69 Dart stalls at night when lights are on and idle drops at stoplight

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DA69RT GT

DA69RT GT

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Took the car out tonight (69 Dart vert) to a local carshow and it stalls at when lights are turned on and idle drops at a stoplight. If I keep it at or slite ovr 1000 rpm no problem but if it dips... it dies. Runs fine underway.

New battery and regulator. How do I check alternator? and could that be problem??? It will also occ stall when have it in N and hit switch to drop top.

Feel something somewhere is drawing on my battery and Im in process of trying to locate.

Any suggestions? Thanks
 
It should run "off the battery". You could have a voltage drop problem in you ignition harness that is causing this. I can visualize a situation, example:

You have a bad connection in either the battery feed through the bulkhead, or the ignition feed coming back out to the ignition system. At very low RPM, the voltage regulator will be feeding full tilt field to the alternator, but it's not turning fast enough to put out. Meanwhile, this is loading down the (bad) connection in the ignition harness, causing ignition voltage to sag.

To check this out, you need to check the drop in the harness from the battery to ignition

You will be checking the path from battery -- starter relay -- fuse link -- bulkhead connector (battery feed red wire) -- to the ammeter -- through ammeter and to ammeter black wire -- to in harness splice -- branch off to ignition switch connector -- through switch -- back out switch connector (on dark blue ignition run wire) -- back out through bulkhead connector -- to ignition system, alternator field, (70/ later) and voltage regulator "I" terminal.

OK take your meter and turn the key to "run" with engine off. If you do not know which is the "key" side of the ballast resistor, check voltage on both sides, and find the HIGHER reading.

Leave this probe connected to the high reading at the ballast, and move the ground probe over to the battery + terminal, or the starter relay battery stud.

What you are HOPING to read is a very low value, the lower the better. If you read MORE than .3V (three tenths of one volt) you do have a drop problem in the harness

Some other issues may be a poor/ bad/ undercharged battery, other harness issues, an alternator that is not outputting what it should, or a much too low idle speed.

What is your idle, "normally" torqflite? In drive?
 
I had the same problim on my dart once this summer did just as yours,i turned up the idle up some and good to go,I bet you get some folks saying at idle your lights are dim and as you speed up they go bright,could i be right 67Dart273 is the alt not putting out enough at idle if my memory is core ct I have a 60 amp alt,with electrionac ing to boot,I must say your the man when it comes to electrical problems.
 
Thanks 67Dart273 and Snake…
Im gonna run a few of the “tests” you listed this week 67Dart273 (if I ever finish putting up the Christmas lights!)
It idles at just under 1000rpm now and drops to about 800 when put in drive. I turned the lights on today and goosed it up to 1000 in drive w/foot on brake and it was fine. As soon as I let my foot off the gas… died.

I orig had issue with dim headlights that would brighten as I accelerated… switched to the blue "racing" regulator (see pic). Could that be an issue? Yea, I know... I gotta clean up and secure those wires still.
I also have a new pos battery cable I plan on putting on just in case there may be issues as it looks like it was pieced together- question reliability.
If I cant figure it out I guess my only other option is a new alternator. Are there diff opt in Alt’s? Can you go more than 60Amps or do you start running into voltage/fit issues?
Thanks again guys.
 

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No, its not the alternator. I bet your carb is real lean or your timing is off. Give both a shot, they are free to try.
 
To quickly check the Alt, remove the 2 wires at your regulator and jam 'em together. You should hear the alt kick-in and the idle slow down, as what you're doing is "Full-Fielding" the alt, which means its charging full blast...DON'T rev the engine with the wires connected this way. This is just a quick test to make sure the alt is actually charging. If it is charging well, then your problem could be the regulator.

Another "free" test.

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pishta- funny you should mention that. Car has been a little sluggish/hesitant out of 1st gear lately (occ bogs). Was gonna clean carb real well- change fuel filter and check timing. Wanna pickup a vacuum gauge so I can better set air/fuel mix screws.
Thanks


65Val- as noted... not a big fan of electrical issues. No chance of getting a taste of my battery is there???? Been shocked good one time in my life... still feel it.

Reminds me of this video- one of my favorites:

[ame="http://www.youtube.com/watch?v=VZ4mz-khXIo"]Banana Shock Joke - YouTube[/ame]
 
i had a similar issue and it turned out (after much wire chasing, testing) to be a bad main battery ground. Dont hurt to try that if the others dont work.

Good luck!
 
Thanks- thats the 1st thing I checked- pulled off ground to body and engine and sanded/cleaned well. Like I said- I do have some concern on the quality of my positive cable though... need to get up in air though to get to starter connections.
 
