restart
Well-Known Member
Your first post item 2 says you had 12V at negative side of coil?
Some help getting engine started
- Thread starter e9Leveque
- Start date
I would say the red hot ballast was a me issue but that seems to be a pretty common issue reported here with the new starter and I think is related to having things hooked up to that always on 12:00 post.
The coil negative side will alternate between 12 volts (points open) and roughly zero volts (points closed). If you measure the negative side with a dc volt meter while the engine is cranking it will read some intermediate voltage. The voltage will be a weighted average of the points closed voltage and the points open voltage. The weighting depends on the on the dwell time ( how much the points are open vs closed over any given cycle
This is precisely the case, it happened to me and I was alarmed to see the red ballast. Always hot when ignition is on and not just starting position.
This makes no sense. The ballast resistor is only powered when the ignition is on. It has nothing to do with the starter. Using an older starter with the black and red wire, the ballast is BYPASSED when cranking. The olny reason the ballast shoudl be overheating is if the coil is shorted.
Scott, while I would agree with you in context, while I was on the phone with Don he told me (before I had told him anything about my wiiring aside from “new starter”) that I should unplug the black/red wire since the resister would get very warm. And indeed it was.
I agree that the resister is supposed to used to handling 12v routinely so why should it matter, except that in our case it’s an unnecessary circuit, as previously discussed. Is yours bright red and hot when activated? Can’t say I had looked at mine before that moment.
And I think the issue was not it getting red hot while cranking, more it getting hot when hooked up to the always-on 12:00 position of the starter
I agree that the resister is supposed to used to handling 12v routinely so why should it matter, except that in our case it’s an unnecessary circuit, as previously discussed. Is yours bright red and hot when activated? Can’t say I had looked at mine before that moment.
And I think the issue was not it getting red hot while cranking, more it getting hot when hooked up to the always-on 12:00 position of the starter
My point was that the starter circuit is supposed to BYPASS the ballast resistor. So the resistor is supposed to be OK with having a constant 12V applied to it. Under normal RUN conditions, the original circuit has 12 volts on the ballast resistor whenever the ignition is on (except in the start position where it is bypassed...
Understood. I wanted to clarify that we are all getting red hot resister NOT when in START position but in RUN position, it’s when the resister is getting the current, not getting bypassed.
I believe you are feeding 12 different circuits in the car through the ballast resister when the black/red wire is hot - all the green circuits
Interesting. So the issue is that if the coil is fed directly from 12 volts when the ignition is OFF (which would only occur if the black and red bypass wire was in place on the newer starter with the always on 12:00 post), then the entire green wire ignition circuit is being fed through the ballast resistor. That makes sense.
Normally, with the old style starter, the black and red wire is energized ONLY when the ignition (green wire circuit) is energized, so this doesn't happen.
One way to preserve the ballast resistor bypass and avoid this issue would be to simply connect the old black and red ballast bypass wire to the starter solenoid START signal (the black wire on the starter). That is only hot when the key is turned to start the engine...
This also appears to answer the question of when is the 12:00 post onthe newer start energized. Some have said it is hot only when the starter is being cranked, others say it is hot all the time. Don's observation indicates that it is indeed hot all the time.
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Once again, on the new starter the 12:00 post is live only with ignition on and when cranking. It is not needed as the newer starters have permanent magnets and crank much faster. With the old SR-71X starter bypassing the ballast allowed a full 12v to the coil during cranking only, as when the engine is running the ballast drops the voltage to 9V to help preserve the points. This short duration didn’t allow the ballast to get too hot. In the early 2002s BMW even used a relay near the coil to trigger the bypass, this was on my 1969 02.
And on another note, when changing to a newer coil such as the Red coil, a resistor with 1.8 ohms of resistance is needed vs. the original black coil which used 0.9 ohms. I found out the hard way when I installed a red coil and didn’t change the resistor on my 2002. The coil would overheat and the motor would stop which happened to me on the freeway. The obvious sign was the tach dropping immediately to zero. After five minutes it would run again.
And in 1974 BMW changed to a ballast wire in all their cars with the same 0.9 ohms of resistance which many owners may not be aware of. A friend had an issue recently where the motor died and would not restart while having a Pertronix installed. The issue was that the Pertronix needs 12V and not 9V produced by the ballast wire. That is why the Pertronix diagram shows the red wire to it needs to come from BEFORE the ballast resistor and if you have the ballast wire it must be removed.
BTW, the e9 and 2002 never used the later Blue coil which is internally resisted to 9V. Some owners install this coil while keeping the ballast, not good!
And on another note, when changing to a newer coil such as the Red coil, a resistor with 1.8 ohms of resistance is needed vs. the original black coil which used 0.9 ohms. I found out the hard way when I installed a red coil and didn’t change the resistor on my 2002. The coil would overheat and the motor would stop which happened to me on the freeway. The obvious sign was the tach dropping immediately to zero. After five minutes it would run again.
And in 1974 BMW changed to a ballast wire in all their cars with the same 0.9 ohms of resistance which many owners may not be aware of. A friend had an issue recently where the motor died and would not restart while having a Pertronix installed. The issue was that the Pertronix needs 12V and not 9V produced by the ballast wire. That is why the Pertronix diagram shows the red wire to it needs to come from BEFORE the ballast resistor and if you have the ballast wire it must be removed.
BTW, the e9 and 2002 never used the later Blue coil which is internally resisted to 9V. Some owners install this coil while keeping the ballast, not good!
