Voltage Regulator ?

[cliffsta]

Ok, got the alternator rewound, its in, truck is running. BUT the volts fall off just as bad as before!!!

Now the guy rewound it and converted it to one-wire, BUT we plugged up the "second" wires, too. Now if I'm not mistaken, those extra wires go to the external regulator, and a "one-wire" alternator has an internal regulator. Is my external regulator bad, causing me to lose volts? Should I just unplug the extra wires, the ones I don't "need"?

I'm really frustrated with this electrical crap.

Thanks so much for the help.

[Lynx]

The 2 wire plug IS the voltage regulator. They are internaly regulated.
The large wire is for Battery +
One of the conector plugs is for the Dash light or voltmeter
The other conector plugs is an exciter or activator for the internal regulator.

Not exactly sure how the 1 wire works but basicly it elimiates the plug and gets those 2 signals either internaly or externaly.

I'm pretty sure thats how it goes but if Ive screwed up some one correct me.

That being said, im not exactly sure what your problem is. Was the alternator bench tested before you got it back? Genearly when its rebuilt they would check your regulator, drio, rectifiyer bridge, and all that jazz. Is your battery good? You didnt at any time run the engine with the alternator belt on but no wires hooked up did you?

[cliffsta]

I'm pretty sure he said he bench tested it that it works.

He didn't touch anything on the truck, as a matter of fact I had to take it out at my house, bring it to the shop, he worked on it, my dad picked it up on his way home, so nothing has been touched on the truck.

No, it has not been run with any wires disconnected.

The battery... that has been my next guess but before I jumped off and bought one...

Me and the old man looked at the battery when we put the alternator back in, it looked pretty $hitty inside, as in, could go any day. It's way past the warranty for sure. We topped it off with water. Could a bad/old battery cause me to not maintain volts?

Basically what the problem is, just like BEFORE i had the alternator redone... sitting at stoplights or idling, the volts fall off if I have accessories running (A/C, stereo, headlights)... today in traffic I just had on A/C and the stereo (mind you, just a head unit and two 6x9s) and the volts fell to the red in the gauge at every stoplight.

So, having explained all that, you still think it's the battery?

Thanx for the quick reply Lynx.

I'm in a "thanks" mood tonight LOL

[boxrodz]

Are you sure you have a one-wire alternator? If so, then you only have one wire coming from the battery to the alternator as Lynx mentioned. If you still have one wire of the plug going into the alterator then you have the two-wire setup. Under this setup, the alternator is triggered by the ignition wire. If you do have a true one-wire setup, then you're need to rev the engine slightly to trigger the alternator. My guess is that you probably have the two-wire setup. The tech 'bably just eliminated the 'voltage sensing' wire. Maybe, double check your wiring to be sure that the ignition wire is connected to the alternator and not the voltage sensing wire. What's your voltage when the engine is idling under no load (no accesssories turned on)? What's the voltage when you turn on the electrical component?.

BTW, make sure the alternator belt has the proper tension. Although a loose belt will normally squeal when slipping. If it is slipping, you will notice a voltage drop when the electrical components are turned on especially when the engine is idling.

I wouldn't think it's your battery unless it's not holding a charge. You can usually have it checked out for no charge. And, if the regulator went south, then you 'bably would notice a fluctuation in voltage as the engine revs change.

[Slonaker]

Swervin has an article on 73-87.com about wiring up a one wire alternator. Maybe read it, and boxrodz's post, to figure out what you have and what to do with it.

Slonaker

[cliffsta]

Everything's plugged up like it came from the factory despite the guy saying we didn't have to have it all plugged in.

My next step is to unplug the wires he told us were not neccessary.

The more accessories I turn on the worse it gets, even it its just the radio and headlights. Turning on the A/C compressor just completely kills the voltage day/night radio/no radio.

I am sure the crappy ancient battery isn't helping too.

SO does that cover everything you've suggested? I haven't checked the belt tension but I can do that too tomorrow.

