





⚡ Power your drive with precision and pride!
The ACDelco Professional C603Z Voltage Regulator is a premium aftermarket replacement designed to provide precise voltage control, ensuring your vehicle’s electrical systems operate smoothly. Engineered for a perfect vehicle-specific fit, it offers superior radio noise suppression and reliable battery maintenance. Made in the USA, this regulator combines trusted craftsmanship with dependable performance to keep your engine and accessories running flawlessly.








| ASIN | B000C9QI96 |
| Best Sellers Rank | #244,898 in Automotive ( See Top 100 in Automotive ) #33 in Automotive Replacement Alternator Voltage Regulators |
| Brand | ACDelco |
| Customer Reviews | 4.4 4.4 out of 5 stars (251) |
| Date First Available | July 31, 2007 |
| Exterior | Painted |
| Item Weight | 5.6 ounces |
| Item model number | C603Z |
| Manufacturer | ACDelco |
| Manufacturer Part Number | 12336870 |
| Model | ACDelco - Voltage Regulat (B) (C603Z) |
| OEM Part Number | 12336870 |
| Product Dimensions | 4.7 x 2 x 4.1 inches |
C**S
Pretty decent
It works well enough. I'm using it to replace a broken regulator in the engine computer. With that in mind, the voltage does tend to fluctuate a decent amount with this regulator, especially under heavy load. The voltage gauge will actually wiggle back and forth when the turn signal is on. Otherwise, i've had no issues with this regualtor, you just have to make sure it has a really good ground on the case or you run a high risk of frying it.
M**N
Works well, Made in the USA!
I was searching the mopar forums for a reliable voltage regulator and most commented on the reliability of this particular item..( Bonus made in the USA)..and fairly priced as well!!
P**3
Will serve as my backup unit
If you have a Mopar, you’ll want a backup voltage regulator. At 1/3rd the price of the original equipment model, I chose this as a backup only because they are notorious for dying and leaving people stranded. When my original Mopar unit died, I bought two units; one Mopar branded one made in the US, and this one. I will only use this one as a “just in case” backup unit.
C**.
Fixed battery charging issue
It have been going for a month so far in the AZ summer heat. Only thing I noticed was this new VR was significantly lighter then the one I was replacing, and that usually means a cheaper build quality..
A**N
I GOT THE POWER!!!
I have an older dodge Dakota and thole alternator on those trucks are regulated by the pcm. Well I've done some modifications to the truck and It no longer has the stock pcm. I had to get one of these to be able to use the stock alternator on my truck and this worked great. No issues. Easy to wire up and thin enough to hide away
S**R
Avoid Avoid Avoid!!!!
Lasted 48 hrs, ended up putting the one back on from the 1980's and back to no issues. Avoid this garbage.
C**N
Worked as should
I bought for a late 80s dodge Minnie wine rv I bought and worked great but much else to say I ordered 5 more just as backups as I like to be prepared
M**Y
THE ONLY voltage regulator that should be sold!!
I put this in my 1987 Dodge D-250 after replacing the regulator just short of 2 years ago. I had bought some knock-off Jipp-O brand unit, and had nothing but troubles from the first minute!! First of all, that Jipp-O unit hada a real nice coat of gray paint on itt. Well that only served to insulate it from the firewall where its mounted, so I had to take out the grinder and grind off the paint at the 4 mounting holes... both sides. Then, the battery never charged fully. I'd hafta put the charger on it like every 2 weeks just sitting there. I had a parasitic draw on the battery, which I traced to THAT REGULATOR! I read in a Dodge Ram forum that a guy "ONLY uses AC Delco regulators... with no troubles." He said while they cost a bit more, ALL the others are utter GARBAGE! He was absolutely correct! As soon as I installed this one, I knew it was true, as my alternator belt would squeak when I revved up the motor (belt was too loose, but the other regulator never had the alternator work hard enough to make the belt slip!) Now I know... ONLY AC Delco for my trucks!!
F**E
Works perfectly
J**Z
Worked Perfect!
H**N
It's letting the alternator charge at 14.9v, a little higher then I would of liked but it works no issue
L**N
Fixed my electrical issues, and the sizing is EXACTLY the same as the original MOPAR model, so it was just a drop-in replacement. If you're installing this in place of the old chassis mount one, make sure that sand off the old mounts so you get a good connection! I totally gapped on this step and ended up having to run a new ground wire from the regulator to the battery.
P**R
Nock off in box
Trustpilot
2 weeks ago
2 weeks ago