Here's my set up, 68 cud a with a Indy sm blk stroker using a MSD distributor and 6AL ignition box. Be cooling w/2-electric fans and a Powermaster 100amp+ alternator mounted with March serpentine pulleys. Before installing the stroker, I converted the 340's dual point to Mopars electronic ignition with the supplied ballast resistor. I have checked and double checked all grounds, wire connections, etc.. and my running lights continue to pulse. I ran a fused wire from the alternator to the stater relay to protect the original wires in the dash. I also installed a electronic voltage regulator and a volt meter. The volt meter will spike at 16 volts then drop repeatedly, with a starting reading around 14.5 to 15v. Not sure what or where to look. Questions, If i'm using MSD ignition module, do I need a ballast resistor? SHould I upgrade the resistor to a 4-post? Any thoughts or suggestions sure would be appreciated.
Pulsing Lights.
- Thread starter JamesH
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805moparkid
Slant and AFX Guy
unplug the ign side of the VR... run a jumper from the battery + to the ign side of the VR... if it flattens out its from the VR to inside the car, if not it could be a ground, the VR, wireing, or the ALT...
67Dart273
Well-Known Member
Probably the easiest thing to do (temporarily for testing) is to find out whether the igntion "run" supply is the cause, or the regulator.
Try "rigging" a nice big heavy clip lead, start the car, and jumper the lead from either the battery or the stud on the starter relay to the junction feeding the ignition and regulator. This is normally the "key side" of the ballast resistor.
If this smooths out the problem, you probably have a voltage drop problem in the ignition harness
To check this out, turn the key to "run" engine off. Put one probe of your meter on the battery pos post, the other probe on "ignition run" IE the key side of the ballast, the alternator (blue) field, or the regulator IGN terminal.
You are hoping for a VERY low reading, the lower the better. Over .3V (three tenths of a volt) is too much, and indicates a harness drop problem.
The path affected is from the battery -- fuse link -- bulkhead connector -- ammeter circuit -- ignition switch connector -- through the switch -- back out the switch connector -- (dark blue "IGN RUN) -- back through the bulkhead -- to the junction supplying alternator field, regulator, and ignition system.
Second, check the ground circuit
Run the engine fast, to simulate "med. cruise"
Put one probe of your meter on the battery neg post, the other on the regulator mounting flange.
Again, you want a low reading, lower the better. Over .2v means a poor ground condition between the battery, block, body, and regulator.
If none of the above cures anything, replace the regulator.
There have been rare cases ESPECIALLY with high energy ignitions, that the voltage spikes form the ignition cause noise which "feeds back" into other systems, IE the regulator.
THIS IS why MSD specifies "no solid core wires"
Try "rigging" a nice big heavy clip lead, start the car, and jumper the lead from either the battery or the stud on the starter relay to the junction feeding the ignition and regulator. This is normally the "key side" of the ballast resistor.
If this smooths out the problem, you probably have a voltage drop problem in the ignition harness
To check this out, turn the key to "run" engine off. Put one probe of your meter on the battery pos post, the other probe on "ignition run" IE the key side of the ballast, the alternator (blue) field, or the regulator IGN terminal.
You are hoping for a VERY low reading, the lower the better. Over .3V (three tenths of a volt) is too much, and indicates a harness drop problem.
The path affected is from the battery -- fuse link -- bulkhead connector -- ammeter circuit -- ignition switch connector -- through the switch -- back out the switch connector -- (dark blue "IGN RUN) -- back through the bulkhead -- to the junction supplying alternator field, regulator, and ignition system.
Second, check the ground circuit
Run the engine fast, to simulate "med. cruise"
Put one probe of your meter on the battery neg post, the other on the regulator mounting flange.
Again, you want a low reading, lower the better. Over .2v means a poor ground condition between the battery, block, body, and regulator.
If none of the above cures anything, replace the regulator.
There have been rare cases ESPECIALLY with high energy ignitions, that the voltage spikes form the ignition cause noise which "feeds back" into other systems, IE the regulator.
THIS IS why MSD specifies "no solid core wires"
In 68 the dark blue w/white tracer from igbition switch went to only 2 places, instrument panel to power the gauge voltage limiter and top of the original voltage regulator.
