Charging problem - Part II

[Al K]

I had to run an additional wire to the battery (or starter since it is trunk mounted) when we were having voltage issues. The car would only charge around 11.5V when it should be 13-14V. If it is an everyday driver, eventually this will lead to a dead battery, especially while cranking over a higher compression engine. The factory wiring was not sufficient for even the 65AMP alternator. An easy way to check this is to simply cut a piece of heavy gauge wire, hook it up to the battery post terminal on the alternator (as an addition to the factory wiring) and hook it up to the positive side of battery or even the starter relay if the battery is trunk mounted. If you see your voltage increase, then obviously you know it is your wiring.

What gauge wire did you use for this? Any minimum/maximum gauge recommendations? I'm fighting a low voltage issue myself-with all new alt/reg/ballast resistor/good battery and I'm stuck at 11.2 volts on the inside gauge. Gauge checks out. Bulkhead connections cleaned and greased. I'm following this thread(all three chapters) to see if I can figure this crap out before I post my own thread on the matter. Thanks!

Carry on...


UPDATE!!! Had some 14 gauge around,so I made a jumper running from the alternator stud to the starter relay. Figured it might be too small,but I've been f@#$%&*g with this for a week,and was ready to try something. Guess what? IT WORKED!!! I started the car,saw the gauge sit at 11 or so,and then...the needle started moving-in the correct direction! Settled at around 12.2 at idle,went to 12.5-6 when revved. Way cool! I still want to go to larger wire,either 12 or 10 gauge.

 

[Sweet5ltr]

Happy it worked out for you! Some people just make issues too complicated (showing pictures of complete factory wiring diagrams, routing you everywhere but the place you need to be :eusa_think.. I like just keeping things simple.. I'm around 13-13.5V. I believe I am using either an 8-10G wire..

 

[Al K]

Hey;I'm grateful for some of those diagrams. They've helped me figure out where the current flows. One more question: Can this supplemental wire be kept on there? I wasn't planning on removing the original wire(until I can get a whole new harness);just looking to avoid the under-charging issues.

 

[Al K]

Oh boy...another potential problem,and AR67GTX may consider this.

Replaced the 14 ga. wire with a 10 ga. piece. Started the car;watched the voltage go from 11.2+ to 13 volts as the system warmed up. Then...Revved the motor a couple of times and watched the voltmeter climb to 16 volts! I cruise at 2800-3000 rpm at 70+ mph on the x-way;don't need THAT much charge going down the road. Should I put some sort of resistor in that line(from the alt. stud to the starter relay) or is this not a problem? I want to drive my car this week and weekend!

 

[Sweet5ltr]

Hey;I'm grateful for some of those diagrams. They've helped me figure out where the current flows. One more question: Can this supplemental wire be kept on there? I wasn't planning on removing the original wire(until I can get a whole new harness);just looking to avoid the under-charging issues.

Yeah, some of those diagrams were helpful the first few times I tried solving this issue. Also Helped me solve some brake light and turn signal problems as well. I am still running the wiring, six months later.

 

[440roadrunner]

Either the battery has a problem, the regulator is defective, or it is not receiving proper "sense" voltage from the battery, OR the regulator is not grounded to the battery

To check this out, do the following:

1---- Make sure the battery is charged and have it load tested. Better yet, if you have another vehicle with a properly operating system, and a known good battery, temporarily swap the battery

===================================

Voltage checks:

2---- Set your meter for low volts

Hook one probe to battery +, such as the starter relay stud

Hook the other probe to the regulator IGN terminal (the "push on" one if you are still using the 69/ earlier system

Turn the key to run but leave engine OFF. You are hoping, here, for a very LOW reading, the lower the better. If you read MORE than .2--.3V (that's three TENTHS of ONE volt) you have a voltage drop problem in the ignition harness.

Your top suspects are the bulkhead connector, the ignition switch connector, or the switch.

3---- Start the car, and run it on the fast idle cam to simulate "low to medium" cruise .... and.......