My present guess is that the external regulator is bad or somewhere in that wiring there is a leak (is leak the right word?) and I am thinking of disconnecting the wires he said we didn't need plugged in.

Thanks for the help, keep the knowledge flowing, y'all just might learn me a thing or two.

[cliffsta]

ttt

c'mon i'm desperate, do i gotta hit myself with a hammer and make a video to coax info?

I checked belt tension, that's good.

It happens independant of throttle position.. like i was going down the road with a/c and radio this afternoon and it was below 13 v

I'm putting my amp and stuff in tomorrow, but its gonna be worthless if I can't run it

[Lynx]

Get your battery tested and if its good take the alternator back.

[boxrodz]

Originally Posted by cliffsta

ttt

c'mon i'm desperate, do i gotta hit myself with a hammer and make a video to coax info?

I checked belt tension, that's good.

It happens independant of throttle position.. like i was going down the road with a/c and radio this afternoon and it was below 13 v

I'm putting my amp and stuff in tomorrow, but its gonna be worthless if I can't run it

Well, skinning your knuckle while turning a wrench would help or touching a plug wire with the engine running or ... (Sorry, I'm video impaired... )

With the truck idling, the alternator should be putting out around 14 volts regulated (13.5 - 16 volts). The voltage level shouldn't change with the accessories turned on. If you're getting less than 13 volts (say 12 volts) with the truck running, then you're probably just running off the battery alone. If so, I would think that after a while you would notice slow-cranking when starting the truck. The battery would drain unless the battery itself cannot hold a charge. (Have it checked for insurance.) If the regulator is not internal to the alternator, then check the external regulator. I would think that with the alternator running, you should be able to measure the voltage reaching the regulator (coming from the alternator). You should also be able to get a voltage reading on the output side of the regulator (going to the battery). (It's been a while since I've seen external regulators.)

I'm not sure a voltage leak would cause your problem. A constant voltage leak would probably just drain your battery. If the tech bench tested the alternator successfully, it sounds like you may have an open in your wiring. With a stock alternator, if the wire going to the sensing terminal is faulty (open), then the alternator isn't turning on, by design. If the tech wired it to turn on with the ignition (field) terminal swiching the alternator on, make sure the wiring is not faulty. With the wiring terminal harness plugged into the alternator and the ignition switched on (engine not running), check the voltage reading between the BAT terminal on the regulator and GRND, and between each of the terminals under the wiring harness and GRND. You should observe non-zero readings between each of the terminals and GRND, if the wiring is good.

That said, maybe changing the wiring to your alternator like the tech suggests might solve your problem (but, I'm not quite sure how?).

Good luck.

BTW, did you figure out what type of alternator you ended up with?

[cliffsta]

based on what you said its a one-wire, b/c the red+black wires he said we didn't need. We hooked them up anyways, I guess we shouldn't have done that?

The votls stay right at 13 give or take when its idling in park, but in gear idling the volts fall to ~10

We've got the amp and extra speakers in, it really pulls the power when I've got it turned up...

Where would be a likely "open" in my wiring?

Tomorrow I'm unplugging those wires I don't apparently need, maybe that is my problem. Next step is to take it to Auto-Zone to test the battery.

Thnx so much for the help all.

[boxrodz]

Well, if you have a one-wire alternator, then you can ignore the wires leading to the terminal harness since the only wire used is the larger battery wire (from the BAT terminal of the alternator to the battery). Typically, an one-wire alternator is has a special regulator that that senses a certain minimum RPM before activating the alternator. You'll have to bring up the RPM a bit to get the alternator to turn on. That's the downside of one-wires. You gotta keep the RPMs above a certain threshold to maintain the ~13.5 volt output. Take the truck out and slightly rev'ed the engine (in gear) to see if the alternator 'turns on'. (It sounds like it's turning on when you have the engine idling in PARK.) It should drop down again, once the engine RPMs drop, like at a stop light. The only wire to check would be the wire between the alternator and the battery.