When a powered field alternater, and electronic ignition were added the load on that circuit increased. So when the ignition switch was moved to the column, the switch terminal, wire gauge, etc.. increased. I had already addressed all these differences in my 67 before I ever started the car. Volt gauge needle twitched. New voltage regulator cured it.
Always be sure the regulator is properly chassis grounded before connecting the power to it.
Hope this helps.
When a powered field alternater, and electronic ignition were added the load on that circuit increased. So when the ignition switch was moved to the column, the switch terminal, wire gauge, etc.. increased. I had already addressed all these differences in my 67 before I ever started the car. Volt gauge needle twitched. New voltage regulator cured it.
Always be sure the regulator is properly chassis grounded before connecting the power to it.
Hope this helps.
Well based on everyones input, we tried step by step to find and eliminate the problem. We checked all grounds, ran a wire from the pos.batt to the ign. side of the ballast resistor, no effect. (While the car was running, we pulled all wires from the ballast resistor and the engine kept running.) It appears that when the MSD Ignition was installed the ballast resistor was no longer needed per MSD and the resistor was modified for no resistance. ) Checked the harness for any drop, reading was 1.6, checked all resistance from Batt. to bulkhead connector and bulk head connector back out. All seem good. The problem started when I switch from the old alternator to a power master high out put one. Had the alt. checked and it's putting out the right voltage. Still wonder about the alternator, The pulsing isn't random, it pulses at a regular pattern at idle, when I increase the rpm's the lights get brighter. that why i still think it's the alt. maybe one of the diodes are bad??? Anyway, thats where i'm at, if you have any suggestions, please help.
thanks again for all your help so far.
thanks again for all your help so far.
67Dart273
Well-Known Member
What sort of hook up is the powermaster? Does it use a factory Mopar regulator, or built into the alternator?
Is it "self exciting" (one wire)?
The 1.6 drop. Let's talk about that
IF this is what was measured key on / engine off, from battery to IGN 'run' wire coming out of the bulkhead
THAT IS WAY too much, and is LIKELY the cause of the problem
Two ways to "fix" it.
Either find the problem and correct, or remove all load from the original IGN (dark blue) and use that wire ONLY to trigger a good quality relay under the hood. Get fused power to the relay contacts from the stud on the start relay
If your alternator is using an external regulator, (it's not clear if you already did this) try running a good big wire/ clip lead temporarily DIRECT from the battery to the regulator "I" terminal. See if that temporarily cures the problem, and if so, the "voltage drop" IS your issue
Please go to MSD and read up on their stuff. DO NOT use solid core wires, for example. It might be that the MSD is generating noise on the 12V buss causing the regulator to "hunt."
If you cannot find any other cause, try to "rig" an alternative ignition system temporarily, IE uninstall the MSD It does not cost much, nor is it difficult, for example, to rig an GM HEI module
Is it "self exciting" (one wire)?
The 1.6 drop. Let's talk about that
IF this is what was measured key on / engine off, from battery to IGN 'run' wire coming out of the bulkhead
THAT IS WAY too much, and is LIKELY the cause of the problem
Two ways to "fix" it.
Either find the problem and correct, or remove all load from the original IGN (dark blue) and use that wire ONLY to trigger a good quality relay under the hood. Get fused power to the relay contacts from the stud on the start relay
If your alternator is using an external regulator, (it's not clear if you already did this) try running a good big wire/ clip lead temporarily DIRECT from the battery to the regulator "I" terminal. See if that temporarily cures the problem, and if so, the "voltage drop" IS your issue
Please go to MSD and read up on their stuff. DO NOT use solid core wires, for example. It might be that the MSD is generating noise on the 12V buss causing the regulator to "hunt."
