Hi all. Searched but didn't find anything on this...

My 'vert was acting weird today, so I looked down and noticed the voltmeter was (almost?) pegged at 16+ volts.

I turned on the headlights and fan and got it down to normal, then drove straight home, but something is very wrong.

I'm thinking alternator (AGAIN!), but both the alternator and battery are virtually new, (as well as the starter.)

I do have a ridiculous aftermarket sound system and HID headlights that seem to tax the electrical, but can anyone clue me in to what causes such an over-voltage condition?

Thanks for any insights in advance...

 

That would be a voltage regulator problem (in the alternator). There should be a test in the FSM you can perform, or an auto parts store can bench test it.

 

Thanks...

I figured there must be a voltage regulator in there somewhere, and assumed it was going to be IN the alternator.

I'm clearly overtaxing the alternator, and have yet to figure what higher output model is affordable and fits...

In the meantime, will check the FSM.

 

Make sure the two wire, small plug is connected to the ALT.

Key ON......engine OFF.........pull the small plug off the alt and see if there is batt voltage on both wires in the small plug.

IF that's so......reconnect the small plug and backprobe the White/Black wire in that plug. Should read approx 3vdc with the plug connected to the alt and key ON engine off.

See how that goes for you. Your alt is not regulating as mentioned before. The White/Black NEEDS to be connected to the alt and should show the 3vdc I mentioned above.

 

Thanks for the diagnostic technique. Plug was connected, was getting c. 3VDC on white/black.

Alt. got real HOT with engine running for 1 minute. Pulled Alt.

FOUND the receipt for the alt. (WOO-HOO!) Less than 3 months old.

Free swap for another at MacKenzie Auto Parts right nearby home, (they rock, everything IN STOCK.) Salesman asked if my battery started to boil. (!) It didn't (but I didn't let it, kept voltage down with fan/lights on till I got home.)

New alternator is in, works great!

But I'm sure I'll somehow manage to fry this one too soon as well...

RX7 Club rules.

Mackenzie Parts Warehouse in SF: http://mackenziewarehouse.com/

 

It's your system i remember putting subs into my vert and tree days later my alt was dead.

 

Yes, I blame the sound system for overtaxing the alternator.

I do have a large capacitor for the amps, but I believe I'm supposed to add a 2nd battery to make things more sympatico...

 

Hello,

had the same problem a while back, alternator was charging with 15,5 V on medium load.
Overcharging can damage the ECU and other components, PO didnt know about the
alt overcharging, so I took care of it after purchase

Got a new alt and battery, now everything is fine. I would like to have a battery with
more capacity but it works the way it is now.
Thrown lots of money into the car since I have it.

Steven

PS: seems like a competent part store you found there.
*Thinking bout our part store over here charging 100$ for 1 BUR7EQP* lol