One wire Alternator

"I have a 1971 Trojan with a 3

"I have a 1971 Trojan with a 318. there was some discussion a while back about changing the two wire alternater to a one wire set up. My alt. has one bat wire and one smaller wire (I forgot where it goes). I also have a charging (field) relay and of course the voltage regulator. Is this a one wire set up? If not, how does the one wire setup go? Is the field relay still used? And what does the relay do? For $95.99, it ought to charge the batterys and wash and wax the boat."

"The only wire used on a one w

"The only wire used on a one wire alternator
is the fat red (usually) one going to the battery. All others are unnecessary.

Note: If you do extensive trolling, or very low speed running, do NOT go that way. The one wire alternators don't work at all until you boot the throttle, and tend to stop working below 1,000 rpms. Other than that they're super.

Jeff"

"In an auto, the small wire wo

"In an auto, the small wire would run back to the V. regulator.
i have no idea what the charging (field) relay does

Fred 156-M"

"The external regulator uses t

"The external regulator uses the field to control the alternator. In a one wire, it's all done internally.

Jeff"

one wire less mess

one wire less mess

"One wire , more cost ?? (

"One wire , more cost ?? (I don't know.)

Hey Russ, did you also buy a VCR / DVD combination unit to eliminate those "messy" wires between them?

Billy, is something broke?

I'm after inexpensive, & reliable.

Anonymous"

"Never gonna believe it... Reb

"Never gonna believe it... Rebuilt my 318 and installed it. Runs OK but wouldn't charge. My meter showed a slight discharge all the time. I traced wires and wiring diagrams, had the alternator tested, replaced the regulator... still no charge. So today I crawl in behind the instrument panel to chase wires again. I hooked up my lamp to a hot and ground lead on the fuses panel and just happened to bump a wire and my light went off. Bumped it again and my light came on. To make a long story short, the lead on the back of the ammeter was loose. I cleaned and tighten it and now I am charging perfectly. It really wasn't "loose" just not making connection. Never would have found it if the light hadn't gone out."

Think of the time and $$ that

Think of the time and $$ that loose connection cost you. Arrrgh! But it's fixed. Good work.

Jeff

"Jeff, This whole project has

"Jeff, This whole project has been that way. Rewarding in a most frustrating way!! She's painted, rebuilt and about to be renamed and resold. I plan on having a big renaming party. Instead on a BYOB its gonna be BYOGasoline tho!!
This is an F26 Trojan. At 23-2400 rpm she sounds and rides good. GPS says 17-18mph. At WOT, I only get 37-3800rpm (I still got carb/old fuel issues) gps shows 25-26mph. Does that sound close? Got any idea of fuel consumption at cruise? Or is this one of those cases where if you have to ask how much it is, you can't afford it?"

Fred I junked the vcr.....

Fred I junked the vcr.....

"Motor should burn about 7 to

"Motor should burn about 7 to 9 GPH at 2,500 rpm cruise, and about 2 gallons more per hour at 3,000.

Good luck!

Jeff"

RE: "wouldn't charge.

RE: "wouldn't charge. My meter showed a slight discharge all the time".

It probably was charging the whole time. On most boats there is a "shunt" and the meter on the dash is connected "across" the shunt and the meter just reads a portion of the current. The reason this is done is to avoid running a long wire to the dash for the live charge circuit. If this was done you would not be able to get enough current to flow due to the resistance of the wire to the helm and back unless you used VERY heavy (and expensive) wire.

"Robert, I agree. I never had

"Robert, I agree. I never had weak battery issues but it was one of those I needed fixed before I felt really comfortable being on the water for very long."

"In this initial thread I aske

"In this initial thread I asked about the charging relay (its actually called an alternator cutout relay)I had to find out what this cutout did because Friday morning my batteries were dead. What was worse was my voltage regulator was warm and had a constant 12v input even with the switch off. This relay has three terminals. One is a 12v constant input, 1 connects to the ignition switch and resistor and one goes to the alternator and voltage regualtor. When the ignition switch is turned on, it sends 12v to the relay which closes a set of contacts that then sends 12v to the regulator/alternator wire. The contacts in my relay stuck closed and sent 12v to the alternator and regulator even with the switch off. Thats what drained the baterries. Since I could not find one quickly, I took mine apart, separated the contacts, dressed them up and soldiered it all back together. Today it works like a charm. Tomorrow, I fully expect something else to go wrong.."

My darn Fiero used to do that

My darn Fiero used to do that sporadically. Never knew if the battery would be dead 'til I hit the key. Drove me nuts.

Let's hope you'll be all set from now on.

Jeff