If you cannot find any other cause, try to "rig" an alternative ignition system temporarily, IE uninstall the MSD It does not cost much, nor is it difficult, for example, to rig an GM HEI module
The power master has two fields, hot and a ground. Had to upgrade to a more powerful alternator, The twin electric fans drew to much current. Did find some corrosion in the bulk head connectors, cleaned and reassembled. The 1.6 drop was measured from the positive battery terminal to the ign. on at the ballast resistor. (When we pulled off the wires from the ballast resistor with the car running there was no change, car kept running, we connected the wires from the ballast resistors to each other, again no change, which led us to believe that when the MSD system was installed it was wired with a direct 12v supply. Ran this problem through Mopar Action and the thought was the VR, converted the VR over to electronic using the two wire harness that came with it. This all started when I switched to the higher amp alternator. Is it possible that the alt. has a bad diode or two? ( the Alt. ground goes direct from the alt. to the chassis ground. We tried various jumper wires to check grounds, and alt. field wires. We checked the fused wire resistance from the starter relay to the bulk head connector, 0.1 to 0.2, followed the path coming out of the bulk head connector and didn't find any problems. Nothing was changed or touched in the wiring inside the car or under the dash. Will try another VR just in case. If there is no need for the ballast resistor should I remove it and just splice the wires together? The pulsing lights are very noticeable at idle when the car is first started. With the car running and stepping on the accelerator the volt meter climbs to 16v and the pulsing gets brighter, when the car is driven approximately 30 40 min. the pulsing will decreases to almost nothing.
67Dart273
Well-Known Member
I'm convinced that the pulsing IS RIGHT IN the original dark blue "ign run" circuit
Not knowing how the MSD is hooked up, I cannot address that but "normally"
the MSD has a "power" (big) wire hooked direct to battery IE NOT switched and hot all the time
There will be a smaller wire going to "ign run" which "triggers" the MSD into operation
Sounds to me like you need to bypass the ballast
I am convinced that your problem is right in the IGN run harness path I mentioned earlier
ORIGINALLY this path
starts at the battery, goes through the fuse link from the start relay
through the bulkhead (can be dirty/ corroded/ damaged)
to the ammeter circuit
(ammeter can be loose / corroded)
through the ammeter and to the "in harness splice" This is a splice "on the other side" of the ammeter which branches off to supply UN fused HOT power to..................
the ignition switch
the fusebox "hot" buss
the headlight switch
one or two other things
IF THIS SPLICE has failed, --and they do-- stuff can happen
From the splice, through the ignition switch
(so once again, the IGN switch connector can be loose/ damaged/ corroded, or the switch can be damaged internally)
from the ign switch, back OUT the bulkhead connector (on the "dark blue" "ignition run) and so one MORE set of bulkhead connector contacts can have corrosion/ heat damage/ loose/ etc.
IN ORDER TO TEST this section of wiring, you need to put a LOAD on that circuit. One good way to do this, other than what is already there, is to use one or two "big" lamps, like a couple of stoplight bulbs, or even an old headlight.
Wire this up so that it hooks to the dark blue coming out of the bulkhead and going to the ballast. THIS ALSO FEEDS the blue field lead at the alternator, so you can also hook your lamp there.
So one more time, turn the key to run, the engine NOT running
Probe your meter on battery positive on one probe ---------- and the other probe on the dark blue wire, or the blue down at the alternator field.
IF you are reading this 1.6V you mentioned earlier, you have a BAD connection in that harness path.
So then, with key still in "run"
measure battery voltage, IE 12.X
measure blue field wire to ground, IE 12.X -- 1.6 so 11.x?
Now "backtrack" to find the "drop."
Get under the dash where the IGN switch connector can be accessed, and probe it there. Compare carefully voltage going "into" the switch with voltage coming "out."
If you are not getting your 1.6V difference there, look suspiciously at the bulkhead connector. If there's a goodly difference in voltage between the "dark blue" exiting the IGN switch, and the dark blue in the engine bay at the bulkhead connector, THAT would be an excellent place to start
I BELIEVE I ?? mentioned earlier, that one way to "fix" this is to install a relay out in the engine bay, which will remove the LOAD from the dark blue.
I would guess the reason that this problem diminishes as the battery charges up is that there is LESS CURRENT in the charging circuit, and less current means LESS voltage drop.
What I would guess is happening is that some bad connection (like the bulkhead connector) is causing LOW voltage to the regulator field circuit. The voltage regulator says
"OH **** the battery voltage is LOW, let's CHARGE." So the regulator ramps the voltage up and SUDDENLY the bad connection (shall we say) sort of "arcs across." Now the voltage on the dark blue jumps UP and the regulator says
"OH **** the battery voltage is LOW, let's REDUCE the charge" So the regulator ramps the alternator DOWN, and the bad connection "shows up" again.
This turns into a "Pete Repeat" known as a "low frequency oscillation" in the regulator circuit which is a "feedback loop." That is, "cause and effect."
