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| minimum coil voltage https://slantsix.org/forum/viewtopic.php?t=58410 |
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| Author: | waunan [ Fri Sep 25, 2015 8:32 am ] |
| Post subject: | minimum coil voltage |
trying to diagnose a no spark issue on 225 previous coil and ballast resistor with 12.6 battery volts into ballast resistor 8.5 out was 4.5 to coil new coil and ballast resistor in 11.1 and out 8.5 to coil getting 8.5 volts from negative side of coil to distibutor ground could not find info in my tech manual on this still not a hint of spark coming out of coil nor plug new coil and ballast resistor spec out for resistance any ideas from the gurus? if this is somewhere else i could not find it here naturally i apologize if i missed it |
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| Author: | emsvitil [ Fri Sep 25, 2015 11:39 pm ] |
| Post subject: | |
electronic or points? |
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| Author: | waunan [ Sat Sep 26, 2015 8:09 am ] |
| Post subject: | points |
it turns out I cooked the points from a miswire  so new points and condensor and it now purrs like a kitten with 8.5 volts at coil I have a feeling it would have run with 4.5 and would still love to hear from the gurus on minimum/ ideal voltage it makes sense that it will will be way lower once it starts as ballast heats up |
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| Author: | Old6rodder [ Sat Sep 26, 2015 9:20 am ] |
| Post subject: | |
That's one of the three main reasons I still run points, they'll fire on half the battery's voltage in a pinch. The others're that they're field fixable, and that they very seldom go bad without plenty of warning. |
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| Author: | Sam Powell [ Wed Sep 30, 2015 5:46 am ] |
| Post subject: | |
Quote: That's one of the three main reasons I still run points, they'll fire on half the battery's voltage in a pinch. The others're that they're field fixable, and that they very seldom go bad without plenty of warning.
Yep. If voltage drops, electronic ignitions fall off a cliff. When I switched to electronic ignition 20 years the mileage went in the toilet. What? Turns out pretty much everthing in the wiring and charging system was below standard, which had little effect on the points ignition. This led to a massive upgrade and replcement project. If you had an electronic ignition, I think 11.1 volts would represent some compromise in performance. 12.5 is better. That drop between the alternator, which would be 13 or better typically, is the result of corrosion and crud in all the spade connectors and crimp joints between the alt and the ballast resister. It was Dan Stern who led me to run a pair of fused wires from the alt output to a bus on the pass fender, where all power for the rest of the car is tapped from. A volt meter replaced the ameter so that is no longer in series in the ignition circuit. Gone also are the critical ignition connections that used to run through the bulkhead connector. Sam |
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| Author: | curmudgeon [ Wed Sep 30, 2015 8:24 am ] |
| Post subject: | |
to run a pair of fused wires from the alt output to a bus on the pass fender, where all power for the rest of the car is tapped from. A volt meter replaced the ameter so that is no longer in series in the ignition circuit. Gone also are the critical ignition connections that used to run through the bulkhead connector. Could you please provide some more specifics? Like what gauge wires, fused wire size, and to Dan, why fused wire instead of inline fuses? I really like this idea but when it comes to electrics, unless I have a specific step 1, step 2, etc, I definitely wear the coned dunce cap. Thanks. Fred |
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| Author: | Sam Powell [ Wed Sep 30, 2015 7:13 pm ] |
| Post subject: | |
Sorry to imply wires are fusible links. They have standard spade fuses.I will look at my set up soon and get back to you. In the mean time, Dan may chime in with details. Sam |
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| Author: | waunan [ Sat Oct 03, 2015 9:01 am ] |
| Post subject: | Voltmeter vs ammeter |
thanks for the responses Sam...are you saying there is an ammeter in the stock set up? Definitely confused why this would be the case though I can understand why it could work as current drops as battery charges. |
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| Author: | Sam Powell [ Sat Oct 03, 2015 7:34 pm ] |
| Post subject: | |
The ameter in the dash is in series with pretty much everything except the starter motor. When they get old they can be a source of high resistance. The nut that hold the wires on the back can get loose also resulting in more resistance, and more voltage drop. Tomorrow I will take a look at my wiring and give you a detailed description of how the power is routed. Sam |
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| Author: | Sam Powell [ Mon Oct 05, 2015 7:59 pm ] |
| Post subject: | |
Waunan, here is a verbal description of how my power is routed under the hood: 1. Two # ten wires come off the alternator feed to a pair of 60 amp fuses the are in parallel. They are side by side. 2. Two # ten wires run in parallel from the other connector on each of those fuses, and travels to the front of the radiator core support, across to the driver's fender where they are fastened together to a stud on very heavy brass bus bar with 4 large studs on it. 3. A # ten wire goes from another stud on the 12+ bus to the battery positive terminal. 4. A # 10 wire goes from the bus bar to the stud on the starter relay that has the fusible link into the bulkhead connector. Both wires are now on the same stud. 5. A # 12 goes from the bus to a fuse box on the fender that is switched by a relay. 6. A # 10 goes from the 12+ bus to an unswitched fuse box on the fender. These last two power accessories I have added such as electric fans and fuel injection. Since my battery is in the trunk, the wire from the bus bar to the battery simply goes to the starter motor on the 12+ side, since that has the positive batter cable running to it. If you do this, you will bi-pass the ammeter, and it will no longer give you a meaningful reading. You will want to put a volt meter under the dash somewhere. This will eliminate all of the high resistance connections in the system. As an important warning, I have a GM alternator, which has no external regulator. Someone else will have to tell you how it gets handled in this system. I think its reference wire can hook to the bus, but this may be an error, so lets get feedback from one of the smart guys here. Sam |
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| Author: | waunan [ Wed Oct 07, 2015 11:09 am ] |
| Post subject: | Voltmeter alternative |
Sam thanks for taking the time to describe your electronics. 60 amps is a lot of current...I trust you are happy with the performance and that the mileage has improved since the changes I plan on getting a voltmeter soon after running the car for awhile to assess any changes with ammeter out of the picture. Will post voltage to coil with/without ammeter and any noticeable changes with power/mileage here. Thanks again to all who have responded. |
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| Author: | Sam Powell [ Fri Oct 09, 2015 7:58 am ] |
| Post subject: | |
Mileage jumped from 13 to 18 with the stock engine (with electronic ignition aleady applied) when I made this change. The MSD and two barrel raised it to 21 mixed suburban driving. The OD four speed swap from a 904 raised it to 25. My current engine was designed for turbo, but is now NA and never achieved the highs the stock engine reached. I honestly do not drive it enough now to get a good baseline established. Sam |
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| Author: | curmudgeon [ Thu Oct 15, 2015 7:15 pm ] |
| Post subject: | |
Sam, I know I'm real late in saying this but thanks a bunch for describing your wiring. Lots going on in my life that has kept me going in multiple directions at the same time. Fred |
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