Alternator to weak for my Charger?

[andben]

Hi guys, got a BIG problem with my Charger '69. When crusing (which I do like 90% of all time in capital Stockholm due to traffic jams) my battery runs out of powha! When checking it does not charge the battery on idling. I need 1800 rpm to get to like 13.00v. I got some kind of stock alternator and yesterday I bought a 135AMP cable and put in on battery + and the alternator. No success. Still not charging when idle. 

Should I buy a Powermaster 140AMP (or similliar) and skip the AMP-meter inside car? (dont need that anyway). Like a "one-wire"-alternator? 

Please advice, everyday I take the battery out of the car and charge it in my apartment :/ 

[Cooter]

http://www.jegs.com/p/JEGS/JEGS-1-Wire-GM-Alternators/750748/10002/-1

[myk]

I'm not a fan of stock equipment/technology on old cars, but before you start buying parts and throwing them at the car, try and find out why the car isn't charging properly.  Even the crappy stock charging system with the 30-60 amp (?) alternators should keep your battery charged under all operating conditions (idling, cruising, lights on, brake lights on, high beams on, radio on, air/heater on, ALL OF THE ABOVE, etc).  If you just go ahead and buy a higher 'amp alternator you might still have a non-charging issue...

[mhinders]

I fully agree with you MYK.
Normally the stock alternator is more than capable of keeping the battery charged during most conditions. There is something wrong with your alternator, regulator, wiring or grounding.

[andben]

Thx, Guess I need to do some investigation.
I got electric fans x 2 (big ones), electronic fuel pump and electronic fuel injection, pretty nice CD.. The alternator shows 14.6xv. Battery when idle shows 12.40v. Over 2000 rpm it show 13.30v. When I touch the breaks (breaks light on doh!) it drops dramatically. 

No problem when I really drives the car over 30-40 mph but cruising 1-2 hours (constantly breaking lights), cat wont start and I need help 

[andben]

http://www.jegs.com/p/JEGS/JEGS-1-Wire-GM-Alternators/750748/10002/-1

If I put GM stuff in my Mopar my friends wont talk to me anymore.. dont wanna risk that!

[John_Kunkel]

The later Denso alternator will work with your existing regulator, they commonly come in 90 and 120 amp versions. It should take care of your accessories.

[ACUDANUT]

There was a article in Mopar Muscle many years ago that showed this upgrade.  You have to ditch the points.  It works great on my 70.  I wish I could find it and copy and paste it.  I am sure someone here can show you how it's done.

[myk]

'OP, you don't have to go GM or 'Jap brand on your car if you don't want to, although I can only guess that the alternators being used today no matter what brand or make are probably made overseas anyway, lol.  Here's a thread that gives a lot of good ideas and  guidelines when trying to install a higher output alternator.  Personally, I took a 90 amp alternator from an early 90's Dodge van and went that route: http://www.dodgecharger.com/forum/index.php/topic,19802.0.html

Lol, with electric fans and all that other stuff you listed your stock alternator doesn't stand a chance.  All I have is an MSD box and my car ran better with the higher output 'alt...

[ACUDANUT]

I stand behind Chrysler's electronic ignition.  Only had one box fail me, out of 6 cars.  Wiring is so simple you will laugh.
MSD= Multiple sad disappointments. 

[Cooter]

http://www.jegs.com/p/JEGS/JEGS-1-Wire-GM-Alternators/750748/10002/-1

If I put GM stuff in my Mopar my friends wont talk to me anymore.. dont wanna risk that!

Then you REALLY don't wanna know who made the Police/Heavy Duty alt for Chrysler then....

[mhinders]

Thx, Guess I need to do some investigation.
I got electric fans x 2 (big ones), electronic fuel pump and electronic fuel injection, pretty nice CD.. The alternator shows 14.6xv. Battery when idle shows 12.40v. Over 2000 rpm it show 13.30v. When I touch the breaks (breaks light on doh!) it drops dramatically. 

