Alternator Amp requirements and other electrical issue questions
 

Just curious what the suggested AMPs are for a new alternator Im going to pick up with my 454 rebuild... Dont have anything crazy, dual batteries, no EFI or MSD box... standard harness AFAIK. Should I replace with standard or something higher??


Also curious if someone could help with some voltage issues Ive had... I think at one point I had an issue with the ignition that I wasnt getting enough voltage and the engine almost stalled out or choked up some... I ran a direct line to the ignition/key switch from the battery and didnt seem to have a problem after that... Also, it seems like my radio wasnt getting enough voltage, turned up too high it would shut down and restart. Did the same thing adding a direct 12v from the battery to the radio and no issue since...
Do I need a new wiring harness or is there is anything else I should be looking into?

Thanks in advance for any advice in both issues!
Chris

anyone???

Stock alternator is fine.70-100 amp is average for boats without loud stereos.
If your radio cut out at high volume levels it is a thermal resistance problem usually caused by bad connections.Start with cleaning all connections, check your grounds.Make sure copper cabling is not black (bad)
BTW your blind without a volt meter.

Start by checking and cleaning all your grounds. Huge alternators and big power wires are futile without ability to form a complete circuit.
Making sure an alternator is ignition protected/USCG compliant is more important than big amperage. If everything is in order and you run 2 batteries and a switch, 60A will suffice.

A radio is very susceptible to a drop in voltage. If you ran the system for a long time or have poor wiring, the radio will be first to shut down. You might need a complete re wire or at least a complete connection check as stated. Start with your main engine harness, then check all the helm connections. You might be surprised, and remember......grounds are VERY important.

Thanks for the replies speedracer and michimike...
Ill start by getting a standard marine alternator, probably save me a couple bucks over a high amp alt anyway....
Ive got the enging out of the boat, so when I cleanup, paint, and re-rig everything, ill check all those connections and cleaning all the grounds to the motor and also up at the helm.
Ive got a volt meter, but not sure how that helps if its got the full 12V till it cuts out?

OK... ill do my best with all the checking of connections... if I still have any issues, I may try a re-wire... What would you suggest in all that?? Get a new harness from the round engine connector to the helm, and from there re-wire everything?

Remember, your alternator is actually putting out upwards of 14 volts. If your gauge reads only 12 ish, you are probably already having wiring issues. I re wired my buddy's helm last year and now his gauge reads 14 and it starts and runs better too.

Ya... I know there were times the voltage guage would show barely 12+ volts yet there was not problem running.... but then others it would show much higher like normal 13-14volts

FYI, myself and several friends have had good luck with this model:

http://www.dbelectrical.com/p-3609-n...e-adr0334.aspx