Charging issue

[Rockboyz]

Hey Guys, I'm sure this has been asked, I didn't see it anywhere. 72 challenger, 318 car, now 340. original alt. 12.25 running at the battery. I'm thinking about replacing the alt and the voltage regulator just because of the age. I'll check all the wire while I'm at it. How do I find out what amp this alt is? I see a variety of amps available. and should I consider a strong amp alt? Many thanks in advance guys!

[Beekeeper]

I had a similar issue years back with my 70 Bee and a couple guys in here recommended a simple improvement that fixed everything. They had me run a 10 gauge wire from the large post at the back of the alternator directly to the large positive post at the solenoid.

The thinking was that the original system ran everything through the dash wiring which was lengthy and had smaller diameter wiring. In doing so, there was a lot of resistance which caused a big voltage drop by the time it gets to the battery. By adding this wire, you create a bypass and electricity follows the path of least resistance. Simple and requires no other wiring changes. My voltage went from 12 to 14 immediately and never had an issue again. Only drawback is the ammeter gauge isn't very useful since less current flows through it. Best part is you could try it for only the cost of three feet of wire and a few minutes of your time and if it didn't work, you lose almost nothing.

I don't profess to be an expert on electrical stuff, in fact I know very little. I just know I followed the advice from guys in here and was very happy.

[Bullitt-]

I've never had an alternator fail, had to replace the brushes on one that was high mileage. Possibly the VR but lot's of times it's just poor connections or bad grounds. The VR needs to be solid to the firewall to be grounded properly.
I did upgrade to an alternator for an A/C car just for kicks years ago...can't say it made any difference so unless you've added stuff that demands more amperage I can't say you need to.

[Rockboyz]

Thanks fellas! I think I'll do a little more investigation on all the connections first.

[crackedback]

Could be a number of things,

Use a voltmeter and test output right at the alt charge stud.  If it's much higher than what you are seeing at the battery, you have a lot of resistance in the charge line.  If it's the same as the battery or very close, then look at the other items in your charging system and the voltages triggering them.

You could make up a jump wire from a piece of 12ga to test out the system direct from alternator to battery post or starter relay.

If you do a wire around, that essentially removes the ammeter and bulkhead from the charging circuit. Some love the ammeter, others like me find it to be a useless gauge that can be replaced by other monitoring methods.

If you do find a lot of resistance in the line, I build wire arounds in both 8ga with a 12ga fusible link and straight 6ga wire.

 

[Chryco Psycho]

normal voltage running should be 13.8 to 14.2
 using a direct wire from the alt to the bat terminal on the start relay also makes a lot of sense as it will bypass the marginal firewall connections & the ammeter which can cause fires due to resistance there

[Rich G]

The amp size is stamped on the alt.

[Cudakiller70]

This is something worth considering for older Mopars with amp meters.
http://www.madelectrical.com/electricaltech/amp-gauges.shtml

[Mpdlawdog]

 

[crackedback]

This is something worth considering for older Mopars with amp meters.
http://www.madelectrical.com/electricaltech/amp-gauges.shtml

People like to follow that set up.  Not my preferred way to wire around.

My way is easy, run a decent sized wire from alt stud to starter relay and leave everything else in place.  No slicing and dicing of the harness required.  Just check the existing harness for damage and fix anything that is out of sorts.

[Cudakiller70]

People like to follow that set up.  Not my preferred way to wire around.

My way is easy, run a decent sized wire from alt stud to starter relay and leave everything else in place.  No slicing and dicing of the harness required.  Just check the existing harness for damage and fix anything that is out of sorts.

Doing that would take the load away from the amp meter circuit?

[crackedback]

Doing that would take the load away from the amp meter circuit?

Pretty much.  The OEM wires will basically carry whatever loads the interior of the car requires and the main charge load travels the new larger wire.

[73440]

People like to follow that set up.  Not my preferred way to wire around.

My way is easy, run a decent sized wire from alt stud to starter relay and leave everything else in place.  No slicing and dicing of the harness required.  Just check the existing harness for damage and fix anything that is out of sorts.

Thank you crackedback, looks like the way to take care of that. I had read and saved the madelectrical article and it was on the project list but the alt output to starter relay looks the way I will do.

This article has some more info on that. http://www.allpar.com/history/mopar/electrical.html

[Cudakiller70]

Pretty much.  The OEM wires will basically carry whatever loads the interior of the car requires and the main charge load travels the new larger wire.

Got it. If existing wires in good shape from fuse block to gauge all is well and just add wire as you said above.
Your headlight relay kit is still on my list, I just need other stuff to stop breaking 
Is there an issue with amp meter failure with time?

[crackedback]

Got it. If existing wires in good shape from fuse block to gauge all is well and just add wire as you said above.
Your headlight relay kit is still on my list, I just need other stuff to stop breaking 
Is there an issue with amp meter failure with time?

It's the bulkhead connector area that is problematic.  Where the black wire from alternator power enters and red wire where it continues out to the starter relay.  Many times this area is melted badly from heat/resistance.

The ammeters have been known to catch fire.  I take them out of all my cars.  Garbage gauge IMO and a voltmeter will tell you what you need to know regarding charging conditions. 

Yeah, stop breaking stuff, I gotta eat.  LOL      
Let me know when you are ready.  Thanks   Rob