Alternator
Moderator: Jim Walsh
Alternator
This is probably a stupid question . If my alternator is working, should the needle on the amp meter on the engine instrument panel move to the right side? When I push on the glow plug switch, the meter moves to the left but when the engine is running the meter just stays in the middle on 0.
Amp meter
The meter on my engine panel measures voltage not amps.
If yours is an amp meter, yes it should show a positive reading when the alternator is turning faster than its threashold speed. I mention this since my alternator doesnt put out meaningfull current or raise the system voltage at idle.
The amps (and to a point volts) should increase as the engine speeds up from idle. If not something is not working. I suggest you put a digital volt meter on your battery terminals and check the voltage while running the engine. It should read about 14.4 +/- when the engine is turning 1500 rpm or more. If its 12.6 or less then you are not charging your batteries.
Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.
If yours is an amp meter, yes it should show a positive reading when the alternator is turning faster than its threashold speed. I mention this since my alternator doesnt put out meaningfull current or raise the system voltage at idle.
The amps (and to a point volts) should increase as the engine speeds up from idle. If not something is not working. I suggest you put a digital volt meter on your battery terminals and check the voltage while running the engine. It should read about 14.4 +/- when the engine is turning 1500 rpm or more. If its 12.6 or less then you are not charging your batteries.
Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.
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Oswego John
- Posts: 3535
- Joined: Feb 5th, '05, 20:42
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Ammeter Needle
Something to try.
It just might be that your battery(S) is fully charged and the regulator senses this and doesn't call for additional charging.
Watch the meter very closely as you shut the engine off. See if there is any minute needle deflection at all toward zero.
You can experiment a little. With your motor running at idle, turn on everything in the boat that is electrical. The indicator on the meter should swing to the left toward discharge.
Depending on how high the total amp load is, let the battery run down a bit until you feel that it requires some charging. Then rev the engine up to, say 1,800 or 2,000 RPMs and observe the meter and note whther it has swung over to the right, to charge.
Another thing you can do is place the jaws of a clamp-on ammeter around the heavy wire attached to the alternator. While revving the engine, check the output.
This is a good a time as any to check as much wiring as possible for loose terminals, frayed wiring wiring, loose crimps and any other terminal corrosion. A coating of anti oxidant cream on the connections will help prevent future touble.
Good luck,
O J
It just might be that your battery(S) is fully charged and the regulator senses this and doesn't call for additional charging.
Watch the meter very closely as you shut the engine off. See if there is any minute needle deflection at all toward zero.
You can experiment a little. With your motor running at idle, turn on everything in the boat that is electrical. The indicator on the meter should swing to the left toward discharge.
Depending on how high the total amp load is, let the battery run down a bit until you feel that it requires some charging. Then rev the engine up to, say 1,800 or 2,000 RPMs and observe the meter and note whther it has swung over to the right, to charge.
Another thing you can do is place the jaws of a clamp-on ammeter around the heavy wire attached to the alternator. While revving the engine, check the output.
This is a good a time as any to check as much wiring as possible for loose terminals, frayed wiring wiring, loose crimps and any other terminal corrosion. A coating of anti oxidant cream on the connections will help prevent future touble.
Good luck,
O J