Amp Gauge is Bouncing

[Ed]

My amp gauge used to stay a little to the positive side when all the lights were on. And it would be right in the middle when the lights were off. Recently the gauge has started to bounce back and forth really fast, almost looks like it's vibrating. The lights are also fluctuating, they go bright then dim, bright then dim. Today with the lights off the gauge was all the way to the right, almost touching the +60 side. It stayed there for about 5 minutes then went back to the middle and started bouncing again. Is it my voltage regulator? As far as I can tell it's as old as the car.

[AxtellZ]

i am NOT an electrical guy, nor have i had this problem, but i would *guess* it is the VR going bad. Seems i have read/heard these symptoms together. What i do remember is the rule of three- that is the Battery, Voltage Regulator, and alternator will tend to all die together, especially if you let one of them go to long. Hope someone else can tell you more, Good luck! JA

[Daniel]

The other item to check.The volt reg. has a plastic connector that mates with the wiring harness.The white wire turns the volt reg on and off.The connection on the harness side goes bad.If you have never had a volt reg a new one wouldn't hurt.I hate to just throw money a problem, but knowing its 30 years old if not todays problem it will probably be tomorrows.I would get that fixed fast.An overcharged battery can leak acid killing the metal it hits,the fumes will eat the paint from under your hood,it can explode. Daniel

[jcdozier]

I strongly suggest you take Daniel's advice and fix it fast.

One of my sons (the mechanically-challenged one) learned to pay attention to the ammeter the hard way - blew the side of the battery out. We had a major clean-up job, with LOTS of baking soda to neutralize the battery acid.

Even if your battery doesn't leak, or worse, explode, overcharging causes the electrolyte to boil. That isn't condusive to long battery life.

[Ed]

Whoa! So if I were to tell you that my battery does leak then I guess it would all be related?

[Daniel]

Yes it overcharged and boiled.My thought s are it is the wire I mentioned or the volt reg.The battery is no good now.Wear safety glasses,better yet a face shield and cover your skin,wear gloves and get the battery out.Batteries can be real dangerous when they have been abused!! Daniel

[Dan]

Hey Ed if you need a new VR quick or anyother parts right away go and see Lee at All Z Wrecking. As the name suggests it's a wrecking yard that deals only with Z's, it is the Valhalla of Z parts.

Infact i have a couple of VR's myself if you need one. I live in Mission Valley let me know if i can help.

[Ed]

Hey Dan, Thanks for the offer but I ordered a new

VR from Motorsports. I hope to get it Monday. I have done business with Lee at All Z before. What a great place! I got my rims from Lee.

So my battery is no good anymore? How come?

[Daniel]

Perhaps we should have said your battery is now of questionable dependability.Once you boil it, you are on borrowed time.It still has the potiental for other problems as well.Its a rather safe than sorry deal. Daniel

[Ed]

Well, it took me a while to get it all together but I believe it's all working fine now. I put in a new VR from MSA. And a new OPTIMA SpiralCell battery. The amp gauge actually looks like it's working. It stays in the center when at idle. With the lights on and all accesories the guage moves slowly to the positive side. It doesnt't seem that the lights go dim when I'm at idle. The real test will be tomorrow night when I go to work. I'll let you know.

[visionary]

Over the last 10 months I have driven my '73 back and forth to Denver from Boise five times (900 miles each way) and had some problems with the charging system.

A couple of things happened that might help you. On one trip the alternator diodes welded together causing the system to overcharge and boil my battery. I had the alternator rebuilt by the best electrical shop I could find in Denver and it has been no problem since ($100). It gives a positive reading of about 5 amps normally now. The ramifications were that I had to replace the battery, the VR and rewire at the harness because it damaged the connector and burned up wiring. So, check all of those areas as they are vulnerable to damage when overcharging occurs.

On a return trip, somewhere in Wyoming, I started to get needle bounce on the meter and pulled over to look the system over. What I found was a wire at the harness connector had vibrated loose and had an intermitent connection and signal. After securing the wire it eliminated the "bounce".

Good Luck

Keith

[reintr0ducing]

HOLY 6 YEAR OLD THREAD BATMAN! i searched for amp gauge and found this, so i decided to bump this instead of starting a new thread...

i have the bouncy amp gauge problem and when i'm revving/accelerating, the needle steadily creeps up to the +60 side. i just changed the voltage regulator, but i boiled the battery and have just been charging it on my charger.

so what do i need to do? new battery and double check my connections? faulty VR?