Argo conquest Denso alternator, too high voltage

[Midtveit]

Hi
My 1996 conquest with Kawasaki engine are suddenly showing high voltate at high RPM. And the voltage meter needle is peaking above 14 volts and vibrating, the water temperature needle is also vibrating. Hence my thinking is that somehow the alternator is giving to high voltage and unstable voltage since voltage meter needle and temperature needle is vibrating like crazy.

I suspect the alternator regulator or rectifier bridge (Diodes).
Maybe just as well to by new alternator ?
Or could it be the regulator, there is one box thing right side of the "dashboard" below the voltage meter.

What I am also puzzled with are that the alternator says regulator inside, if there is a regulator there why is there an external regulator.
Conquest Denso alternator.jpg

[Midtveit]

OK, I realize I need a new alternator. the argo one seem quite expensive compared to other aftermarket. Has anyone tryed any aftermarket alternators ?

[dirtdobber]

Midtviet, allow me to make a suggestion. Before you jump into buying a new alternator, remove yours and take it a place like AutoZone and see if they can test it. It must be charging since your voltage is spiking and perhaps they can determine if the internal regulator (if it has one) has failed. You may be able to repair it.

[Midtveit]

Thanks for advice :-)

[needcoffee]

Might be worth checking it with a volt meter in place just to confirm the voltage. Concerning replacement. Any nippon denso will work. Just make sure to swap out the pulley.

[AlaskaGrizzly]

I was able to locate the Denso part number and purchased a new Denso for a lot less then the Argo price in the past. Also had a friend buy a "knockoff" brand that matched up to the Denso part number hand had good luck with it, and it was something like $50 with free shipping on ebay.

The voltage regulator you have on your dash is for the motor stator power output. Typically I'd expect that it would have been unplugged when the accessory add on Denso was installed.

[Midtveit]

Thanks no I understand, that means i can removet then right?

[needcoffee]

Here is the Denso # 18504-6220 I installed might be the same one you need. Mine is a 2 wire so the key power provides excitation current. Mine was an add on to a 2015 Frontier so is not a factory offering.

Whether the vehicle onboard voltmeter is measuring stator or alternator output is a valid concern. You should verify it is disconnected from the stator and connected to your fuse block or distribution bus where it will measure alternator output.

[AlaskaGrizzly]

Yes if your engine power supply is still good you can remove the accessory alternator.

[Midtveit]

Well, the conclusion to my troubles are that both the original charging and regulator and the add on alternator with built in regulator was active.
Why the voltage was unstable all of a sudden I dont know, my only possible explanation was a worn out fan belt on the added alternator.

But I took out the alternator, got it tested and it worked well in test bench. Back to the argo I replaced the alternator fan belt, disconnected the old charging regulator, and result was dead stable charging voltage much better than it ever where before.

My only worry now is that my batter has been overcharged for 5 years and is probably a bit tired.