alternator conversion

[ollie947]

hello. i have a 1978 mark twain 898. can the orginal 3 wire alternator be changed too the one wire style. i was running my boat for about a hour, turned it off then like 10 min later i went too start it and ...... so yeah.. the battery is new and was charged. i just dont want too pay the 200+ for a orginal one. id much rather have the one wire style since its cheaper.

 

[Silvertip]

Re: alternator conversion

Have you actually diagnosed the problem as the alternator or are you just guessing?

 

[ollie947]

Re: alternator conversion

i havent tested the alternator yet. but..... can the 3 wire be converted too the single wire?

 

[bashr52]

Re: alternator conversion

Chances are the 3 wire alternator is externally regulated. A one wire style would be internally regualted. In order to make the switch you would simply just need to bypass the regulator. I've done it on older cars many times.

If that is the case:
Trace your wiring back from your alternator and find the regualtor (should be a little box with some wires going into it and one big wire comming out and going to the battery). Depending on the type of one wire alternator you are looking at, some really take 2. One is a smaller one and one is the main one to the battery. The small one gets wired into a key switch to "excite" the alternator field when the key is on, the other goes directly to the battery. True one-wire alternators only have one post which goes directly to the battery and serves to both excite the field and charge the battery. If it is a true one wire, simply remove the heavy lead from the regualtor, and wire it directly from the alternator to the battery. Make sure to remove all the old wiring you are no longer using.

 

[Boatist]

Re: alternator conversion

First you should run some test to see what the problem is.
Check your battery voltage before starting the engine, it should be about 12.6 volts. Then start the engine and check the battery voltage again, it should now be 13.8 volts or higher.

If it is the Alternator then the next step is to see what caused it to go bad. I believe turning the battery switch to off with the motor running causes most failures. Also turning the battery switch at all with the motor running if it is not a make before break style switch.

I like a 3 wire alternator better than a 1 wire alternator but any can be converted.