Voltage Issues

[Nemos]

Ok, the wiring on my 1972 bay is a rats nest.

The engine is a 2.0 914, Altornator is a 70A from and newer Bay.

A while back the alt. light came on and the voltage would not climb past 12v

I have found the blue "trigger wire" for the voltage regulator that plugs into the alt. warning light on the dash. I also wound the same wire that goes to the brake warning light. when I plug the wire from the brake warning light to +12v everything works. But when i rev the engine my voltage climbs to 14.5 Volts. and when on the road for a little while I can see the voltage bounce back and forth slowly between 14 and 14.5 Volts slowly like a ticking clock.

My question... a silly one, is this bad ?

And whats the right wiring for the voltage reagulator ? where dose it get the signals and how do they work ?

Thx Guys.

[david58]

Ok, the wiring on my 1972 bay is a rats nest.

The engine is a 2.0 914, Altornator is a 70A from and newer Bay.

A while back the alt. light came on and the voltage would not climb past 12v

I have found the blue "trigger wire" for the voltage regulator that plugs into the alt. warning light on the dash. I also wound the same wire that goes to the brake warning light. when I plug the wire from the brake warning light to +12v everything works. But when i rev the engine my voltage climbs to 14.5 Volts. and when on the road for a little while I can see the voltage bounce back and forth slowly between 14 and 14.5 Volts slowly like a ticking clock.

My question... a silly one, is this bad ?

And whats the right wiring for the voltage reagulator ? where dose it get the signals and how do they work ?

Thx Guys.

The voltage regulator is regulating the voltage, it will be fine as long as it is a volt or two above battery voltage a small fluctuation is normal. All charging systems work off the supply and demand of the electrical system to maintain the battery. As long as it sees a positive charge adding voltage to the battery instead of a discharge taking away voltage from the battery and there isn't a parasitic draw on the system then you will be ok. Can you post a pic of the regulator so someone can help you with the wiring?

[wildthings]

Your regulator may be showing its age. The voltage should vary some with a mechanical regulator but it should be happening so fast you can not see the needle on your voltmeter move. If you are reading it with a digital meter you will get varying readings instead of an average like you would with an analog meter.

[rockerarm]

Nemos, The alternator in your bus, as well as other cars, is capable of putting out a lot more output than the battery will ever need. It is the job of the regulator to "sense" the battery state of charge and thus regulate back what is needed. That's the basics. Your blue wire, as it is commonly called, the exciter wire, supplies 12v to the alternator but since this 12v has flowed thru the dash bulb, it has no amperage to it. Without this 12v exciter you have no alternator output. It has been a while, but I think this blue wire does go to the brake warning lite on the dash. My concern, which should be yours, is that as old as these cars are now, I personnaly would suspect the brake warning lite to not being funtionable anymore (we dealer/independent techs had issues with this switch 20-25 years ago) and I like the KISS principle (keep it simple soldier). What I would assure is that the 12v, blue, exciter wire has nothing else in its circuit. Especially if the wiring is a as you said "rats nest". In closing, I also believe what wildthing stated in his response as I do not think a .5v variation is worth chasing. Bill