Voltage Regulator trouble?

[orange72350]

I replaced my alternator yesterday, and my truck is still doing the same thing. When the rpm drop below 1000, the lights go dim and my turn signals blink really slowly. I redid the alternator wiring,(externally regulated) and retraced all my wiring, but i cant seem to find my voltage regulator. What does it look like, and where would it be? is this my prolbem, or does it sound like something else?
thax in advance
dale

[Gene]

Voltage regulator is on the drivers side on the inside of the radiator support beside the radiator and is usually a square box with rounded edges and I believe it has 4 wires going into it? I still am running mine with a voltage regulator but am planning on changing it to a internal regultated alternator if it ever goes out. Hope this helps.

[orange72350]

thanx.
does anybody have a pic of what the regulator looks like?
dale

[Gene]

Sorry I dont have a digital camera but it should be a small 3X3 black box bolted to the radiator support.

[orange72350]

perfect. thanx alot man.
are they cheap to replace?

[Gene]

I don't think they are real expensive, but I would still suggest going with a one wire internal regulated alternator.

[old Rusty C10]

regulators go for about $14.99-19.99 in the east here

[Longhorn Man]

I've seen them for 12 bucks, but this was about 5 years ago.
In reality, you'd be better off spending the 12 bucks at a junk yard and getting an used internally regulated alt. They really are ten times better, and they don't have the low charge rate at idle like the old crap does.
Anyways, here is the voltage regulator. It probably won't help your charging proplems to chainge it...but here is a pic of one. This shows the wires (if you keep your external set up...ignore the wire job on this) and the edge of the regulator. They are not always black, but they do seem to always be the same shape and size.

[Gene]

Are those jumpers you have to use if you use a one wire alternator?

[dinnut]

i have 2 of those on my 72... wtf???? if i have one of these does that mean my alternator is externally regulated?

[Longhorn Man]

You jump it like that if you use a stock later model internally regulated one.
There really is no reason to use a one wire unit. They have draw backs that most ppl don't bother talking about.

[lukecp]

I have a similiar problem with my truck. At a 650rpm idle in gear, if i turn the fan on the volt guage drops. With the fan and lights on the guage drops to about 10 volts. If my windshield wipers are on i have about 8 volts. I don't even want to think about tuning on the turn signial without turning off the heater fan.

When the truck is runing it can run all of those OK, except the volt guage drops to 12-13 volts or so. For some reason it never goes above 13, but i have it running off the same source as my HEI, tach, and CD player so that may be the problem, if it matters.

Will an internal regulated alternator give me more juice down low?

[barn9]

Internally regulated alternator is one of the easiest and best upgrades to these old trucks. A one-wire setup is a completely different change, and like Andy said, that method has its drawbacks. Once you eliminate that old voltage regulator, you'll be glad you did (and wonder why you waited so long to do it).
All you need is a newer style internally reg. alt, one jump wire for the plug off of the old volt. reg. (not sure why Andy has 2 on his), and the plug for the new int. reg. alt. (that will wire in to your original switched lead, and which should have a resistence diode built in to it). If your parts store doesn't have them, I can get them (I'm out of them at the moment). Easy changeover and well worth it.

[DanoDMano]

Name a drawback to a one wire alternator??????

I installed mine, it was a no brainer, and it works like a champ??
No jumpers on mine, but then I dont think my guage ever worked in the first place?

Inquiring minds want to know..

[Longhorn Man]

2 draw backs off the top of my head...
1. Getting parts when it goes out so you can get to work in the morning...or worse yet, home from your weekend road trip to the board meet.
2. depending on pully ratio, you have to goose the throttle to get a one wire to start charging. The one wire needs to have build enough inside to flash it before it'll start charging. That reving could be anywhere between 1100 RPM, up to 3600 RPM for an underdriven pully ratio set up. Neighbors don't like that when you are getting up in the morning to get to that car show on time, and if/when you loan out your rig, if they don't know/forget, they could never break the 1200 RPM charge spot, and drive it all over town on the battery. (sounds far fetched, but it happens)


My main thing is replacement parts. I want to be able to walk into any parts store, and walk out with part in hand. No matter what corner of the U.S of A you may be in, you can get an alt for a 77 C/10, and they will have it in stock.

As for the wireing I have there...I don't. That is someone else's. I re-engineared my entire harness when i had the motor out, and totally deleted the plug and the 15 feet of extra wire that was caused by that plug.

[DanoDMano]

Thanks Longhorn, now I see. Yeah I do have to rev it a bit, but it gives me an excuse to rumble in the morning....

As far as parts, I bought mine at the local Parts store and they keep them in stock!

[Gene]

I have an internal regulated alternator laying around, now i'm thinking of putting it on. Do you have a pic of your setup barn9?? Or do I do it like Andy's?

[BobbyK]

Another drawback to one wire alt.'s is no compensation for higher amp demands.

One wire puts out 14.2 volts all the time,no matter what the load on the electricall system is.The int. reg. maintains that 14.2 all the time.
So say the 1 wire is pumping out that 14.2 and you start turning on your accessories(heater,high beams,windshield wipers,and maybe that "pumpin" stereo with 1000wt amp.That's a heck of amp draw now.But as far as the 1wire alt is concerned all is good because it's still putting out that 14.2 volts.

The 3 wire or orig. GM system uses what's called remote sensing.It uses a wire(#2 terminal on the top of the alt.) to sense the voltage demand of the system and compensate for that demand by bumping up the output at the alt.

Again lets say we have all the stuff on like I mentioned above.The "sense" wire will see that all that load is dropping the voltage output of the alt. to less than 12 volts.The "sense" wire will then regulate the alt. by bumping up the output to maintain the votage needed to run all those accessories effectivly.

Does that make sense?

The GM system is much more suited for your daily driver.

I used to run a one wire with NO problems at all(2 years actually).But after looking on the net and doing some reading I've been convinced the GM,3 wire system is much better for your truck or car.

[PICKMUP]

I like these for simple instalation of an int reg alt. No wires to cut & splice, correct locking connectors for both the regulator harness and alternator. You just plug it in and go. If you are interested, just email me.

[Blue_71]

i wish i had of known about those plug in systems when i cut my harness

never ever hook up a external AND internal regulator... i did that for a while, made the battery boil and ruined a brand new Interstate battery

[barn9]

Here is the one I used and can get (the maker is here in Winfield).
The black stripe is actually the connector with the resistence diode. I used 1 jump wire on the old alt. plug with this and the new alt. The man that makes these has been making and selling them for 25 years now, no failures. It plugs in to the new alt., red wire hooks to ground lug on alt., and the white wire goes to the switched lead from the old reg. harness (other wires un-used).