Alternator-what are good signs that it is on the out

SST

SST

Well-known member
Last month, as I was "inspecting" everything before I launched, I noticed that the drive belts for the alternator and power steering were showing wear, especially the alternator. So I replaced them. At first I don't think I had the alternator tightened down enough. While out, I thought I caught a whiff of rubber. But at the same time, I passed behind two boats that weren't operating normally, so I'm not sure where the whiff came from. When I pulled the engine cover off, it seemed kinda loose and maybe rubbed up against the bracket. So, I got it tightened down some more and lightly hammered the bracket just about 1 mm to move it away from the belt. Seems ok. But,

When the fishfinder was working it always displayed 13.1v. I never really looked at the boat gauge much. But without the fishfinder, I rely on it now. But its indications don't seem steady. When I first prep to launch, I run the blower for a few minutes, and then start. When it is running, the gauge drops to 11.5v and only moves when I engage the drive. When the throttle is moved for/rev the gauge jumps to 13.5v. As I'm moving along the gauge drops and pretty much remains around 12.6v. When I put a meter to the battery, it is at 12.6v whether the engine is running or not. Haven't tested it at cruise. The throttle is somehow electrically connected to the instrument panel cuz whenever the throttle is moved most of the gauges jump.

Thoughts?
 
When you increase the rpms, it also increases the amps that your alternator is putting out, which may change the way your gauges read. I'll have to check mine the next time that I am out.
 
Before I hooked up the charger, the battery displayed 12.6v on the test meter. Then I hooked up the charger and it also read 12.6v before I hit the charge button. Shortly after that the charger indicated 13.1v and a bit later was back at 12.6v. I presume the battery is okay as it is only 1year old.

I just want to make sure the alternator is working before I launch into Lake Ontario to Toronto. It’s a long tow home. 😊
 
SST said:
Before I hooked up the charger, the battery displayed 12.6v on the test meter. Then I hooked up the charger and it also read 12.6v before I hit the charge button. Shortly after that the charger indicated 13.1v and a bit later was back at 12.6v. I presume the battery is okay as it is only 1year old.

I just want to make sure the alternator is working before I launch into Lake Ontario to Toronto. It’s a long tow home. 😊
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For the same reason, that is why I hooked up an amp gauge. When the amps are high, the volts are low, and when the volts are high, the amps are low.
 
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