Hook one probe again to your battery NEG post

Stab the other probe directly into the mounting flange of the regulator. Be sure to "stab" through any rust, chrome, or paint. You again are hoping for a very low reading, the lower the better, zero would be perfect. ANY voltage, even a few tenths of a volt, indicates a poor ground between the battery and regulator.

4---- If the two tests are OK, you might run them again to be SURE If so, replace the regulator.

 

[mjb765]

mine charges 14.5-15 on the highway and I used to think that was high!!!

 

[Hemi Rebel]

mine charges 14.5-15 on the highway and I used to think that was high!!!

that is high. 14.5 is the upper end of perfect. Anything over that and you are not doing your battery any favors. Charge rates @ 14 to 16 volts are probably like 8 hours, but that battery is gonna be hot after 8 hours. I like 13.5 to 14. Any lower or higher and Im watching that guage like a hawk, in case something craps out.

 

[440roadrunner]

that is high. 14.5 is the upper end of perfect. Anything over that and you are not doing your battery any favors. Charge rates @ 14 to 16 volts are probably like 8 hours, but that battery is gonna be hot after 8 hours. I like 13.5 to 14. Any lower or higher and Im watching that guage like a hawk, in case something craps out.

I agree. Regulators are temperature sensitive, and if you "read the book" they detail typical temp/ voltage curves.

But for "normal" "warmed up" and "running down the road" you should see 13.8-14.2, not lower than 13.5 for any length of time, and not higher than 14.5 for any length of time.

THE TWO BIG THINGS which cause overcharging in traditional Mopar systems is

1 Voltage drop in the ignition harness, IE the regulator does not "see" true battery voltage

2 Poor ground between battery and regulator.

 

[coloradodave]

440roadrunner: You seem to know a lot about automotive electrical systems and give excellent, easy to follow trouble shooting guides. What's your background?

 

[AR67GTX]

Well - unfortunately sticking a new, rebuilt alternator on the car didn't seem to fix anything. Still seems to be stuck at around 12 volts. My testing expertise must be sucking big time.

It's strange - the battery seems to be taking this all way too well. It spins the motor over like a champ considering it doesn't appear it's getting sufficient voltage from the alternator to fully charge.

I'm now wondering if my alternator gage connections need cleaning and tightening. It acts like it's about dead and fluctuates very little as the motor is reved up or accessories are turned on. I had the dash out about 8 or 9 years ago when I had the instruments rebuilt. But, maybe something is loose now. I'm doubtful the bulkhead connector is the issue. I've had it apart a couple times, once to clean the terminals and they look in good shape.

Anyway, kind of stuck for now waiting on this hurricane to get here and move through. Then it will be back to testing.

 

[RustyRatRod]

Oh boy...another potential problem,and AR67GTX may consider this.

Replaced the 14 ga. wire with a 10 ga. piece. Started the car;watched the voltage go from 11.2+ to 13 volts as the system warmed up. Then...Revved the motor a couple of times and watched the voltmeter climb to 16 volts! I cruise at 2800-3000 rpm at 70+ mph on the x-way;don't need THAT much charge going down the road. Should I put some sort of resistor in that line(from the alt. stud to the starter relay) or is this not a problem? I want to drive my car this week and weekend!

If the battery has not been charged properly for sometime, it's perfectly normal for the charging voltage to be high until the battery is up to a proper charge.

 

[440roadrunner]

If the battery has not been charged properly for sometime, it's perfectly normal for the charging voltage to be high until the battery is up to a proper charge.

Sorry Rusty, no. The AMPERAGE will be high, depending on how big the alternator is, but the voltage may actually run LOW somewhat, and should CERTAINLY be nowhere near 16!!!!

 

[mjb765]

that is high. 14.5 is the upper end of perfect. Anything over that and you are not doing your battery any favors. Charge rates @ 14 to 16 volts are probably like 8 hours, but that battery is gonna be hot after 8 hours. I like 13.5 to 14. Any lower or higher and Im watching that guage like a hawk, in case something craps out.