Ive been running 100 amp alternator on mine for 4 years with no problems.
 
DA69RT GT said:
65Val- as noted... not a big fan of electrical issues. No chance of getting a taste of my battery is there???? Been shocked good one time in my life... still feel it.
Click to expand...

Your battery won't explode, and you won't get shocked, but there will be a small spark if your alt is good. You just do it quick (a few seconds will determine good alt or not) and DON'T rev it up!!! I've done this countless times to check alt condition. Set your idle around 700 in neutral.
 
it does not sound like an electrical problem but your carb sounds it like it is out of tune. i had a freinds 64 Buick Special and redid the brakes and fuel. as the brakes went out 2 years before. well got it running and it surged and had to two foot it but after carb was tuned in it ran great
 
DA69RT GT said:
… switched to the blue "racing" regulator (see pic). Could that be an issue? .
Click to expand...

Make DAMN sure that thing is grounded. Remove it and (if used) electronic ignition box, and scrape clean behind the mount ears, as well as around the mounting holes on the firewall. Mount using star washers. It does not hurt to make a "daisy chain" ground of no12 were, hook between one bolt on the regulator, and one on the ignition, and run to the body, and finally to the engine.

On mine, I use one of the unused rear head bolt holes (look at the front of your passenger side head, these same bolt holes are on the rear of the driver side head) I use about a 1 ft long "starter" cable (ring to ring) between one of these bolt holes and one of the master cylinder bolts.
 
Read 67Dart273's posts closely. He is right on everything. It should run off the battery alone. The alternator just recharges the battery (thru the ammeter). The main interaction between headlights and ignition that I can imagine is in the grounding. I can imagine that only for an electronic ignition module grounded to the body.

Re a bigger alternator. Your 69 (round-back) would have been ~30 A, though someone might have upgraded it higher since J.C. Whitney and others sold kits. The late 70's ones (squareback) were ~70 A. You can use with your existing wiring if you ground one field terminal (either one). I just bought a 114 A alternator off ebay, intended for older Mopars (retro-fit?). It looks like GM w/ external fan. Cost $55 w/ shipping. Autozone sells ~$110. I will only use if needed. The old round-back alt has worked fine for me for years w/ TBI and an electric fuel pump in my Newport. Best to bypass your ammeter and bulkhead connector within the engine bay if you go big amps. Otherwise, you may see smoke under the dash. Or use my bypass diode idea to keep your ammeter.
 
UPDATE:
Think I finally got it "figured out". Just not sure what was the final solve...

Noticed ground wire from back of alternator to manifold was not great so made a new wire w/connections and made sure ground area was clean.
Cleaned ground strap from engine to firewall.
Sanded firewall behind regulator and checked all other battery grounds again.
Put in new spark plugs (worn to .40) and checked timing (ok), adjusted carb.

When lights are turned on... maintains idle!!!
Not sure what was the resolve but fingers crossed.

A buddy told me I should put in a new 100A alternator that has the regulator built in (?) Anybody know anything about these???
Guess my biggest fear would be old/faulty wiring harness and possible Alt issues.
 
Is this the regulator you bought?

Voltage Regulator, 13.5 V Constant Output, Race Only, Chrysler, Dodge, Plymouth, Part Number: DCC-3690731

Just guessing, but not too many blue ones out there. The two words right before "Chrysler" in the description would put me off in search of a different one.

ATB

BC
 
I think thats the one... I got it from the parts dept @ my local dealer.
Ill check the p/n tomorrow.
 
Any good or bads in regards to the blue regulator?
Has kept my headlights from dimming due to idle but heard it can be hard on battery/alternator?

Thanks for the article! Remember seeing that once but never saved it.
 
This thing has generated a LOT of controversy because of the wording, year after year, in the MP catalog, which has (had?) a disclaimer about "race only."

As long as it's properly grounded it should work just fine. Check your running battery voltage after it has normalized. After starting, warming up, and getting the battery fully charged, your voltage, running, at the battery, should be 13.8--14.2 volts, in no case lower than 13.5, and not higher than 14.5

This is also one reason that I'm always preaching to "check voltage drop" on the ignition run buss. If there is drop in that circuit, the regulator will "see" lower battery voltage, and will ramp up charging voltage to compensate. That is, if the regulator is properly regulating to say, 14, the drop in the harness, whatever that figure is, will be added to the battery running voltage.
 
Thanks for all the feedback! Everything seems to have resolved... gonna leave the Blue Racing regulator on
 
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