Alternator

[Turbobus]

New 100 amp alternator from quality power, new voltage regulator, complete new wiring harness, the problem is that in drive, 700 rpm, the needle is showing discharge, voltage is 11.2 volts, bring up the rpm to 1000, 13.9 v and needle is in the middle but in park or neutral the rpm is 1200 rpm way to high in my opinion. Is there something I can do to increase the performance of my charging system at idle? Before the restoration the needle was rock steady, charging right after starting then settled down to the center and you could put in drive, fan on, brake lights on etc. and still steady in the center.

 

[diesel_lv]

Smaller pulley on the alternator.

 

[Dave6T4]

Try putting your old voltage regulator back on and see what happens. If it was controlling voltage better with lower amp alternator, it is likely a better piece than your new one. Have you upgraded your charging system wires to 8 ga. with upgrade of your alternator to likely double of stock output?

 

[dadsbee]

I'd be figuring out why you're dropping 500 RPM in drive first...

 

[68 Sport Satellite]

your voltage readings are pretty precise. Not a stock gauge I assume? What gauge are you using?
I had something similar happen when I installed a 70A Powermaster alternator. Two things - check your pulley belt tension. Second thing is even my 70A alternator is higher than stock output and didn't work with my original voltage regulator. I know you installed a new voltage regulator, BUT I didn't discover mine was a problem until I fried my temp gauge. I switched to a voltage regulator with adjustable potentiometer on the back (make sure proper grounding of VR case to firewall by sanding off paint near bolt hole) and checked battery voltage at idle and adjusted the VR until it was 13.8-14.1 at idle and now all is good. Your voltages are a little low instead of high, but possibly your system could benefit from this adjustable style as well.

HD External Adjustable Voltage Regulator Chrysler Dodge Plymouth, 1970-87 | eBay

 

[68 Sport Satellite]

I'd be figuring out why you're dropping 500 RPM in drive first...

probably dropping that rpm due to inadequate voltage.

 

[Turbobus]

Smaller pulley on the alternator.

I think it’s the smallest one available but I will certainly check it out, thanks

 

[Turbobus]

Try putting your old voltage regulator back on and see what happens. If it was controlling voltage better with lower amp alternator, it is likely a better piece than your new one. Have you upgraded your charging system wires to 8 ga. with upgrade of your alternator to likely double of stock output?

Didn’t you read the first part of my post where I said I was an idiot! Maybe I forgot to mention it! I tossed my regulator, for reasons unknown, lesson learned! Great thought though, thanks!

 

[Turbobus]

Try putting your old voltage regulator back on and see what happens. If it was controlling voltage better with lower amp alternator, it is likely a better piece than your new one. Have you upgraded your charging system wires to 8 ga. with upgrade of your alternator to likely double of stock output?

Oh, and yes, I might need to increase the wire size, good point.

 

[Turbobus]

I'd be figuring out why you're dropping 500 RPM in drive

Smaller pulley on the alternator.

good point, not happy with my cam or converter choice, it’s been very difficult to get it to idle the way I like, gotta pull engine anyway due to an external cracked block, yay!

 

[Turbobus]

your voltage readings are pretty precise. Not a stock gauge I assume? What gauge are you using?
I had something similar happen when I installed a 70A Powermaster alternator. Two things - check your pulley belt tension. Second thing is even my 70A alternator is higher than stock output and didn't work with my original voltage regulator. I know you installed a new voltage regulator, BUT I didn't discover mine was a problem until I fried my temp gauge. I switched to a voltage regulator with adjustable potentiometer on the back (make sure proper grounding of VR case to firewall by sanding off paint near bolt hole) and checked battery voltage at idle and adjusted the VR until it was 13.8-14.1 at idle and now all is good. Your voltages are a little low instead of high, but possibly your system could benefit from this adjustable style as well.

HD External Adjustable Voltage Regulator Chrysler Dodge Plymouth, 1970-87 | eBay

Yeah, that’s the first thing I did and I thought I was on to something, fresh paint, new regulator,,,,, possibly a not so good ground, unfortunately that didn’t cure it, but hey, great minds think alike!
I will however order one of those adjustable regulators just to rule it out, thanks!

 

[Nacho-RT74]

Try putting your old voltage regulator back on and see what happens. If it was controlling voltage better with lower amp alternator, it is likely a better piece than your new one. Have you upgraded your charging system wires to 8 ga. with upgrade of your alternator to likely double of stock output?

He is doubling the alt output CAPACITY but not necessarily the output. If the car load requirement sucks 35 or 45 amps to work, you can install a 500 amps alt but the car will still require the same 35 or 45 amps to work... So the alt will provide JUST that while voltage is also stable.

the bigger alt capacity on this case helps on get the best output posible at the slower rpms and save the batt from being discharged when alt is not capable. So this would/should guarantee a batt always charged what doesn’t mean CHARGING status…and the ammeter on zero reading, except for some minutes after crank the engine where should be recharging the load lost when sourcing the starter motor.

sure this happens while everything is in order.

I’m wondering about a bad diode on alt?

 

[Nacho-RT74]

Smaller pulley on the alternator.

I thought on that possibility, but… I think aftermarket high output alts come already with the smaller one. I just have seen rebuilt to stock alts getting the big ones

 

[Dave6T4]

Does anyone make an adjustable electronic voltage regulator in the older '62-'69 style? For single field alternator.

 

[Darter6]

Check your service manual, The point type 62-69 are adjustable.

 

[Dave6T4]

You missed the word "Electronic". My electronic ignition upgrade does not like the old points style regulator, because of "spikey" voltage. I also converted to an electronic regulator that looks like the original square box style. I wondered if anyone had an adjustable version of this?

 

[Darter6]

OOPS !! Sorry about that.That's what I get for reading too fast.Old style case I doubt it.Yes there are adjustable electronic Mopar VR's on E Bay.
New style case and plug.
Mopar Action did a article about them a few months ago.

 

[zyzzyx]

These are all the reasons that I went with a Denso alternator on my 440. Internally regulated, and
charges at idle. The original design wasn't sufficient to charge at idle.

 

[Turbobus]

These are all the reasons that I went with a Denso alternator on my 440. Internally regulated, and
charges at idle. The original design wasn't sufficient to charge at idle. View attachment 1354601

No light dimming, discharging at idle?
What kind of mods were required. Where did you get it? Thanks for your input!

 

[64fury74charger]

I went through some wasted time and money trying to smooth out the original system and the so-called new parts are really iffy at best. I put on a power master 100 amp internal regulated alternator and substantially upgraded the charging wire and eliminated the bulk head connector as well.

So far everything works well and voltage doesn’t drop below about 14.2 volts at idle with everything turned on including the blower on hi. Just my opinion and experience and that’s all.