Help! Electrical Problems (Alt?)

[Ratrace Remedy]

This all started when I replaced the spark plugs....

While reaching for the plugs on the port side, I knocked two wires off of the alternator. The wires are the small ones, the harness side is red w/purple stripe and purple. They were connected with butt connectors to red and green wires coming out of the alternator.

My manual is clear about the red w/purple stripe and purple, clearly describes where they go. The back of the alternator is not marked, so I don't know which wire from the harness goes to which wire coming out of the alternator.

The motor starts and runs great with these wires unhooked, but there's no charge indicated (checked with voltmeter, 12.74 at the battery when running, 12.84 at the battery when off). Also, I now have double the rpms shown on the tach, reads almost 2,000 rpms at idle - it appears to read actual engine rpm x2. Related?

Info, I haven't done my signature yet....
Boat: 1984 Formula
Engine: 350/260 merc
Alternator: Mando

 

[Ratrace Remedy]

Re: Help! Electrical Problems (Alt?)

UPDATE:

I decided to try it with the wires hooked in different combinations:

With both wires hooked up either way, no charge, engine runs fine.

With both wires unhooked engine runs fine, no charge (tested at the battery)

Te tach problem seems to have cured itself.

Is there a way to check the regulator by checking ohm readings from the wires?

I'm certain this is the original alt, so replacement may be in order. If I decide to go with a Delco 1 wire, which model number do I use?

 

[Coors]

Re: Help! Electrical Problems (Alt?)

I think you fried the diodes, with the short.

 

[Ratrace Remedy]

Re: Help! Electrical Problems (Alt?)

I think so too.

With the motor running I get 16v at the hot alt terminal (one with the orange wire).

It's off now, gonna take it around tomorrow to see about a replacement. Here's a pic of the back, you can see the two terminals I'm talking about, the small red and green wire. Also, looks like the regulator has been replaced before? (says Transpo).

If I go the swap route....where do I find info re: Delco one-wire alt swap? (part numbers, etc....)