Port Voltometer? Bad alternator?

[SabrToothSqrl]

On my dash, I'm missing what should be a voltage gauge for port. Which is also my house battery on my 2001 292.

I'm just wondering if it was Formula that omitted this, or the guy who had it before me and redid all the gauges. He did a lot of 1/2 ass stuff, (some even 1/4 ass) so it wouldn't surprise me if he just skipped 1 gauge if he could.

Anyway, the issue is that port really didn't want to start last time out, so I put in a new hybrid battery, since it's starting and house on one. Then after I cleaned up and put away all my tools, and wanted to go for a quick trip out... starboard. CLICK. CLICK. Nothing. I bridged them and it started, but then thought better of it, and just went and got a starting battery for it. same day. So now 2 brand new batteries. (Old ones were from when I got it, so maybe 2017)

Both ran fine for a few trips across 3 days.

Today, after lunch, battery switches off, Port. CLICK. WHAT. THE ... FUDGGEE?

I got starboard started, bridged, and still no start. I rev'd Strb up to 2k and let it charge up port for a few min. started port, and un-bridged the batteries.

Drove back to home base, and batteries off, went for a swim, and an hour or so later, both fired up fine.

Port Alternator was replaced when it failed causing the engine to be unable to be shutoff with the key in 2019. OEM. So, while I suspect it could be failed/failing, I'd hate to think I got 2 years out of it.

Starboard Alt was replaced 2021 due to belt squeal.

TLDR: I'm going to put a multimeter at the battery and at the alternator engine off/on soon as I can, but WHY ISN'T THERE ONE ON THE DASH?!

In 5 years at the marina, I've never had/used an onboard charger. We sit all day with radio on (not blasting) 4-6 hours, and 99% of the time it would fire up just fine.

Interestingly: Port used to stall at hot startup, with varying RPM, even after a NEW base engine, fuel pump, pressure reg, plugs, distro, wires, fuel cooler, etc. etc etc. etc.

Anyway, now it hasn't stalled once, so I do wonder if while the battery started it, it wasn't strong enough to fully run the fuel pump while at low idle, before the alternator could take over at higher RPMs. Because usually if I gave it just a little throttle, it would run up fine. so alternator had put out more power to run the pump? just a theory.

anyway, good times.

 

[AllDodge]

With port running can you measure 14.5V at the Bat?

With getting a click and then nothing and Bat is showing 12.7V (motor not running) it might be the slave relay, key switch or bad connection like the ground

Its not a Bat issue

 

[SabrToothSqrl]

Sorry, click was a poor word choice, Its connecting the starter, but doesn't have the cranking power. I should carry a multi-meter with me, so if it occurs again, I can verify battery level. (as either Formula did not provide a gauge, or previous owner removed it). After bridging them, running strb at 2k for about 2 min, it charged up port enough to get port running).

I do know if it's low enough, my radio actually shuts off as to not kill it.

Using the factory manual, I took some readings, and am now even more confused over the


voltage test.

From my readings below, everything looks 100% normal. Other than the AC test. Googling shows that a lot of cars (not many results for boat) have the same observation. Since both sides showed the same thing, it's hard to justify that it's 'invalid'. I did tighten the belt on Port, but do not suspect it was overly loose, it was just more loose than strb.

Took the boat out after all these tests, ran just fine. drove for approx 30 min. radio all day, started to reposition, then radio another 2 hours, started just fine, 30 min back to marina, restarted to flush, just fine.

I have a lead on a new alternator, but I'm not seeing proof it's failed.

I could see a possible loose wiring or other issue, I did replace both engines 2 years ago, but the grounds are on with large locknuts. I can verify, but don't think these would have moved, but certainly if it does it again will look!

 

[AllDodge]

Manual list 13.8 to 14.8V as normal, but the low 13.8V is only normal if its just started and idling. Once motor goes above 1800rpm, then you should see 14.5V at the ALT or starter post. If boat has an isolator then there can be a 0.7V drop at the Bat so 13.8V. If boat uses a ACR then should be closer to 14.5V

I would look closer at the ground cables

 

[SabrToothSqrl]

Agreed, 13.8 is on the low side. Interesting both show this on the battery posts.

I will check voltage at the alternator. at idle, 1400 and 1800.

Neither side - that I know if has an isolator or ACR. Each is 1 engine, 1 battery, each has a on/off switch with a 3rd for bridging for emergencies.

Always something! I can't imagine both would be showing identical at the same time, if one side was not working correctly.

I'm thinking at this point there is either no identifiable issue - or (worse) it's an intermittent issue.

But, I'll still do some tests and keep a meter on the boat until proven otherwise.

thanks

 

[AllDodge]

I've got 4 hand held meters and just found out the one I keep on the boat reads about 0.5V lower then the others. Was chasing a ghost for years till I happen to use one of my better ones

 

[SabrToothSqrl]

I've got 4 hand held meters and just found out the one I keep on the boat reads about 0.5V lower then the others. Was chasing a ghost for years till I happen to use one of my better ones

I chased an under-performing sea-doo engine for 2+ years, almost drove me insane, stressing my relationship with my girlfriend, and came within inches of sinking or selling it. (the ski, the girl would be harder to sink).

It was... the jets in the carb. Which, my "friend" assured me 10x he checked on multiple occasions.

Knowing everything else was 100% perfect, I replaced the entire carbs, and when I went to transfer the old jets to the new carbs. I identified the issue and bought new correct jets. Then, it ran perfectly for a decade.