Electrical System Upgrade Help!

[JR_VIC]

I have been restoring and fixing all of the gremlins in my 92 SNCB for the last few months. I am now working on the electrical system. My boat sounds like the other early 90's models with poor grounding in the dash and gauges along with what appears to be inadequate power supply wire from the battery/solenoid up to the ignition switch on the dash. I have just upgrade to the GT40 100 amp alternator and added a second Odyssey battery for the stereo system and that part is working great...it is just the gauges reading inaccurate and/or not supplying enough power needed such as dim dash lights/nav lights/perfect pass flipping on and off with numerous accessories turned on at once.

I believe my boat has a 20 amp ignition breaker/switch at the dash. Others have mentioned that the main power wire from the battery/solenoid up to the ignition switch is too small such as a 12 gauge wire. I want to run a new main power wire from the back up to the front in an 8 gauge size to the ignition breaker. I had planned to change the current 20 amp ignition switch over to a larger 30 amp ignition switch therefore adding more capacity. So here is my question...by running a new 8 gauge wire up to the ignition switch should I upgrade to the larger 30 amp switch or is the 20 amp sufficient in size? I am not an electrical engineer so I don't want to just change to a 30 amp ignition switch and cause a potential meltdown or burn up something. I will also be replacing the entire current blade connectors on the gauges and adding heat shrink along with adding a negative ground wire from each gauge to a ground distribution block to help.

Does all of this sound OK? Any potential problems or concerns? Thanks in advance!

[DanielC]

RE: Electrical System Upgrade Help!

JR_Vic, It sounds to me like you are on the right track. Do not forget the use heavier wire in the grounds, also. I also solder any wire connection I make. Perfect pass systems are known for needing lots of current, so try to get the power wires to it as short as possible, and heavier wires would not hurt. On my 97 ski, if possible I try to bring the ground wires for the shower, and the heater back to the engine block, and keep the grounding load out of the dash panel. Do not put in a higher amp breaker, unless you upgrade all the wires after it. You do not want some wire somewhere becoming the circuit breaker.

[jwhposon]

RE: Electrical System Upgrade Help!

Does anyone know if you can just change the pulley on the stock alternator? Does it actually make any difference? I have a 2004 SAN 210, I think it has a 100amp alt. but not sure.

[nms1991]

RE: Electrical System Upgrade Help!

JWPOSon what are you tring to do? THe altenator on that motor is a serpentine type pulley system, and it should be a standard size pulley, and it should come off the same way as most. On JR VIC problem he is on the right track of his electrical problem but he stated he was updating the ignition switch to a 30 amp version, do you mean a ignition breaker or key switch? One of the Better ways of rewiring the dash is to run the power wire from the battery to the dash thru a breaker or fuse, than going from the motor to the dash shorter run of wire. And yes you want to use solder and shrink tube on all of your connections as that is the only way to do a electrical connection on a boat.

[ABEL]

RE: Electrical System Upgrade Help!

would you be willing to post pictures of where you mounted your second battery? i am in the process of putting a second battery in our 1991 SNCB and would like to see what others have done before i make any final plans

[jwhposon]

AS soon as I get home tonight.

[jaybird]

What is overlooked in a 12VDC system is the voltage drop, if you upgrade to 8 ga power and ground the 20 amps breaker will be fine. The problems with the older boats was the small wire creating voltage drop which a new breaker will not affect. Its unlikely you will ever pull over 20 amps unless you run several ballast pumps simultaneously. If you upgrading your sound system with new amps they will need to come from the battery direct anyway. If the 20 amp trips you can always upgrade it later, no harm in having a breaker that is on the low side however yes the 8 gauge is OK for 30 amps up to 11 ft. and 20 amps for 16 ft. to keep the voltage drop with reason.

[Mikeski]

http://shop.genuinedealz.com/Marine%...%20Cable%20RB/

[8122pbrainard]

Re: RE: Electrical System Upgrade Help!

Does anyone know if you can just change the pulley on the stock alternator? Does it actually make any difference? I have a 2004 SAN 210, I think it has a 100amp alt. but not sure.

The nice thing about a alternator is power output is consistent just past engine idle. This wasn't the case with the old generators as output increased as rpm's increased. It's the reason we have alternators! The only time a smaller sheave (pulley) is used on a alternator to increase it's rpm is on engines that idle a lot like on a UPS delivery truck. You should have plenty of power with the 100 amp. Don't mess with the sheave.

[ABEL]

RE: Re: RE: Electrical System Upgrade Help!

pictures? im stuck on if i should install a second battery in our 91 SNCB would be very helpful to see what others have done..

[Chexi]

RE: Re: RE: Electrical System Upgrade Help!

What I did was put in 2 Optima blue top dual batteries plus the Blue Seas battery switch and relay. I also purchased quite a bit of wire from genuinedealz.com thanks to Mikeski's prior recommendation. Very nice quality at an affordable price.