I agree...but after a rebuilt alternator and a new voltage regulator, I am leaving until the winter. I have an ammeter bouncing issue also...so over the winter I am having the ammeter converted to a voltmeter, replacing the factory wiring and installing a 1 wire alternator.

 

[440roadrunner]

440roadrunner: You seem to know a lot about automotive electrical systems and give excellent, easy to follow trouble shooting guides. What's your background?

Old fart

Amateur radio op in high school in 65. Navy electronics 68--74. During that time, I owned a 69 383RR, a 70 sixpack car, and a 64 440 (body) with a 426. I also had a gutted former Pikes Peak '70 Cuda for awhile that I drag raced a little.

During my time at Miramar (Top Gun, but no Tom Cruise!!) I helped many friends fix their cars. Found my first failed "in harness splice" in about 70-71 on a friend's 68 RR We tore the entire dash / cluster apart in the parking lot of his apartment in the RAIN, rare for San Diego!!

Been somewhat in/ out of electronics all my life, spent quite a few years maintaining/ installing HVAC/R, and the last few working years for Motorola, tower climbing and all.

Now that I'm 64, I can barely walk.

 

[coloradodave]

Well, keep up the good advice. And as far as walking, at 68, I'm with ya.........

 

[Al K]

OK,a bit of a follow-up: Replaced the wire from the stud to the bulkhead. Also replaced the alt. field wire. Added a couple of extra ground wires as well. Have not been under the dash,and I'm thinking that my (lower-than-normal)problem is a combination of a corroded bulkhead(the internal connections) and the wires running to/from the ammeter gauge on the dash. I've got two brand new batteries here and switching them didn't alter anything. Still have about 11.7-.9 on the interior gauge,my ammeter displays a slight "discharge" but I don't seem to be drastically draining the battery when driving. Tried the "jumper" one more time after replacing and repairing the other wires,and got the same result. After a short amount of running time,the voltage climbed when revved to 16. Went back to about 12.2-.3 at idle.

AR67GTX;please don't think I hijacked your thread. Your problem was eerily similar to mine;hopefully,we all benefited. Electrical issues (almost) make me want to start drinking again. NOOOOOOO!!!!!!!

 

[RustyRatRod]

Sorry Rusty, no. The AMPERAGE will be high, depending on how big the alternator is, but the voltage may actually run LOW somewhat, and should CERTAINLY be nowhere near 16!!!!

Obviously, you've never put a dead farm tractor battery on the charger. I do it every spring. It pegs my voltage meter on my charger at 18V and gradually drops until the battery has a full charge.

 

[AR67GTX]

AR67GTX;please don't think I hijacked your thread. Your problem was eerily similar to mine;hopefully,we all benefited. Electrical issues (almost) make me want to start drinking again. NOOOOOOO!!!!!!!

No problem - that does sound exactly like my problems (still unresolved). I haven't had much time to work on it recently but I did fully charge the battery the other day and then start it and it still shows low voltage and a slight discharge on the amp gauge. I went out looking for a new regulator (Echiln VR-1001) but as usual NAPA's nearest one was about 1500 miles away and they wanted to charge me shipping to bring it here. I searched the internet for the Blue Streak variety of this HD regulator but was unable to come up with any source. I'm still planning to search for my old one I replaced about 8 years ago and see what happens with it - if I can find it.

So do you think you have found your problem? You mentioned you got voltage to climb at one point but then it fell back to a little over 12 - that sounds like the battery alone - just like mine.

 

[440roadrunner]

Obviously, you've never put a dead farm tractor battery on the charger. I do it every spring. It pegs my voltage meter on my charger at 18V and gradually drops until the battery has a full charge.

Rusty, chargers are different. Most of them are not regulated, and those that are are "poorly" regulated, and the faster you try and charge (by turning up the rate switch) the higher the voltage output. Automotive systems do not do that. They attempt to regulate at the reagulator set point of nominal 14V. In fact, most automotive systems trying to bring up a dead battery will run somewhat low in voltage until the battery gets "lively."