No problem when I really drives the car over 30-40 mph but cruising 1-2 hours (constantly breaking lights), cat wont start and I need help 

Ok, I surrender...with all that stuff running your original alternator isn't up to the task anymore...

[myk]

I stand behind Chrysler's electronic ignition.  Only had one box fail me, out of 6 cars.  Wiring is so simple you will laugh.
MSD= Multiple sad disappointments. 

Lol, I've had nothing but success with the MSD box.  Although if you really wanna laugh about something get this:  I was so clueless about wiring that I had BOTH the MSD box and the orange ECU box connected at the same time!  No wonder my stock 'alt couldn't keep up...

[BrianShaughnessy]

Aside from a larger alternator to run all the electric fans and whatnot...  you should look into upgrading your wiring before your car goes poof.

Specifically,   you need a larger main feed cable from the alternator output back to the main load center.     You should also ditch the ammeter as you're using way too much current for it to handle and it'll probably either blow or catch fire sooner or later. 

Old cop car wiring used a shunt around the ammeter... that's one way.   There are other ways like having the ammeter converted to a voltmeter. 

[andben]

All my wiring is brand new... but I dont know anything about wiring to the amp-meter. Gotta check that up before loading it with 140AMP

[mhinders]

All my wiring is brand new... but I dont know anything about wiring to the amp-meter. Gotta check that up before loading it with 140AMP

I'm not sure new wiring is any guarantee for a safe function in your case. I'm assuming the electrical system has been modified with relays for the cooling fans etc. and it's not easy to say where the main current is flowing today, most of it probably already bypassing the ammeter...

Myself I would start with assuming worst case, everything is running, fans, injection, head lights, brake lights, stereo, battery charging...and add up all the Watt-numbers that you have. Once you know the total amount of Watts, you can calculate the worst case current by using the formula current=Watts/Voltage. You know Watts and voltage and you get the current in Amperes.
Once you know the Amperes you can start sizing the wires...from available tables. Then you need to figure out which wires are involved in the big currents and make sure they are safe both with fuses and in wire size...not that easy actually unless the supposed modifications are documented...
Just my thinking...

[Nacho-RT74]

andben

maybe you are probably on same deal than me in Caracas with the heavy traffic on city.

what I did is to use a lates 70s Mopar amp. They are able to put around 45-48 amps iddling and 78-85 reving up. Iddiling is the most important value to your car since in transit will be the most time will be working. These alts as stock replacements can be found at the web between $45 to $60

its a cheap solution and easier being plug and play. Just need to get longer alt belts since these alts are a little bit wider and the rear of alt could meet the block on rear

These alts, being dual field wired, and 69 being single field alt, will require just ground one of the fields to make it work on your system.

also an advice, get a upgraded electronic regulator. These regulators are same look and wiring as your old mechanical unit, BUT electronically upgraded inside.

you can also upgrade to the stock Mopar electronic system what will match the alt I'm recomending without any kind of field grounding and will require get the propper regulator, run an extra wire between reg and alt and splice into the system the regulator plug.

68neverlate who is from Canada, found a canadian source able to built stock alts able to source even to 100-120 amps if you want as max output ( that makes around 60 amps iddling wich is ideal specially for AC cars ), but they a little bit pricey, at least to me. Is a GREAT solution though. He did it on his car

any amps upgrade you make, will require some other upgrades on wiring, and CHECK EVERYTHING on charging system ( terminals, plug, ammeter conditions etc.. )

read this:

http://www.dodgecharger.com/forum/index.php/topic,33574.0.html

that will help you on understand how it works the charging system on our cars

[mhinders]

andben

maybe you are probably on same deal than me in Caracas with the heavy traffic on city.

Hey Nacho, I'm sure Andben will update you with the current traffic situation in Stockholm...but when I lived there 10 years ago the traffic was bad in the outskirts of the city in the mornings and evenings, but I can't imagine it being anywhere like the traffic in Caracas 
Besides, you probably have 20C hotter air temp all summer time...20C in Stockholm and 40C in Caracas...

I was looking at the link you pointed to, very nice drawings and good work!