For an idea of how and why this stuff happens, read this article:
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
From that article is the below diagram, which is a simplified look at the main circuits in the harness
Notice the RED coming from the battery through the bulkhead connector. This connection is your FIRST suspect
Notice the RED goes to the ammeter, which can be loose, corroded
Notice the "welded splice" which Y's off to the ignition switch. This splice can (rarely) be bad
From the IGN switch (not shown) the dark blue "ign run" then goes back through the bulkhead on a DIFFERENT contact in the bulkhead connector. This would be your SECOND suspect
Not knowing how the MSD is hooked up, I cannot address that but "normally"
the MSD has a "power" (big) wire hooked direct to battery IE NOT switched and hot all the time
There will be a smaller wire going to "ign run" which "triggers" the MSD into operation
Sounds to me like you need to bypass the ballast
I am convinced that your problem is right in the IGN run harness path I mentioned earlier
ORIGINALLY this path
starts at the battery, goes through the fuse link from the start relay
through the bulkhead (can be dirty/ corroded/ damaged)
to the ammeter circuit
(ammeter can be loose / corroded)
through the ammeter and to the "in harness splice" This is a splice "on the other side" of the ammeter which branches off to supply UN fused HOT power to..................
the ignition switch
the fusebox "hot" buss
the headlight switch
one or two other things
IF THIS SPLICE has failed, --and they do-- stuff can happen
From the splice, through the ignition switch
(so once again, the IGN switch connector can be loose/ damaged/ corroded, or the switch can be damaged internally)
from the ign switch, back OUT the bulkhead connector (on the "dark blue" "ignition run) and so one MORE set of bulkhead connector contacts can have corrosion/ heat damage/ loose/ etc.
IN ORDER TO TEST this section of wiring, you need to put a LOAD on that circuit. One good way to do this, other than what is already there, is to use one or two "big" lamps, like a couple of stoplight bulbs, or even an old headlight.
Wire this up so that it hooks to the dark blue coming out of the bulkhead and going to the ballast. THIS ALSO FEEDS the blue field lead at the alternator, so you can also hook your lamp there.
So one more time, turn the key to run, the engine NOT running
Probe your meter on battery positive on one probe ---------- and the other probe on the dark blue wire, or the blue down at the alternator field.
IF you are reading this 1.6V you mentioned earlier, you have a BAD connection in that harness path.
So then, with key still in "run"
measure battery voltage, IE 12.X
measure blue field wire to ground, IE 12.X -- 1.6 so 11.x?
Now "backtrack" to find the "drop."
Get under the dash where the IGN switch connector can be accessed, and probe it there. Compare carefully voltage going "into" the switch with voltage coming "out."
If you are not getting your 1.6V difference there, look suspiciously at the bulkhead connector. If there's a goodly difference in voltage between the "dark blue" exiting the IGN switch, and the dark blue in the engine bay at the bulkhead connector, THAT would be an excellent place to start
I BELIEVE I ?? mentioned earlier, that one way to "fix" this is to install a relay out in the engine bay, which will remove the LOAD from the dark blue.
I would guess the reason that this problem diminishes as the battery charges up is that there is LESS CURRENT in the charging circuit, and less current means LESS voltage drop.
What I would guess is happening is that some bad connection (like the bulkhead connector) is causing LOW voltage to the regulator field circuit. The voltage regulator says
"OH **** the battery voltage is LOW, let's CHARGE." So the regulator ramps the voltage up and SUDDENLY the bad connection (shall we say) sort of "arcs across." Now the voltage on the dark blue jumps UP and the regulator says
"OH **** the battery voltage is LOW, let's REDUCE the charge" So the regulator ramps the alternator DOWN, and the bad connection "shows up" again.
This turns into a "Pete Repeat" known as a "low frequency oscillation" in the regulator circuit which is a "feedback loop." That is, "cause and effect."
For an idea of how and why this stuff happens, read this article:
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
From that article is the below diagram, which is a simplified look at the main circuits in the harness
Notice the RED coming from the battery through the bulkhead connector. This connection is your FIRST suspect
Notice the RED goes to the ammeter, which can be loose, corroded
Notice the "welded splice" which Y's off to the ignition switch. This splice can (rarely) be bad
From the IGN switch (not shown) the dark blue "ign run" then goes back through the bulkhead on a DIFFERENT contact in the bulkhead connector. This would be your SECOND suspect
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