'01 SAN Upgraded to 100amp Alternator, but still got under 12v at dash gauges

[charlo33]

I own a 2001 SAN. I upgraded to new factory 100amp Alternator, but still got under 12volts at dash gauges.

My problems are:
- The volt gauge & perfect pass still show below 12 volts.
- The Main switch under the dash (the one that connects bilge pump as well) keeps disconecting from time to time when the boat is running. And I have to reset it, then the boat runs again, until it happens again...
- If using bilge pumps + perfect pass + radio = reset + reset + reset...

Do I have to upgrade any wires to dash as well? Any other change that I need to do, i.e. circuit breaker?

[NautiqueJeff]

I would look at the ground wires running from the dash.

[TX-Foilhead]

i don't know about the more modern boats, but in my 93 the wiring o the dash was undersized, I ran a new 10ga wire from the big circuit breaker on the motor to the dash for the hot . I ran the ground from the engine block to the dash, and I got an extra volt an a half on the guage. Made all the difference in the world with the PP which would shut of due to low voltage before.

[charlo33]

i don't know about the more modern boats, but in my 93 the wiring o the dash was undersized, I ran a new 10ga wire from the big circuit breaker on the motor to the dash for the hot . I ran the ground from the engine block to the dash, and I got an extra volt an a half on the guage. Made all the difference in the world with the PP which would shut of due to low voltage before.

Sounds logical to me to upgrade the actual wire to a 10ga, but not upgrading the 20amp breaker under the dash to a higher one.
Will try it this weekend and hope that extra volt and a half being displayed at the gauges.
Thanks & I'll let you know how it works!!!

[charlo33]

I would look at the ground wires running from the dash.

Thanks for the advise, Jeff. Willl look at the ground wires for an upgrade. Rgds.

[seth]

Did you have any trouble with the spacer/spacers lining up? I tried to do this upgrade to my 01 but the spacer they sent me was too small and the pulley was hitting the alt. and then I was told to put my old spacer on with the new and it was too much and started burning belts. Even took it to the shop and the mechanic spent an hour trying it and talking to PCM to no avail. Ended up sending it back.

[DealsGapCobra]

Have you checked the voltage at the battery or any other locations? I would start to isolate where the problem is before you start changing stuff. I don't know what engine you have in your boat but if the alternator uses a separate voltage regulator (older Ford cars did) that is the first thing I would check.

[vr6mole]

Its the wiring to your circuit breaker as someone had already said.

Just run 8 or 10 gauge to it and youll be fine.

[WakeSlayer]

Its the wiring to your circuit breaker as someone had already said.

Just run 8 or 10 gauge to it and youll be fine.

Correct. I have yet to do this, but did the alternator and checked everything else. The project has just not made it to the top of the list yet. This is a widely known problem on some of the boats of that era.

[h2ohangtime]

Dumb question, but when you guys say to run 8- or 10-gauge wire from the circuit breaker, you're talking about from the circuit breaker to the ALL-ON/OFF/AUTO-BILGE switch, right?

[charlo33]

Did you have any trouble with the spacer/spacers lining up? I tried to do this upgrade to my 01 but the spacer they sent me was too small and the pulley was hitting the alt. and then I was told to put my old spacer on with the new and it was too much and started burning belts. Even took it to the shop and the mechanic spent an hour trying it and talking to PCM to no avail. Ended up sending it back.

I installed the new spacer that came with the 100amp Alt Kit, and I had no problems with it. But thanks for the advise, I will check out this issue this w/e. Let you know if I find something abt it.

[charlo33]

Dumb question, but when you guys say to run 8- or 10-gauge wire from the circuit breaker, you're talking about from the circuit breaker to the ALL-ON/OFF/AUTO-BILGE switch, right?

Yes, the one located under the dash.

[AirJeff]

We have an '02 Air (DD) and have similar problems. Battery voltage will be 14v steady, but at the dash it's 11.75v or so. If you turn on the heater, lights, pumps or shower it goes lower. We tried an upgraded ground but that didn't help. We put a 12awg wire to the black box and it helped some, but still not perfect. If we put the 12awg directly to the dash(when running) we get the full 14v. Seems like the black box is zapping our power. What we will end up doing is putting PP, bilge, ballast fill, ballast empty, lights, heater and shower all on 12v relays(with the fuses) with a large dedicated wire for power. I guess we might just do the dash too(or combine with PP), that way it shows true voltage.

[charlo33]

Thanks Jeff. You described the problem so accurately. It's exactly what happens.
Will be working this w/e on it and let you know the results next week. Rgds, CM

[vr6mole]

Yes, the one located under the dash.

NO, you do this for the black fuse box/circuit breaker. Not the switch.