Not sure it was mentioned but the regulator can also contribute to low alternator output at idle. The current from the regulator flowing through the field winding is magnetizing the rotor, and the amount of magnetism is corresponding to a certain output from the alternator. There is a physical limit for the amount of magnetism, and if the regulator sets it at max at idle revs, it cannot do more and the alternator cannot output more. The only alternative then is a bigger capacity alternator. Just to say that having an intelligent regulator is also very important for the output at idle revs.

Cheers,
Martin

[andben]

Thx guys! And thanks for that URL... reading with passion! 

[b5blue]

Mancini Racing's 120 amp Denso upgrade kit will solve all this. I've got a topic with pic's of what is involved here somewhere. (Search: 120 amp Denso) Over a year now and still love it, it can output over 60amp @ idle if needed and retains factory wiring routing. (1 wire alt. will "backfeed" the entire system.) The entire electrical system on my car is still stone stock with no issues. The replacement "OEM" brand ALT gauge is higher rated (60 amps) and a good recommended upgrade also. If you fed the fans controller off the alt output stud and ran another wire to feed the other high draw items (Keeping them off the factory wiring.) I think you would be fine. This kit uses that later model Denso Chrysler used that was mentioned. It is Denso part # 210-0138. 

[andben]

Got it!

http://www.dodgecharger.com/forum/index.php/topic,70008.0.html

Thanks alot!

[b5blue]

 That's it. In your case I'd install a junction terminal fed by a good size wire off the output stud to distribute power to the car and add on components. (That's what I'll be doing later.)
  Having installed transmitters and receivers in the USAF I'm extra careful making or modifying harnesses and components. I make certain all grounds are flawless, wires are correct gauge for load, connectors are clean and clear of corrosion, (Search: Cleaning connectors with salt and vinegar.) and whenever I can I crimp AND solder then support/seal the connection with heat shrink and liquid tape to provide protection bend or flexing of the weak area where the insulator ends and the wire is exposed for the crimp or connector. 
  My dash is open at the radio area, I'm able to reach in and feel how hot my AMP gauge studs get and have been doing this for over a year. This alt. replaces the discharge from starting the car with more than double the the entire output of a stock alt. so keep in mind you do not ever want to charge a dead/severely discharged battery by running the car.
  I had ignition trouble where my car wouldn't start and was cranked over a lot draining the battery about 30%. When I got the car started I found it took about 7-10 minutes for the studs to get hot. I shut the car down for 15 minutes and re-started it letting it idle for 8-10 minutes more. After waiting 10-15 minutes more I fired it up and drove home with no problem.   

[andben]

I found this one as a "one-wire" install. Cannot use ammeter tho but hey I just need high output!! 

http://chucker54.stores.yahoo.net/postal.html

Anyone tried that one? Need a new wiring from the alt directly to the batt to handle the 140 amp load!

I'll go for that one! just 200 bucks in us, maybe I can get it to sweden for less than $400... 

(toll, customs and other fees is huge! - tell me if you can send it to me like a gift  )

[375instroke]

Sticking with the same design, a higher amperage alternator has larger wires in it.  That means there are fewer turns in the same space.  That causes lower maximum voltage at any given RPM, so going to a higher amperage alternator would cause lower voltage at idle usually.  Does this make sense?  Are there different pulley sizes?  A smaller alternator pulley would spin it faster, bringing the idle voltage up.

[Budnicks]

There are great tech information about this type stuff on amp gauge & charging in Mopars in general at www.madelectrical.com ... the pitcher below doesn't show but, Also I ran a 8ga. wire from the main 1/4" threaded output post on the alternator to the main large post on the "starter relay" at the fire wall, it will help to relieve the strain & shorten the path of resistance for the current, especially at idle... here are some parts & examples... also you should put a 12 volt 30amp Bosh relay or equivalent, in line on any & every added electronics period, like elect. pumps & fans, lights, hot ignition boxes, N20 solenoids, stereo amplifiers, etc., anything that you would add an arming/power switch for... It will help to reduce the spiking & excessive power draws & help your alternator keep up much easier...