ConcoursMustang Forums

Restoring - General discussions that span across many different groups of years and models => Misc Items => Topic started by: orlandod on February 26, 2020, 04:19:52 PM

Title: Fluctuating Alternator Gauge
Post by: orlandod on February 26, 2020, 04:19:52 PM
Electronics is a another one of my hobbies and even I am getting frustrated by whats going on. I started a partial restoration of the dash since I needed to take out the AC/heater box due to cracking. Repainted the lower dash with red oxide on the back and black on the front. The gauge needles were painted, new printed circuit sheet, LED gauge bulbs and lenses, new 5v regulator, new voltage regulator in the engine bay along with a new battery, new ground wire from firewall to block, same alternator but I removed the harness and and cleaned up the connectors and reinstalled. I even went as far to install a secondary ground from the lower dash to the car body and still the Alternator gauge is bouncing around and when it does the foot well lights fluctuate. I stopped into three auto parts stores and they all said the alternator is good..... suggestions would be appreciated.
As I am driving it will settle down but then start up again???
FYI... before starting the project the gauge was rock solid to the point where I thought it was non functional.
Title: Re: Fluctuating Alternator Gauge
Post by: 1967 eight barrel on February 26, 2020, 04:53:55 PM
I had a similar issue with my Shelby with the needle bouncing all over the place. It turned out to be a regulator. I went solid-state. I used the reproduction Concours cover and a Dremel drum sanding bit to shape the resin so the cover would fit.  It's pretty much rock solid again.

                                                                  -Keith 
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 26, 2020, 05:59:26 PM
I just installed a AMK C8TF-Autolite thinking the old one was bad. Is this new one not solid state electronics???
Title: Re: Fluctuating Alternator Gauge
Post by: cobrajet_carl on February 26, 2020, 06:02:55 PM
What does it do if the engine is off and you turn on the headlights on hi beam?
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 26, 2020, 06:07:11 PM
Just went out to the garage and the gauge moves slightly to the discharge side of the dial so that tells me it knows what is going on and reporting properly.
Title: Re: Fluctuating Alternator Gauge
Post by: 1967 eight barrel on February 26, 2020, 06:24:48 PM
No, the AMK units are not solid-state. I had my AMK stater solenoid weld the contacts, as well as the regulator points, burn.  When you have the turn signal in operation, step on the brakes or turn the headlights on it should slightly fluctuate to the discharge side.  Because of the Shelby having six 1157 bulbs burning it was much more apparent until I went to the plasma LED lamps. Much less draw now.
                                                                                                     -Keith
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 26, 2020, 06:35:14 PM
I have replaces all the bulbs in the car to LED (excluding headlights), front and back turn, interior, gauges, glove, sifter, radio, backup, trunk, side markers. The left side seems to have more difficulty when it comes to turn signals. The left turn rate will actually slow down to the point of stopping when I am at a light. When I reduce the load by putting the car in neutral or if I release the brakes when the is green the indicators start up again.
Title: Re: Fluctuating Alternator Gauge
Post by: 1967 eight barrel on February 26, 2020, 06:44:36 PM
I am running all LED as well but the headlamps and the front running lamp/turn signal bulbs. It's nice to be able to see the instruments at night now.  I have decided to run the plug and play relays for the headlamps from Rocketman. He primarily caters to the cougar community.  The halogen lamps are substantially brighter because they pull power via the battery, not through the harness. They require no modification and for those of us who actually drive our cars, they are night and day difference.
Bob is a great guy and will always take the time to explain anything that is in question.
                                                                                                         -Keith


https://www.rccinnovations.com/index.php?show=menu-mustang-all
Title: Re: Fluctuating Alternator Gauge
Post by: cobrajet_carl on February 26, 2020, 08:17:36 PM
Just went out to the garage and the gauge moves slightly to the discharge side of the dial so that tells me it knows what is going on and reporting properly.
Really sounds like the regulator.
Title: Re: Fluctuating Alternator Gauge
Post by: midlife on February 26, 2020, 09:32:52 PM
Really sounds like the regulator.
+1. 
If you're not going true concours, you can get a solid-state version.  Some folks take the concours cover and swap it onto the solid-state with some success. 
Title: Re: Fluctuating Alternator Gauge
Post by: Bob Gaines on February 26, 2020, 10:39:59 PM
+1. 
If you're not going true concours, you can get a solid-state version.  Some folks take the concours cover and swap it onto the solid-state with some success.
The reproduction assemblyline ones Virginia sells are solid state.
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 27, 2020, 08:58:35 AM
I honestly thought I was buying a solid state regulator from AMK but as "1967 eight barrel" commented that is not the case. I guess the next thing to do is spend another $25 to eliminate the regulator from the equation. I am looking for an inexpensive one and came across this at Napa...... comments

https://www.napaonline.com/en/p/MPEVR440SB?partTypeName=Voltage+Regulator&keywordInput=voltage+regulator

