alternator putting out too much volts

[donzi2]

After installing a new alternator on a 4.3 cobra noticed the volts output was more than normal 18v rather than the 12-14v. When in idle it's output is normal, but when underway at any speed too many volts.

Is it possible this alternator is for a car or is it simply a regulator defect thats attached to the back side of this alternator and needs to be replaced.

A bench test showed it works, but i think tere must be a load test that could have been done to show otherwise.

 

[f_inscreenname]

Re: alternator putting out too much volts

It's either a insane power drain or there is a issue with the regulator and/or install.
Also if it was a car Alt it would put out the same as a marine Alt but probably blow you up in the process.

 

[wire2]

Re: alternator putting out too much volts

Are you reading 18v on the dash voltmeter or a test style voltmeter?

If it really is 18v, I suspect the alternator is the type that needs an external regulator.

OR if someone had been playing with the wiring and it now has full battery volts to the field, output will be very high also.

 

[donzi2]

Re: alternator putting out too much volts

Dash & multimeter show the same volts. Took readings at alternator & and at the battery, both show 12v at idle and after revving for a minute it'll jump to 18v.

There is what looks like a regulator on the back side of the alternator.

Wirring not messed with. Old alternator packed it in, so bought this one from a alternator shop new out of the box.

 

[wire2]

Re: alternator putting out too much volts

Ok, how it's supposed to work is; the regulator senses battery volts on the red output lead/large stud. If it's high, the reg should cut back on the volts to the field, reducing the output.

How many connections/wires on the alternator?

 

[Benny1963]

Re: alternator putting out too much volts

prbaly voltage reg bad take it off and have tested
under load
b1963

 

[180shabah]

Re: alternator putting out too much volts

....so bought this one from a alternator shop new out of the box.

Take it back to the alternator shop, new back in the box.