charging issues on genIII swap

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mcat

mcat

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i had done a search but still have questions, i didn't want to jack other threads so i started this..06 hemi and alt. in 68 barracuda. megasquirt EM
every single wire/plug are brand new. i am using an external regulator. its a 68 single wire configuration. it is the modern electronic version.
i grounded one of the field wires on the alternator. the other field i ran to the new regulator.
i have the keyed wire from my brake light switch powering the regulator. i have a 4gauge wire straight from the alternator to the hot side of my ford starter solenoid, the fuse box is powered to the hot side of the solenoid too. everything works as it should,
BUT all my lights flicker
and if i unplug the keyed wire from the reg. the engine runs better and lights stop flikering
WHY?????
 
You lost me at keyed wire on brake light switch. I don't know of that.
Good luck though
 
That's still not right. Alternator field and the voltage regulator should be supplied by blue w/white tracer from ignition switch.
 
okay. regardless of the power source for the regulator,it is powered when the key is on.. does the field wire need a power source also?
 
You are running a pre 70 regulator?

Most these voltage problems are caused by grounding / voltage drop problems

Sometimes it can be a defective regulator. Especially suspect are the older ones "relay" type. Look under the base of yours. If there are two large wirewound resistors, it's a relay. Most older type (pre 70) regulators have "by now" been replaced, and most replacements are actually solid state inside the "old type" box

Learn about voltage drop. It's much easier to measure drop with your meter directly because you don't have to take two readings and subtract.

EG: Hook one probe of your meter to the VR IGN terminal. Hook the other probe DIRECTLY to the battery post, IE stab the probe right into the top of the post. Obviously if you have a trunk--mount battery, you'll need a long wire extension. A piece of no14 or so is just fine.

With the key in "run" but engine stopped, set the meter on low DC volts. You are hoping here for a very very low reading, the lower the better. More than about .3V (three tenths of one volt) means you have a voltage drop problem

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

Check the ground side. This you do a bit different. Clip one probe to your meter direct to the battery NEG post. Stab the remaining probe into the mounting flange of the VR. Stab through any chrome, paint, rust. This time, you want the engine running, the battery charged up after starting.

Take the reading with the engine running at a good "fast idle" or "low cruise" and first with all accessories off, and again with heavy "stuff" like lights and heater turned on

As before, you are hoping for a low reading, lower the better, and zero would be perfect. More than .2--.3V means you have a problem

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

If these tests show OK I would try a different regulator. Buy the best one you can find. One that used to be considered "great" was the Standard / Blue Streak VR-128. The NAPA / Echlin equivalent is VR-1001

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

Also just for grins, check your running / charging voltage. Check this right at the battery, and then up front wherever your power is pulled off to feed the car

Tell us a bit more about power distribution in the car. I detest having to use a crowbar to get information out of people. I'm guessing you have a trunk mount battery.
 
67Dart273 said:
You are running a pre 70 regulator?

Most these voltage problems are caused by grounding / voltage drop problems

Sometimes it can be a defective regulator. Especially suspect are the older ones "relay" type. Look under the base of yours. If there are two large wirewound resistors, it's a relay. Most older type (pre 70) regulators have "by now" been replaced, and most replacements are actually solid state inside the "old type" box

Learn about voltage drop. It's much easier to measure drop with your meter directly because you don't have to take two readings and subtract.

EG: Hook one probe of your meter to the VR IGN terminal. Hook the other probe DIRECTLY to the battery post, IE stab the probe right into the top of the post. Obviously if you have a trunk--mount battery, you'll need a long wire extension. A piece of no14 or so is just fine.

With the key in "run" but engine stopped, set the meter on low DC volts. You are hoping here for a very very low reading, the lower the better. More than about .3V (three tenths of one volt) means you have a voltage drop problem

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

Check the ground side. This you do a bit different. Clip one probe to your meter direct to the battery NEG post. Stab the remaining probe into the mounting flange of the VR. Stab through any chrome, paint, rust. This time, you want the engine running, the battery charged up after starting.

Take the reading with the engine running at a good "fast idle" or "low cruise" and first with all accessories off, and again with heavy "stuff" like lights and heater turned on

As before, you are hoping for a low reading, lower the better, and zero would be perfect. More than .2--.3V means you have a problem

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

If these tests show OK I would try a different regulator. Buy the best one you can find. One that used to be considered "great" was the Standard / Blue Streak VR-128. The NAPA / Echlin equivalent is VR-1001

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

Also just for grins, check your running / charging voltage. Check this right at the battery, and then up front wherever your power is pulled off to feed the car

Tell us a bit more about power distribution in the car. I detest having to use a crowbar to get information out of people. I'm guessing you have a trunk mount battery.
Click to expand...
thank you.. battery is up front..
 
mcat said:
thank you.. battery is up front..
Click to expand...

Well a few more details

67Dart273 said:
Tell us a bit more about power distribution in the car. I detest having to use a crowbar to get information out of people. I'm guessing you have a trunk mount battery.
Click to expand...

See, there's a REASON why I said that. "We ain't there."

You mentioned a Ferd starter solenoid. Why are you using one and how is it wired?

How does it tie in with the rest?
 
as mentioned, everything in the car from the fuse box is stock. the fuse box gets power straight from the battery cable(0/1 gauge) from the ford solenoid post . the hot wire from the alternator(4gauge) goes to the same hot solenoid post. the yellow wire from the factory solenoid powers the ford solenoid when the key is turned , a 0/1 gauge wire goes from the dead side of the solenoid to the starter. the 2 starter posts are tied together. this is a hemi swap...everything is new, the engine and everything else is grounded straight to the battery, no chassis grounds are used . new ground straps everywhere..
 
How is the VR grounded?

You say you have "no chassis grounds" but this is misleading, because these are a unibody. "There is no" chassis." Since SOMETHING in the car has to be grounded to the body, what do you have from engine to body?
 
67Dart273 said:
How is the VR grounded?

You say you have "no chassis grounds" but this is misleading, because these are a unibody. "There is no" chassis." Since SOMETHING in the car has to be grounded to the body, what do you have from engine to body?
Click to expand...
wow... if there is anything that takes a ground...it has a wire grounded to the battery/cable. i do not rely on body/chassis grounds. but i do have the body grounded with new ground straps this car is over grounded.... i did not want to take any chances with the new electronics
 
All I can say for now is run the tests I posted earlier, and if they don't result in "anything" try a different regulator
 
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