Deperate for some Alt. Wiring Help

I had posted this problem last year and thought I had it fixed. I have 1999 Supra Santera that I think has some sort of grounding problem. Temp gauge would spike making me think I was overheating added a secondary ground to that gauge directly to the battery kind of a band aid but problem solved. The next problem which I feel is part of the same problem is the fact that if I turn on two many accessories i.e. running lights, blower, bilge at the same time the boat dies. I mean dead no electrical power of any kind. It's like someone just yanked the battery out of the boat. After about 15-20 minutes every comes back boat fires up like nothing happened. I asked skidim.com and they said in the past they have seen grounding problems on Supras with the alternator. I remember the guy I bought the boat from saying he recently replaced the alt. So my question for you guys is can someone either say the way it's wired right or point me in a direction of some sort of wiring diagram. I have attached the best pics I could get. The only part number I could pull off of the alt. was 8RG2043 which is for the regulator I think which is Leece brand. The first pic shows the factory wiring harness with the black, orange and purple wires. The purple is not connected to anything (doesn't seem right?). It also shows the thick black wire that is mounted to the regulator and then goes around the front of the alt. and is then screwed in with a alt. mounting bolt.




The next pic shows where the factory orange wire is mounted to the alt/regulator




The last pics show the yellow, black, white, and green(this ones seems to be snipped off) coming out of the regulator and then being tied into the alt.




Boat runs perfect besides the dying thing which last year I just learned not to turn on to many things at the same time. Seems like the problem should be pretty easy to fix though. Any help or advice would be greatly appreciated.

there may be something on this site that will help you. http://www.outboardrepairs.com/wiring/

Otherwise talk to an alternator repair guy. He may have some ideas for you.

Sounds as if you alternator may not be pumpin out any juice.

(Message edited by BCRider on May 02, 2008)

First check the main ground, should be some place on the engine block. Seems like you have at least looked over the wiring at the alt itself, look for bad crimps on wires, corroded terminals, etc. Then check your pos and grnd wires that head up to the dash etc.

We had some weird issues with an alternator on an older nautique, the voltage would suddenly spike and the main breaker would pop. Was most likely something to do with the voltage regulator on the alternator. Put in new alt and all is well.

Question though, with the boat off, can you crank up all your accessories?? Or does it shot down??

If it's only a condition that exists with the boat running and the alternator going, then that should be your cause. Sounds like something is heating up inside the alternator and causing an electrical problem.

Just some thoughts, I am no expert or mechanic. But I do try and fix my own stuff and have dealt with similar issues. I would just replace the alternator, it's 9 years old anyway if it's original equipment.

Dave, alternator pumps juice fine. Batteries stay charge.

Flux I haven't tried turning everything on with the boat not running to see if it does it. Good idea. Thanks.

J., your alternator is a Leece-Neville. Going off your regulator number you have a 110-567, 110-603 or 110-602. If the lower mounting foot is 2 inches you have a 110-602. If it is 1" it is one of the other 2. The 603 is a 90 amp and the 567 is a 105 amp. I am trying to find out some more information from my shop guy but here is a link to a diagram of the back of the alternator.

http://prestolite.com/images_alts/dimdraw/pdf_web/8MR2069TA_rear.pdf

Brett thanks for your help so far. I really appreciate the time you put into it. Do you know if that alt. is shown with a regulator on it?

yep. That is how I looked it up. Here is a link to a list of all the L/N marine alternators like yours. It has a list of the alternators on them.

http://prestolite.com/literature/alts/PP1128_marine.pdf

J., after talking to my shop guy we don't think it has anything to do with your alternator rather your ground circuit. I would find the main ground bus bar that is connected to the negative terminal of the battery. Make sure the connections are all tight and clean. It is a good idea to check all the connections while your doing it(battery ground/positive, starter ground/pos, and alternator ground/pos). Even if your alternator dies you will continue to run and the systems will work until the the battery is dead. I am guessing but somewhere your ground circuit is bad which is creating more resistance. This causes added amperage and heat which is then blowing an automatic circuit breaker. Once the circuit breaker cools down it resets.

Thanks again for your advice so far will follow the ground circuit then and check connections. I thought it might have to do with the grounding of the alternator or something since that was what was replaced before I purchased the boat. Did your guy have any idea what the hell that purple wire is supposed to do? Seems like it should be connected to something right? Also I wonder where this automatic circuit breaker heats blows then cools back down would be.

It may have been for an external regulator on the original alternator. Just remember that your charging, starting, battery system is like a big circle. Anywhere you break it or there is additional resistance can cause problems for everything else.

I see I thought that was an external regulator

If somebody might be able to tell me where the main ground wire from there battery is grounded to I would appreciate it. Mine is ground to the transmission and wanted to make sure that was where it was supposed to be. All the wire this guy messed up before me I wouldn't be surprised if it was. I guess I also need some help spelling, just checked the title.