SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Squirrel Master on February 04, 2015, 01:28:25 PM

Title: Electrical issue
Post by: Squirrel Master on February 04, 2015, 01:28:25 PM
So I have an electrical issue and I don't know what is the problem I have a brand new alternator it's only 60 67 amp something like that and when I have 12 volts and I'll pull my switch to run my fuel pump I lose 2  volts and when the motor is running I don't gain those two bolts back and when I shut my motor off and I try to refire it it always is a dog just rotating slowly any thoughts fellas?
Title: Re: Electrical issue
Post by: jyeager on February 04, 2015, 03:31:35 PM
Where are you pulling the hot to run the fuel pump? Straight From the battery or jumped from somewhere else?


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Title: Re: Electrical issue
Post by: Bunger on February 04, 2015, 03:47:24 PM
Sounds like your alt isn't hooked up right. Should be about 13-14 volts when running. Is it a 1 or 3 wire?


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Title: Re: Electrical issue
Post by: Squirrel Master on February 04, 2015, 05:23:09 PM
Well I asked for a one wire but it does have the two prongs on the underneath side of the alternator and they just gave me a little rubber plug to cover it and said I didn't need to use those and I have the one wire from the alternator to the hot side of my battery
Title: Re: Electrical issue
Post by: Squirrel Master on February 04, 2015, 05:24:03 PM
Where are you pulling the hot to run the fuel pump? Straight From the battery or jumped from somewhere else?


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I believe I have it from the ignition to the switch to the fuel pump
Title: Re: Electrical issue
Post by: Chad89GT on February 04, 2015, 06:21:19 PM
As stated above, voltage should be right about 14 with the engine running.

Depending on your pulley setup it may take a few RPM to get the voltage up.  Try revving the engine to 2k and see if there's still no change. 

If it's still 12ish at 2k then get the alternator tested.  While testing make note if the guy hooks up the Field wire to excite the alternator.  Once you've ruled out the new alternator being DOA you can proceed with wiring.
Title: Re: Electrical issue
Post by: Squirrel Master on February 05, 2015, 02:01:39 PM
Ok so they gave me a three wire alternator cuz when I hooked everything up the way it should have been on a three wire diagram she's putting power back in her thanks boys
Title: Re: Electrical issue
Post by: Squirrel Master on February 05, 2015, 05:08:10 PM
Wait a minute I got one more question with the hot side of the prong to the hot that exit off of it to the battery it charges do you have to run the other wire  to resistor I don't have any kind of resistors in my boat so I just sent it to the power side that goes to the ignition and it works but I don't know if I'm going to burn s*** up that way or what
Title: Re: Electrical issue
Post by: Chad89GT on February 05, 2015, 05:13:53 PM
The field wire should have a switched 12v signal.  So long as the volt meter is reading around 14 you're golden.
Title: Re: Electrical issue
Post by: Squirrel Master on February 05, 2015, 07:10:49 PM
What do you mean switched 12 volt signal where does it need to go though because if I hook it up to anywhere that's getting power in it reads even if you unplug it it still reads at 14
Title: Re: Electrical issue
Post by: Chad89GT on February 05, 2015, 07:43:57 PM
You said 1 of the wires goes to the ignition switch, right?  That's the switched 12v. 

Resistors are typically only used on a points style ignition system, not the charging system.
Title: Re: Electrical issue
Post by: Squirrel Master on February 05, 2015, 09:22:50 PM
Ok ty
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