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help with fluctuating amp gauge
https://www.slantsix.org/forum/viewtopic.php?t=13529		 Page 1 of 1
Author:  DART68 [ Thu Jun 30, 2005 6:38 pm ]
Post subject:  help with fluctuating amp gauge
I started my car after clocking out from work as usual. I turned my heater on to help it warm up faster and the power started to surge high then low a few minutes later. So I turn off the heater and the gauge is straight up and down, I hit the gas and the needle starts jerking half way to charge and back to straight up until I take my foot off the gas. It then stays straight up while at idle. When I turn on my turn signal the gauge swings slightly to discharge in sinc with the turn signal. Long story short, every time I hit the gas the needle jerks from straight up to half way to charge, back and forth until I stop accelerating. What is the likely problem? I'm thinking alternator or voltage regulator. I'm hoping that I don't have to worry about a potential melt down.

Thanks-Dart68
Author:  SlantSixDan [ Thu Jun 30, 2005 6:42 pm ]
Post subject: 
Voltage regulator is faulty. Replace it in a hurry. Run a ground wire from the new regulator's base to the "GRD" hole on the alternator's rear housing.

(Ummmm...it's June/July and you're in Los Angeles. You turned on the heater?? How come? What do you mean "help it warm up faster"?)
Author:  DART68 [ Thu Jun 30, 2005 8:07 pm ]
Post subject: 
The heater warm up trick I've been told is that the heater helps heat up the coolant along with the engine combustion cycle. I forgot to metion that I upgraded to 2 field alternator and later VR. Thanks for the info SlantSixDan. I think I have a spare laying aroud.

Thanks-Dart68
Author:  Craig [ Thu Jun 30, 2005 8:12 pm ]
Post subject: 
I've had loose connector to that electronic voltage regulator cause problems. I had to squeeze the connectors through the rubber to make them fit tighter. Pull the connector off and look inside to see if the things are spread open.

You may also have worn out brushes in the alternator.
Author:  SlantSixDan [ Thu Jun 30, 2005 8:31 pm ]
Post subject: 
Quote:
The heater warm up trick I've been told is that the heater helps heat up the coolant along with the engine combustion cycle.
Um...no. Not even close to being correct. The heater is nothing more than another radiator. Engine coolant circulates through the heater core (analogous to the radiator) while the fan or the forward motion of the car forces air through the coolant-heated core. This heats the air.

Turning on the heater does not in any way help the engine warm up, or warm up faster. In fact, it slows down the engine warmup, by taking heat out of the coolant and thus defeating the thermostat's blockoff of the radiator during warmup. Whoever told you this was either grossly misinformed or having a joke at your expense.
Author:  DART68 [ Thu Jun 30, 2005 9:02 pm ]
Post subject: 
Now that I think about it, you are absolutely right. I've read where guys have stated that they turned the heater on in their vehicles to avoid over heating in some cases. Makes perfect sense. I also had one of my manuals near bye and realized that there is no kind of electrical heating element of any kind in the heater box. Thanks for opening my eyes. I don't recall seeing a ground location on the back of the alternator but I'll check. If I do find it do I just run the wire from it to one of the two mounting screws for the VR?

Thanks-Dart68
Author:  DART68 [ Thu Jun 30, 2005 10:29 pm ]
Post subject: 
Well, it wasn't the VR. I'm going to try replacing the alternator now and see what happens.

Dart68
Author:  DART68 [ Thu Jun 30, 2005 11:54 pm ]
Post subject: 
It was my alternator! Luckly for me I had a freshly rebuilt one that I found in a junked Fifth Avenue 2 years ago. My car even seems to idle better or am I feeding too much into fixing the problem. In any case "YEAH".

Thanks-Dart68
Author:  SlantSixDan [ Fri Jul 01, 2005 9:50 am ]
Post subject: 
Quote:
I don't recall seeing a ground location on the back of the alternator but I'll check. If I do find it do I just run the wire from it to one of the two mounting screws for the VR?
Yep!
Author:  70Challi [ Sat Jul 02, 2005 10:32 am ]
Post subject: 
:P Boy am I glad I cruised through this forum! This post just opened my eyes very wide. My son and I just purchased a 1970 Challenger with a slant 6 for a family project. When we first drove the car home the original engine spun a bearing and I thought we might throw a small V8 in it. But Noooooo..... My son suggested we be different and replace the engine with another Slant 6!

Gawd, I love this kid! Dare to be different! To make a long story short after the engine was replaced I noticed the amp gauge was constantly flickering, especially while at idle but smoothed out under load. I'm an old school Ford and Chevy man and I know absolutly nothing about MOPARs s and their different(?) wireing system.

After reading this post I ran out to the garage and made a ground wire. I hooked it to the alternator and when I went to connect it to the VR hold down screw the VR almost feel off the firewall. I cleaned up the firewall mounting location. Cleaned the back side of the VR and hooked up the ground wire to new hold down oversized screws and fired it up. NO MORE DANCING AMP NEEDLE........ :lol:

It appears I have a new home and I hope to learn a lot more, as well as contribute to the forum. Once again thanks for this great forum.
Author:  64ragtop [ Sat Jul 02, 2005 11:55 am ]
Post subject: 
Dart68 wrote:
Quote:
I don't recall seeing a ground location on the back of the alternator but I'll check. If I do find it do I just run the wire from it to one of the two mounting screws for the VR?

Thanks-Dart68
and Dan replied "Yep" (in his usual somewhat laconic style and mincing few words)

In my much wordier style, now, I ask: The ground wire from the VR to the Alternator just assures a good ground for the VR, which is not assured by the VR mounting screws, huh??? :?
Author:  DART68 [ Sat Jul 02, 2005 2:06 pm ]
Post subject: 
Okay, my newer two field alternator only has a battery post and the two field posts. SlantSixDan, where would you reccomend connecting the ground wire to?

Thanks-Dart68
Author:  SlantSixDan [ Sat Jul 02, 2005 6:22 pm ]
Post subject: 
The ground connection isn't a post or a terminal -- it's an empty small round hole in the back of the alternator housing. Sometimes it's tucked in between two fins and tough to see, but it's there. And yes, the wire just assures a signal-quality ground between the alternator and the voltage regulator. This wire often cures/prevents slow voltage regulation resulting from noisy ground. Slow voltage regulation results in flickery lights. Very annoying.
Author:  69a100 [ Tue Jul 05, 2005 9:27 am ]
Post subject:  VR Wiring
You can also get info by going over to Moparts.com and look in the archives as they have pics and stuff about this topic.
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