Posted on 03/12/2008 6:04:20 PM PDT by djf
Question for car enthusiasts:
I put a new starter and battery in the Impala. After I did it, the internal lights and dash lights, etc were flickering. To make a long story short, I replaced the alternator.
Bit the voltage at the battery was nominal... so I tried to adjust the voltage regulator.
The car has the original Delco-Remy voltage regulator in it. It consists of two coils, one is called the field effect coil, and one is the voltage regulator coil. There is a timy plastic button that adjusts the gap for the voltage regulator coil.
With the gap closed, the voltage at the battery is nominal. With the gap wide open, the voltage is high (about 15.5) I seem to get the best results if the gap is adjusted so there is sparking in between it.
So my question is this: assuming I'm right, that the gap should be set kinda in between open and closed, should I do that:
When all the lights are on, the blower motors, the wipers, I mean at what is about full load, or when the lights are off and drainage is at a minimum
Also, mechanical voltage regulators like this are notoriously susceptible to temp changes, so should I do the adjustments when the car is at operating temp? Or is cold good enough?
I know if I turn the button all the way out so that it's always open, the voltage keeps climbing and goes up to about 17 and I don't want to kill another battery.
Thanks!
paging Click and Clack!
I would install a sprinkler system under the hood so it puts out the fire.
Thanks! Some of us geezers are still good for something!
I know I could tell you how to build a beautiful dual layer aluminum metal heat shield for a Chevy starter!
The voltage will be high without a voltage drop across the load. leave it high.
You don’t think a constant 15-17 is too much for the battery? I had a voltage reg give out on a different chevy and it blew the battery caps off because it was putting out 19V
15-16 could be considered nominal. It is in my T-Bird. Your 19 sounds very high under load.
Put the regulator back where it was and find the bad ground you created.
OK!
Well, like I said, the 19 was on and old Blazer I had that I replaced the alternator on. That one went back to the shop.
So I will back it off and set it high, but leave it close and assume it’s in there to protect from voltage spikes.
And find that crappy ground that is barely making it.
Ground Connections should be checked for corrosion in all areas from the battery to the block to the alternator to the starter. Somebody isn’t happy and there is too much resistance.
I know what you’re both saying, and I doubled checked that. After putting in and taking out the alternator a couple times, it wasn’t doing the flickering stuff, but I was still getting no action at the battery above what it would read turned off disconnected stone cold.
I had the alternator out and cleaned and reset all the brushes and contacts. But I was still wondering about where the voltage reg should be set, because I’m tired of putting the charger on it.
Can you check resistance on your battery cables? Maybe they are old...
We’ll if it’s a matter of that, maybe the rectifier diode is shorted on the alternator and has a direct path from the battery to ground.
Alternator was in the shop today and tested.
All diodes are good.
Low voltage 13.70 Actual voltage 14.68 high voltage 15.7
So the alt is good, it’d just a question of getting the reg set right because it doesn’t surprise me that it’s acting a little quirky after all the stuff I’ve replaced.
You have a bad path somewhere in this circuit possibly even back to your switch. I don’t think I can help on-line. Good luck. (Check those coils good).
Well like I said the flickering is no longer a problem. As I turn the button on the VR, it goes from having zero effect at the battery to taking it up to about 17 volts.
I’m just wondering about optimal workings under load and temp, etc.
I still don’t have a clue what the field effect coil does.
Bypass the voltage regulator and upgrade to a 12si or CS130-type alternator.
Compared to either of those, the old 60s alts look like the end result of redneck engineering. External v-regs SUCK!!!!
I could keep replacing parts and pretty soon I’d have like a Toyota or something!
What can I say? This stuff was before Bill Gates invented Plug N Play!
The 12si and CS-series alternators were both produced by GM for their then-new products and are offered as retrofits by many, including GM themselves.
The 12si should be a direct bolt-in swap once you bypass the old fire-prone regulator. The CS130 takes a bit more work. You can also swap in the CS144 and get 140-350 amps to play with.
FYI, my hobby is building/modernizing old Jaguars, which often either had GM pieces from the factory, or can accept them. Unless you’re going for a trailer queen, there is no reason not to update the electrics and mechanicals.
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