Perplexing Ignition Problem
- Thread starter pickman
- Start date
The portion of the ballast resistor voltage drop cannot have worsened by a short as long as the path to the coil primary is not shorted. If the 1.5 ohm primary resistance was measured from the ballast resistor then that is the case. This suggests that the glowing is not from the voltage drop but from the duty cycle (fraction of time the primary current is on). The ignition module has a contactless breaker, so the only way this can happen is if the ignition module is bad (or a short on the - side of the primary coil side).
1) Disconnecting the red wire in the above diagram would incapacitate the ignition module and the car should not fire.
2) Disconnecting the green wire would provide no coil path to ground, the ballast would stay cool and car should not fire.
3) Removing the ballast resistor would only have the starter relay 12V path to the coil, so the car would crank, never start, and the bendix would not disengage, which is what is reported.
4) The ballast bypass suggested is actually to short it, not remove it, and that may make the ignition module glow, so why do that.
I would try 1) and 2) just to prove Arde right, not do 4).
Then I would put a higher resistance ballast (a 12V light bulb perhaps) and put an oscilloscope on the green wire.
1) Disconnecting the red wire in the above diagram would incapacitate the ignition module and the car should not fire.
2) Disconnecting the green wire would provide no coil path to ground, the ballast would stay cool and car should not fire.
3) Removing the ballast resistor would only have the starter relay 12V path to the coil, so the car would crank, never start, and the bendix would not disengage, which is what is reported.
4) The ballast bypass suggested is actually to short it, not remove it, and that may make the ignition module glow, so why do that.
I would try 1) and 2) just to prove Arde right, not do 4).
Then I would put a higher resistance ballast (a 12V light bulb perhaps) and put an oscilloscope on the green wire.
I believe Chris has the right answer - your black/red wire is providing a dead short to your resistor. Your second tell is that the starter keeps spinning when the key is only in the Run position. Appears you will have continuity at 12 and 6 at starter
Yep. If you installed a 440/441x starter that black wire is live with ignition on and it is frying the ballast. Leave it disconnected at the starter, 12:00 position.
Another way to explain- with that new starter you are trying to crank your engine through your resister- oh whoops
The transmission is a 5 speed manual the only switch on it is the reverse light.
OK need some clarification. The starter is the original starter definitely not new however I swapped engines to a 3.5 liter a bunch of years ago. Please explain what the 12:00 position is?
So I put the ballast back in the system with the black/red wire disconnected from the starter?? Yes as far as I recall the ballast has been glowing red for some time.
So I put the ballast back in the system with the black/red wire disconnected from the starter?? Yes as far as I recall the ballast has been glowing red for some time.
If you would please - since removing the wire fixed the problem- check for ground at the black/red connector at starter.
In fact - call me and I will tell you what you need to check behind your head light bucket now.
In fact - call me and I will tell you what you need to check behind your head light bucket now.
I was referring to the 12;00 position on your starter. The 6:00 position is power to crank it. You don’t need the 12:00 wire attached which is black, it sends current full time.
Took a good look at the starter there is the main power cable Fastened to a stud, a black wire fastened to a stud and the black/red wire on a push on tab. which is in the 6 o'clock position. Per discussion with SFDon the red/black should be in the 12 o'clock position but there is no place for it. This is a newer motor than the original 1973 probably a 1978-80 version. Not sure now how to proceed?
Chris Macha gave you the answer- thats a later starter. No place for the black/red wire.
If you want to get clever you can connect the black and the black/red wires to the same new lug and connect that to the starter. Better check that black/red wire first for short to ground,
I had this problem once also -- put a newer starter in my car. It's how I found out that cars of my year have a resistor WIRE instead of just a ballast resistor. Smoke everywhere.
To the question of how I solved it: I took apart the starter solenoid and cut off part of the copper plate that grounds that wire. (I just looked extensively and couldn't find a photo of what I did, sorry.) But, yeah, in summary, the wire that becomes hot during starting used to just become disconnected on the old design. Instead, on the newer starters, it gets grounded after starting, making a short through the starer solenoid. Is that another concise way to put it, fellas?
To the question of how I solved it: I took apart the starter solenoid and cut off part of the copper plate that grounds that wire. (I just looked extensively and couldn't find a photo of what I did, sorry.) But, yeah, in summary, the wire that becomes hot during starting used to just become disconnected on the old design. Instead, on the newer starters, it gets grounded after starting, making a short through the starer solenoid. Is that another concise way to put it, fellas?
Everyone has been excellent to help on this. I will keep the black/red wire off the starter as the only tab for it is at the 6 o'clock position on the solenoid. Make sure the wire is isolated and check the other wires for damage across the front wire loom. Replace the ballast resistor and confirm it does not glow. The engine and tach works perfectly once the black/red was removed from solenoid.
I ran the car for 1000 miles with the previous set-up and a cherry red ballast resistor I see the folly of this now you all have explained Thank you!!
I ran the car for 1000 miles with the previous set-up and a cherry red ballast resistor I see the folly of this now you all have explained Thank you!!
Bit of advice- remove the black/red wire from both connections. Don’t leave hot wires lurking about the front of your car especially if it’s bundled with the green wire that’s been melting. And fuse that yellow wire!
jmackro
Well-Known Member
I would guess that if the ballast resistor was routinely glowing red hot, that it eventually burned to the point where its resistance increased. That caused your coil to receive too little voltage to run properly or to drive the tach (I guess it's just a coincidence that it degraded to the point where the tach would no longer work at the same time you changed your transmission.) So you probably need a new ballast resistor.
But you also need to sort out your ignition wiring and determine why it was causing the resistor to glow red hot - you don't want to subject the new resistor to the same fate. My guess is that the starter - coil wire was causing the ignition resistor supply current to the starter as well as to the coil. With the resistor in place, the circuit couldn't send enough current to the starter to energize the solenoid - but enough to make the resistor glow. When the resistor was absent, that faulty wiring would energize the starter as soon as you turned the key to "ignition".
No, that wouldn't have contributed to this problem.
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Had time to measure the voltage going into the resistor as 12 VDC coming out measured 7 VDC. This seems close to the requirement?
That’s ok.