If this does not solve the problem I guess the alternator will need to be looked at next.
Title: Re: Fluctuating Alternator Gauge
Post by: RoyceP on February 27, 2020, 09:10:11 AM
This might help:

https://www.428cobrajet.org/forum/index.php?topic=11197.msg66393#msg66393


I honestly thought I was buying a solid state regulator from AMK but as "1967 eight barrel" commented that is not the case. I guess the next thing to do is spend another $25 to eliminate the regulator from the equation. I am looking for an inexpensive one and came across this at Napa...... comments

https://www.napaonline.com/en/p/MPEVR440SB?partTypeName=Voltage+Regulator&keywordInput=voltage+regulator

If this does not solve the problem I guess the alternator will need to be looked at next.
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 27, 2020, 11:55:22 AM
Solved...... partially. I went out to Napa and picked up voltage regulator VR440SB and that solved the fluctuating alternator gauge and flickering lights.

The next annoying thing is that the turn signals slow down and even stop after sitting at the light for a while. I am wondering if it is cheap electronic flashes I installed to go with all the LED lamps I was putting in the car. Are there better quality units out there?
Title: Re: Fluctuating Alternator Gauge
Post by: carlite65 on February 27, 2020, 12:41:40 PM
"cheap electronic flashes"..............therein lies your answer.
Title: Re: Fluctuating Alternator Gauge
Post by: 1967 eight barrel on February 27, 2020, 07:03:08 PM
I think you just figured out your own problem.....  Scott Drake make one and there is a pot internally that allows you to "time" them.
I went through Vic at Cougars Unlimited for my electronics. I wired sequentials into my Shelby. I hate the Dynamite sticks and others that sequence when the brake lights are in operation or the hazards lamps.
You have to be blind to miss the brake and turn signals with the plasma leds.
                                                                                                                 -Keith
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 28, 2020, 10:49:42 AM
Thanks for the info. I will look into an adjustable flasher
Title: Re: Fluctuating Alternator Gauge
Post by: Texas Swede on February 29, 2020, 10:31:05 AM
The charging lamp was flickering in my 65 GT350 and I found the problem to be the combination between a
rebuilt alternator (60 amp) and the AMK regulator which was built according to the original spec. which is calibrated
for a much lower alternator amp. Bought a solid state regulator and added the AMK cover and no flickering any more
and it still looks original.
Texas Swede
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 29, 2020, 02:14:11 PM
After installing the Napa $25 solid state regulator I decided to open the $50 AMK unit from Classic Automotive and contrary to what "1967 eight barrel" stated above the unit I received is solid state so I am not sure what when wrong with it but I will be swapping over covers very soon.
Title: Re: Fluctuating Alternator Gauge
Post by: 1967 eight barrel on February 29, 2020, 04:22:50 PM
The unit I threw in the trash was in fact mechanical. Wasn't a guess or hearsay.   Perhaps AMK has decided to change manufacturers and move away from the original design because so many of us here have had issues with AMK's Starter solenoids welding the contacts and the regulators failing/intermittent operation.  A bad or loose grounded unit or loose battery cables will quickly destroy solid-state electronics. NAPA offered three different units. I opted for the more expensive unit NAPA offered and the electronics are encapsulated in resin which had to be shaped a bit to get the reproduction cover on. Be sure that there is bare metal where the unit touches the core support and there is also an external star washer used between the unit and the regulator. It's also shown clearly in the Jim Osborne assembly manual. 
                                                                                    -Keith
Title: Re: Fluctuating Alternator Gauge
Post by: orlandod on February 29, 2020, 04:35:30 PM
I not disagreeing just surprised to see electronics in the unit. Your comment about a loose ground got me to thinking because when I removed the AMK unit one of the mounting screws was loose which may have destroyed the unit. I went ahead a ground off the paint around the screw holes for the new install. Your comment about the star washer is a good on and I will pick some up. Thanks