proper wiring

[biginch=bigfun]

Alright, I need a little help figuring somethings out...again. The more I read about wiring the more lost i get. So I'd like to detail what I have & hope someone can tell me how its suppose to be hooked up & I can verify I have it correct or trace down a problem.

1969 Road Runner
440/ auto.
MSD 6AL
factory electronic distributor
2 wire alternator
2 prong ballast
blue volt regulator w/ single post grounded to intake & firewall
optima dry cell battery grounded to aluminum intake
bypassed alt gauge
new autometer volt gauge

problems:
constant flickering lights @ all rpms
headlight & dash lights drop out completely
voltage will range from 11 to 15

thanks in advance

 

[440roadrunner]

The MyMopar wiring is a help, but they are not close to complete, and a few of them are flat incorrect.

Go over to this thread at FABO and download a free factory shop manual. I believe the 69 manual posted is "Dart/ Charger/ Coronet" but the wiring for Coronet is the same for Belvedere

The thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309

You will have to scroll down because some of the first links posted are broken, and got fixed later in the thread. Link to the 69 manual:

http://www.abodyjoe.com/pictures/Mis...e manual.pdf

In your viewer, type page 8-1 for the electrical index

Diagrams start page 8-96

Your voltage problem is most likely due to VOLTAGE DROP in the ignition harness. The circuit path we are talking about here is outlined in the MAD article, scroll down the page and look at the simplified diagram:

http://www.madelectrical.com/

this article:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

The circuit starts at the BATTERY -- FUSE LINK -- BULKHEAD CONNECTOR -- AMMETER -- WELDED SPLICE -- not shown -- IGNITION SWITCH CONNECTOR -- through the SWITCH -- back out the SWITCH CONNECTOR -- out the BULKHEAD CONNECTOR (on the dark blue ignition run wire) -- and to the IGNITION, and REGULATOR IGN terminal.

Your top suspects for voltage drop are the

bulkhead connector, including the charging line, (black), battery feed (red) and ignition run (dark blue)

the ignition switch connector

the switch itself

in more rare cases, ammeter connections and the ammeter itself

in very rare cases the welded splice

I realize you have bypassed the ammeter, but did you FIX the bulkhead connector?

Now, to check the system for voltage drop problems, follow these steps

1---With your voltmeter set to low DC volts, hook one probe to the battery (starter relay stud) and the other probe to the regulator IGN terminal. Turn the key to "run" with engine off. You are hoping for a very low reading, the lower the better. More than .3V (three tenths of one volt) is too much and shows drop in the above described circuit

2--Check the ground path for the regulator. The blue regulators are VERY troublesome because you MUST be CERTAIN that you scrape the paint away from the mounting bolts, and use start washers, as well, of course, of having clean bolts and metal under the regulator

Start the car, get the battery "normal" if possible, and run the engine to simulate "medium cruise." Again, with the meter set on low DC, stick one probe on the battery NEG post, and the other on the regulator mounting flange. Be SURE to stab through any rust, chrome, or paint.

Again, you are hoping for a very low reading, and over .2--.3V means a poor ground

3-- With the engine still running and your meter set to measure battery voltage, see what the charging voltage actually is under these conditions. (Sounds like you already did that)

Here is how a typical harness drop like this works. On my 67, it originally had ONE VOLT!!!! of drop. The regulator uses the "ignition run" at the regulator IGN terminal for sensing. In my case, with a one volt drop, the regulator was correctly trying to charge the battery at 14V, but it SAW one volt LESS at the ignition terminal, so it ramped up alternator voltage until it "saw" 14V at the IGN terminal. BUT the one volt drop in the harness means that the BATTERY is now charging ONE VOLT higher -- at 15V!!!

 

[biginch=bigfun]

Thanks 440 RR. But i have already done this & the 1969 wiring doesn't cover the changes made to the car over the years.
I found the MAD article really informative. Your quick response is greatly appreciated!
Louis

 

[440roadrunner]

OK. The voltage to the regulator, and the ground test, still apply, though

 

[Jeremiah]

You can eliminate the ballast resistor when using an MSD. You will have to tie the "start" and "run" circuit together so you have power to your fancy MSD box during both cranking (start) and when the key return to on when you let go of it (run). Whne you say blue regulator do you mean the Mopar Performance constant output unit? Those are not ideal for the street. Also, when you say it is a "single post grounded" I assume you did not ground the post to ground, correct? Listen to 440RR he is on the ball with this stuff.

 

[99ss]

:headbang:

 

[tpodwdog]

replace ALL the fusible links and GROUNDS GROUNDS GROUNDSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

 

[paladin06]

This thread was very helpful.

OK, I was pulling the connectors at the firewall and they look horrible. I noted the wire at position "P" is not connected on the female side. My shop manual wiring diagram show this wire runs to the FLD side of the ALT. How do I pull the female connector from the firewall so I can repair the wire. Looks like someone remove the female side connector and connected the wire behind the firewall.

Please advise.