Author Topic: 71 Cuda Voltage regulator question  (Read 3308 times)

Offline DocMel

  • Full Member
  • ***
  • Posts: 828
71 Cuda Voltage regulator question
« on: July 24, 2013 - 09:17:33 AM »
1971 Cuda, 440:  Just recently on a Sunday drive  (In the middle of the mountians with almost ZERO shoulder room to pull over). 

I was about 60 miles from home, when the engine started to sputter and got progressively worse until it died.   Battery was found to be about dead:  Selenoid clicks, thats it, so it wouldn't turn over.  I double checked all bat posts,  relay, etc while stuck on the side of the road.  On the spot I called it a charging issue, so i didnt want to jump start it and have die on the road again, especially when I was on an incline and on a  tight mountian road with virtually zero shoulder to pull over on 

No cell coverge, bottom line, I was able to get a tow to the local OReilleys. 

My bat was dead, so I got another on purpose to just limp home with, about 70 miles away, on another, flatter and wider  road : With a new battery, it started right up, ran great till I was almost home:  Same symptoms, sputtering till it died, but I did JUST barely make it home.  Def a charging system problem

At home, I checked every single related connection.  At firewall, at regulator, and at the back of the alternator:  All looked fine when removed

I recharged the new battery that night, and today it fired right up, ran fine to the local shop so I could  have the charging system analyzed:  Battery was good, hand analyzer said "low regulator output".  I also had the alternator checked out/bench tested:  Alternator  was good

So I went ahead and got a new voltage regulator:  Found out then, the old regulator was very loosley mounted on the firewall.  The mount bolts had basically just worn loose in the mount holes, and the regulator could def be wiggled around by hand

I installed the new regulator,  and put in larger bolts to ensure secure mounting and grounding of the regulator body

Question:  Does the regulator body need good and solid grounding to work properly and did the poor/loose mounting possibly cause my charging issue?




Offline JayBee

  • Resident
  • *****
  • Posts: 2477
Re: 71 Cuda Voltage regulator question
« Reply #1 on: July 24, 2013 - 09:39:35 AM »
I would say absolutely yes. I went so far on my car as to sand off paint were the VR meets the firewall, removed the leaf screen (for access) and put a nut on the back of the VR mounting bolts. It's never come loose and there's never been a charging problem.
John

1970 Barracuda convertible
2014 Toyota Avalon

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 71 Cuda Voltage regulator question
« Reply #2 on: July 24, 2013 - 10:20:12 AM »
 :iagree:
The reg has to be grounded well to work

Challenger - You`ll wish You Hadn`t

Offline 1970GranCoupeConvert

  • Jr. Member
  • **
  • Posts: 75
Re: 71 Cuda Voltage regulator question
« Reply #3 on: July 24, 2013 - 10:42:00 AM »
Was the Amp Meter showing a discharge while you were driving?

Now a days, with all of the new electronics installed in our cars (stereo, ignition system, electric fan, FI, etc) many guys have switched to the 13.5 continuous volt Voltage Regulator.  I did and have been very happy since.

There was some concern voiced (typed) on the other Mopar bulletin boards about it frying the battery however a bunch of guys replied and said that the ran one for years without any battery problems.  I figure that 1 additional volt is not going to harm the battery any and all of the components on my car are solid state anyway so I do not have any ignition points to burn out.  My new SUV has a Volt Meter on it and the volts never show less than 13.5 volts.  It even has a trailer mode that increases the volts to 14.5 volts when the trailer button is pushed.

Still with the new VR installed in my car and the engine is at idle with the lights on the Amp Meter will hover near the center position but will increase when the engine revs above idle...with the old VR installed the Amp Meter would dip slightly negative and the headlights would have a noticeable dimming at idle..
1970 Plymouth Barracuda Gran Coupe Convertible
First Car (purchased in October 1985)
Drove it throughout high school and early college (still do)
Full Frame off (K frame off) Rotisserie Restoration completed in 1991
Originally (and still is) a Rally Red, Black top with Charcoal/Silver Interior
340 CID with Holley Pro-Jection 4Di
LA 727 GearVendor  Overdrive
390:1 8 3/4 Rear end
Rally Rims (color matched)

Offline mopar jack

  • Full Member
  • ***
  • Posts: 566
Re: 71 Cuda Voltage regulator question
« Reply #4 on: July 24, 2013 - 11:04:49 AM »
70 Grand coupe, 13.5 volts is not really an extra volt. A 12 volt lead acid battery is actually 6 cells at 2.2 volts per cel which equals 13.2 volts when fully charged. Then the 13.5 adds a little extra to charge the battery.

Offline DocMel

  • Full Member
  • ***
  • Posts: 828
Re: 71 Cuda Voltage regulator question
« Reply #5 on: July 24, 2013 - 05:42:33 PM »
I dont trust the stock voltmeter:  It basically stays at the mid mark, and barley moves to the good when everything is working properly

Im considering a set of aftermarket gauges, (water, volts, oil pres) to mount under the dash  I have always had good luck with aftermarket gauges

Offline 1970GranCoupeConvert

  • Jr. Member
  • **
  • Posts: 75
Re: 71 Cuda Voltage regulator question
« Reply #6 on: July 29, 2013 - 10:50:03 PM »
>13.5 volts is not really an extra volt. A 12 volt lead acid battery is actually 6 cells at 2.2 volts per cel which equals 13.2 volts when fully charged. Then the 13.5 adds a little extra to charge the battery.

Thanks Mopar Jack!!!  This forum is great and I appreciate the pooling of knowledge.

When I installed mine I had some discussions and nobody could give me a definitive answer as to if the 13.5 Volt Voltage Regulator would cause any harm. 

All I know is that with my fuel injection system, the electric fuel pump, the heater running, the stereo and lights the ammeter would show discharge...now it is fine  and I have not cooked a battery so I am happy.  Your feedback provides the extra comfort for the long trips.

 :clapping: :clapping:
1970 Plymouth Barracuda Gran Coupe Convertible
First Car (purchased in October 1985)
Drove it throughout high school and early college (still do)
Full Frame off (K frame off) Rotisserie Restoration completed in 1991
Originally (and still is) a Rally Red, Black top with Charcoal/Silver Interior
340 CID with Holley Pro-Jection 4Di
LA 727 GearVendor  Overdrive
390:1 8 3/4 Rear end
Rally Rims (color matched)