Need help with voltage regulator - HU problem

[valterdaw]

My latest headunit is very sensitive to a voltage. On a cold start, my car produces around ~16v then in 20-30min it slowly drops to normal, which indicates voltage regulator problem (built-in in Bosch alternator). During this period of time headunit just shuts down it's display and disables all controls except volume and track change (Eclipse). I would rather avoid alternator replacement (lost receipt ), so I am looking at simple schematic of voltage regulator, which will be feeding just headunit. It doesn't need to be powerful, as I am using only pre-amp outputs from HU. I appreciate any help!

[ocaukrell]

Just politely, fix/replace the alternator.

Items that can be fried by high voltage.
Battery
headunit
amplifiers
ECU,s
bulbs
fuel pumps
fans
electric motors

So if you car is a later model that has fuel injection/elec windows etc.
You are asking for a world hurt.
Maybe not right now, but it will come back to bite you.

Last car I saw with a dead regulator needed, alternator, battery, car phone, ecu, gearbox controller.
End bill was around $5,000.

Your choice..............

[valterdaw]

Thanks! I am even not sure alternator (with regulator) will fix it, OEM and Bosch doing the same thing to my friend's simular cars. It's been like that for almost 5 years, it just went a bit higher lately with cold weather and battery replacement (optima, sealed). I might give it a try, pick up a different alt., which will be a good excuse to upgrade for bigger one

[ocaukrell]

Thats interesting.

I know the occasional system will generate/require high 14's, but 16, I'm thinking there has to be a fault.
Most alt will only put out 16 at maximum with reg failure.

What sort of car is it ??

[Jexx]

Stock alts are cheap, $150 max. Easy to uninstall/install for american cars...might want to check a junkyard.