[C38] Alternator and charging
Tom T.
tdtron at earthlink.net
Mon Jun 29 18:27:35 EDT 2009
Hello Steve,
You are correct. The 30 amp fuse in your charging circuit is too small to carry the load if the batteries are discharged or you are running other high load applications. I expect they may be using a small fuse to try to reduce the maximum load on the wiring harness which has been a problem in the past.
To carry a high amperage load to your engine control panel is not only a lot of electrical loss but it can be dangerous if your harness connections are corroded. There have been many original engine control harnesses burned up because of the high load on the amp meter wires in that harness.
The amp meter isn't needed anyway. You can have an amp meter showing a lot of amps but if your battery bank is shorted, you will only be creating heat on the harness and load on your engine but a shorted battery will never charge with the amp meter giving you a false sense of security. A volt meter gives a better idea of your charging and battery conditions.
A more practical solution to the amp meter is to replace the original amp meter with a marine grade volt meter. To do this, you run the output of the alternator directly to your battery banks and use the original wires to the amp meter to feed a new volt meter. You can run the feed to the volt meter from the positive side of the starter solenoid since it is very close to the alternator making a very easy conversion.
The volt meter conversion is a very good and highly recommended upgrade. It will make your boat safer and your alternator will perform better because more output will go to the battery bank instead of wasted in heat loss in the harness and possible faulty connectors.
Fuse the wire that you run from the solenoid to the new volt meter. There will be very little current on that wire now so even a small fuse like 5 amps will do fine. The fuse should be very close to the alternator for safety.
It has been a long time since I made this modification on my boat but I believe the harness wire used for the volt meter conversion is an orange wire. I wrote an article for Mainsheet several years ago about this conversion but I don't remember what year or month it was but I'm sure I can find a draft copy in my archives if you need it, just let me know and I'll look for it.
Good luck,
Tom Troncalli
Renata (Hull #95)
----- Original Message -----
From: Steve Smolinske
To: Catalina 38 Listserve
Sent: 6/29/2009 4:35:25 PM
Subject: [C38] Alternator and charging
Tom T, I'm hoping you can add some insight on this. I suspected my system wasn't charging so I took the alternator and starter off and had them both tested, they are fine, and since there off I took the precaution to have the regulator, brushes and contacts replaced. Going over the wiring diagram for the M30 They call out #10 wire with a 30 amp fuse inline from the amp meter to the Starter Solenoid. Knowing that a regulator varies charge based on battery condition/charge and rpm isn't a 30 amp fuse undersized, and why a fuse anyway, shouldn't the wire be sized correctly to handle the highest load the system would see.
Steve Smolinske
President
4M Company, Inc.
15660 Nelson Place South
Seattle, WA 98188
425-227-4500
www.rainierrubber.com
The information contained in this email may be confidential and/or proprietary in nature and is intended for the recipient of the email only. Please treat all information contained in this and any communication with the 4M Company as such. Thank you.
P Before printing, think about ENVIRONMENTAL responsibility
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://catalina38.org/pipermail/listserve_catalina38.org/attachments/20090629/c157c753/attachment-0001.htm>
More information about the Listserve
mailing list