That statement seems inconsistent with what you said earlier
So your first statement doesn't align with @e9Leveque's experience and Don's statement above, but your second statement does.
If the 12:00 post is only energized with "the ignition on and when cranking", then that would not cause the ballast resistor to overheat because the ignition circuits would already be energized by the ignition switch (and the main relay). so there would be no current flowing from the starter to the ballast resistor.
If the starter 12:00 post is hot all the time, then I can see that the ballast resistor would overheat because the current would be flowing from the starter through the ballast resistor and to the coil, where it would then flow to the non-energized ignition circuit (green wire). This would draw a lot of current that might overheat the resistor.
This situation would ONLY exist however, when the key was off, since as soon as the ignition was on, the green wire circuits would be powered, and the current though the resistor would stop.
@e9Leveque What were the specific conditions when you had the red hot resistor? Was this with the ignition on or off? Was it only after you set up the "home run" starter wire to the battery? If so, isa it possible that you were cranking the starter with the ignition key off???
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I'll reattach the resistor to the circuit temporarily so that we can sort this out, but I'll say that even though I had the "home run" starter wire hooked up, I would have still had the ignition to the "RUN" status since I would have needed fuel pump relay activated, ECU activated, etc in order for the engine to (try to) start. At this point I should also be able to undo the home run starter wire since the purpose of that wire was to circumvent the ignition circuit to the starter in case that was the reason my engine wasn't starting. Since the result (no start) was the same with or without the home run cable vs standard ignition circuit, it doesn't appear that the issue is upstream of the starter, but rather something downstream.
Was the red hot resistor occurring with the ignition on or off?
If it was happening with the ignition on, then I am wondering if maybe the 12:00 post is connected to ground or the starter winding or something... If it was connected to the starter winding, then current would pass from the green ignition wire on the coil through the resistor and the starter to ground. that might not be enough current to turn the starter motor, but it would be enough to fry the resistor.
If it was happening with the ignition off (a scary thought!), then that would imply that the 12:00 post was always hot, and current was passing from the starter to the resistor and from there to the various green wire circuits, as per Don's explanation above.
Before you attach the resistor, test the 12:00 post with ignition on and off. If it goes to zero volts in one of those cases, test the resistance to ground.
Once we sort out this mystery, we should get back to your lack of spark!
Fuel, injectors, ecu, relays, fuel pump, TPS, MPS, trigger points have no meaning right now. You are looking for spark. No spark- no deal.
Post pics of coil.
I have spare distributors.
Post pics of coil.
I have spare distributors.
I never meant to imply that always hot also included with no ignition. If the key is on to Run, it is hot and stays that way. I can’t explain why this happens but I am telling the truth, when that wire was hooked up to the coil and the green wire was hooked up to the ballast, the ballast turned cherry red and started to smoke, the car was running at that time. When that wire was removed I had normal operation, this is a well known feature of the newer starters, I am not the only one to experience this.
That is SOOO weird, because with the engine running the other side of the ballast resistor (the non-coil side) is at 12 volts, energized by the ignition switch and main relay.
This leads me to seriously wonder if the 12:00 post of the new starter is connected to the starter motor and provides a low impedance path to ground when the starter motor is not turning. Otherwise there is no path for the current to flow.
Success!!’
I wish that I could tell you that I know exactly what the step was that made the difference. I suppose if I go back to the original set up, I could go through part by part and identify what might have failed. As it is right now I have a new Bosch, blue ignition coil, no resistor and a new pertronix. If I had to guess, I think that I had put the car back together with the black MSD coil, which does not have an internal ballot resistor, and apparently put out a smaller spark, which is sometimes difficult systems to work with. I never had reinstalled the original coil in the previous testing.
Alternatively, I also went through and added some more significant grounding between the engine and the frame, so perhaps this was the classic issue of poor grounding.
Either way, the engine does start now. Now it’s on to deal with all the leaks that I’m sure I will encounter. Thank you guys for all of your help working through this. Scott, if you would like I can hook up the ballast resistor to the system temporarily to do the testing above that you had asked to satisfy your curiosity as to the 12:00 post on the new starter.
I wish that I could tell you that I know exactly what the step was that made the difference. I suppose if I go back to the original set up, I could go through part by part and identify what might have failed. As it is right now I have a new Bosch, blue ignition coil, no resistor and a new pertronix. If I had to guess, I think that I had put the car back together with the black MSD coil, which does not have an internal ballot resistor, and apparently put out a smaller spark, which is sometimes difficult systems to work with. I never had reinstalled the original coil in the previous testing.
Alternatively, I also went through and added some more significant grounding between the engine and the frame, so perhaps this was the classic issue of poor grounding.
Either way, the engine does start now. Now it’s on to deal with all the leaks that I’m sure I will encounter. Thank you guys for all of your help working through this. Scott, if you would like I can hook up the ballast resistor to the system temporarily to do the testing above that you had asked to satisfy your curiosity as to the 12:00 post on the new starter.
restart
Well-Known Member
The pertronix has a plastic sticker on it which melts when it’s had a melt down . Sometimes called telltale. You can also smell the burnt internals.
restart
Well-Known Member
The new pertronix circuit protection.
The old ones burnt immediately on reverse polarity and did not take long to destruct if you left the ignition on without the car running.
You said you had an older version. Very easy to blow! 25 cents cents that was the no start problem.
But think of all the wiring you learnt.
Glad you got it figured out. Good work!