The Stovebolt Site Forums The Shop Area The Electrical Bay What's on my voltage reg.?

Shortly after getting my truck, the old mechanical voltage reg. started chattering. As I was swapping out for new electronic reg., there was what looked like a condensor (resistor?) attached to old one and the wire was connected to terminal underneath which is part of #4 terminal. I didn't know what it was and the new reg. had the same extra terminal so I installed it same as old.
Anyone know what the heck this is? I can't find it in the manual or looking for parts.
The main reason I'm asking is I'm trying to fix an overcharging situation (18+ volts!) and expect I'll probably be changing the regulator again.
The #4 terminal is the wire that goes to the gauge so I'm guessing it's some sort of resistor?
-David

That thing is not necessary for operation. It's used to dampen radio noise. Maybe someone with a lot more electrical smarts than me will jump in here and explain the principles.

If it is a capacitor (condensor) it may have shorted out and may be causing your problem. Remove it before you blame the new regulator.

As laroke said, a condensor on #4 is for the radio.
If it was shorted, it would connect the alt "field connection" to ground through the regulator at all times and also the battery to ground when the ign key is on. The condensor is probably good.
You don't have 18 volts. If you did, all your light bulbs would be gone, the alt would be smoking, the bat would be cooked dry, the heater fan could clean out the inside of your truck and the cigarette lighter could cook lunch.
Take your voltmeter and compare it to another one. Or, lift the hood of some other car. One that runs good and has no electrical problems of any kind. A good battery, sitting in a car with nothing on and no drain, save for a clock, should read 12.5 volts. If your voltmeter reads 12.3-12.7 volts, then consider it good.
Now go back to your truck. Start it up, turn on the lights and check for bad grounds using the voltmeter. I said use the VOLTMETER. Do not use the ohmmeter. Do not look for bad grounds with your eyeballs.
That means that if you measure the voltage from the neg side of the battery to the frame, the voltage should be "0" volts. That means that if you measure the voltage from the neg side of the battery to the engine block, you should have "0"(zero) volts. That means that if you measure the voltage from the neg side of the battery to the distributor housing or alternator housing, you should have "0" volts. That means that if you measure the voltage from the neg side of the battery to the firewall and dash frame, you should have "0" volts.
By using the same idea, if you measure the voltage from the battery positive post to the starter solenoid large post, you should have "0" volts. If you measure the voltage from the battery positive post to the alternator "Bat" post, you should have "0" volts. If you measure the voltage from the battery positive post to the #3 post on the regulator, you should have "0" volts.
Voltage drops of a couple of tenths of a volt can be expected. Find the big drops and fix them first.

One other thing. The voltage reg has to be grounded. It sits on three rubber isolation pads for shock absortion and should have a short ground wire. If it's on the radiator core support, you need to check the voltage from the neg bat post to voltage reg and also from neg bat to the core support. The core support is the ground for the reg and also the headlights. The core support sits on two rubber donuts, is bolted to the fenders and they are bolted to the cab with some old rusty bolts and the cab sits on rubber pads. If the battery ground cable has an extra pig tail, then that is bolted to the core support, if that is where the bat is. What truck???

Thanks for the clarification on the condenser.
I tried to figure some things out today. I first checked the fluid level in battery. It's good. Next I installed a mechanical regulator that I borrowed from a friend. I cleaned the ground connection (a wire from horn relay mount bolt) at reg. and horn relay. Before starting, I checked battery voltage, it was 14.8. I started the truck and now had 17-17.5. Increasing throttle a bit got me over 19 volts. At this point I was thinking my multimeter was possibly (probably) reading high and also that perhaps the alternator I installed a couple months ago might be bad. Before doing anything else, I turned on the heater and all lights. That got me to about 14.8 volts at idle. With throttle increase I was back in the 18's.
Shut her off and yanked the alternator out of the '64 I just bought. Now, with lights and accessories turned on, I again had 14.8 but, when I increased throttle, voltage only increased to 15.2-15.5.
A funny thing happened on the way to work though. I have a power invertor in my glove box which is wired to my battery. It has a thermal protection built in, in case of over voltage or faults. Half way to work it crapped out. Don't know if this is just coincidence or what.
I'm gonna compare readings with a multimeter we have at work.
Richard, this is on my '65.
Appreciate the help.
-David

I compared readings with a multimeter (Fluke - the nice, expensive one) at work and mine reads about 2 volts high. Nonetheless, my voltage was high, going from 12+ up to 16+. The alternator appears to have fixed that.
Richard, I'll re-check grounds tomorrow.
Now, on to my next problem, the reoccurring random hard starts. Another post...
-David