition key to "start" and it closes the circuit between the battery and the starting solenoid.

http://www.volvopentastore.com/ELECTRICAL_SYSTEM_AND_INSTRUMENT/dm/store_id.366- -session_id.900443121--cart_id.010876839--category_id.333007--list_time.11796339 07--view_id.325861


I think you can probably be guided by the schematic for the AQ140A in the operator's manual downloadable from the VP site."

"Correction:

According to S

"Correction:

According to Seloc, the wire to the (+) of the alternator should be orange; the one to the (-) should be black; and the one to the exciter (flat pin) should be dark red."

"Thanks, I checked everything

"Thanks, I checked everything this morning. All is wired properly and shows continuity everywhere it should. The alternator goes to the shop tomorrow. More money.....
I am upset with myself for being seduced into paying too much for this boat. It has had almost no use in 27 years and is in showroom condition. I should have known that there would be problems from not being used. Luckily I can do all this myself. I'd be out a bundle of money if I had to hire all this work done.

Jon"

"Jon, if you are using a SEV M

"Jon, if you are using a SEV Marchal alternator, try to connect the wire to the flat pin by the regulator without the resistor. This is the way I ran mine for a long time, because there was no way the alternator would get field excitation with the resistor in place. But before you go that way, you may want to take the alternator to your shop bench and verify that the regulator is correctly installed and that the wiring connections are in good condition. The Seloc repair manual (VP sterndrives 1968-1991) contains a detailed procedure for this.

If you find out that the regulator is faulty (common problem) you are probably better off purchasing a different type of alternator rather than sending this one to the shop, as the regulators are more expensive than a replacement alternator (this is the advice I got from the owner of the alternator shop who repaired mine years ago). A Delco MES-3141M-D is larger and of higher amperage than the SEV Marchal, but it will fit your engine (I had one installed in my AQ140A). The cross reference for Sierra is 18-5970


http://www.mesmarine.com/3141m-d.html

http://www.marineengine.com/newparts/part_search.php"

I did check the resistor befor

I did check the resistor before I pulled the unit off. I had 12 v before the resistor and maybe 10.5 after it. Not being able to read the resistance value off the resistor I just figured it was doing what it was supposed to. I will try with it removed. The voltage regulator does not look to have been disturbed but I will check the wiring.
Thanks for the info on substitution units. I'll go with the Delco if it comes to that.
Film at 11:00.......

Jon

"In 1981, I paid 80 bucks for

"In 1981, I paid 80 bucks for a regulator for the Marchal alternator (AQ-140A). Yeesh."

"They were able to get me a re

"They were able to get me a regulator, I pick it up tomorrow. He thought about $60.00 but I'm guessin it will be more than that. I'll let you know. The alternator otherwise bench tested perfect so it is worth spending the money for a regulator.

Jon"