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Expert
Posts: 1316
 
Location: Belgium, 40 miles south of Brussels | Sorry if it is a dumb question, but I'm a noob at auto electrics.
My coil receives 12V from the starter switch (dark blue wire).
But the 12V is only present (measured with a voltmeter) at actual start.
Once the key and the switch go back to ignition, there's no voltage any more.
I checked the wire, it's correctly wired to the "IGN" terminal on the starter switch.
I do assume that the 12V should be present at coil at start AND ignition positions of the switch.
Correct ?
EDIT : forgot to mention I have a Pertronix Firethrower coil, a Pertronic Ignitor II module, and thus I removed the resistor before the coil.
Edited by Chrome58 2014-09-27 11:34 AM
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Expert
Posts: 3396
 
Location: Chestertown, NY ( near Lake George) | To run obviously you need 12v to the coil at all times, I assume Pertonix systems run on constant 12v, You need to pick up switched 12v from somewhere to feed the coil in the run position. |
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Expert
Posts: 2312
Location: Arizona | When you removed the resistor did you hook the two ends of the wires together? If not, that's why you have no "run" voltage. The IGN terminal only sends voltage when the starter is cranking, the circuit that goes thru the ballast resister sends current at all other times. |
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Expert
Posts: 1906
Location: Ontario, Canada | Chrome58 - 2014-09-27
I checked the wire, it's correctly wired to the "IGN" terminal on the starter switch.
I do assume that the 12V should be present at coil at start AND ignition positions of the switch.
Correct ?
Yes. If not, I would be suspicious of the switch.
Greg |
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Expert
Posts: 1316
Location: Belgium, 40 miles south of Brussels | Everything is correctly wired, I checked twice.
jimntempe - 2014-09-27 10:02 PM
When you removed the resistor did you hook the two ends of the wires together?
Yes I did.
LD3 Greg - 2014-09-28 5:58 AM
Yes. If not, I would be suspicious of the switch.
Greg
I am indeed suspicious of the switch. Although it's a NORS one, I'm beginning to wonder if it's correctly working.
I'll take it out and test it with a multimeter. |
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Expert 5K+
Posts: 8443
Location: Perth Australia | Use a test light with all the wiring still on the switch so its under load
A multimeter can tell you it still has circuit even if its bad because it does not put an electrical load on the contacts (its to sensative)
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Expert
Posts: 1906
Location: Ontario, Canada | Does the switch have screw type terminals or male tab type terminals? What year is the car? I'm just wondering if it is a later switch with both "I" 1 and "I" 2 terminals. If so, this is how "I" 2 works.
Greg |
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Expert
Posts: 2244
Location: Yorba Linda, Ca | I had to put a 1960 ignition switch in my 59 Dodge. I could not find a 59 switch.
One "ign terminal" on the 60 switch only has 12 volts in the "start position".
The other "ign terminal" only had 12 volts when in the "On position"~~~~the 12 volts would disappear when you went to the start position.
If you only hooked up ign 1 the car would start but quit as soon as you released the key from the start position.
If you hooked up the ignition to the #2 ignition the car would not start, alto it might occasionally when you released the key from the start position
or if you "just barely" turned the key to the start position.
SOooooooo~~~~ I jumpered ign 1 & ign 2 terminals of the switch together and then ran the wire to the ignition.
Problem solved!!!!! Works great and has for 4 or 5 years now!!!!
Gary |
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Expert
Posts: 1906
Location: Ontario, Canada | 1959Dodge - 2014-09-30 10:06 AM
If you only hooked up ign 1 the car would start but quit as soon as you released the key from the start position.
Gary
Gary, thanks for that info. I was not aware of that.
Greg |
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Expert
Posts: 3396
Location: Chestertown, NY ( near Lake George) | Could be wrong here it seems like that hook up would by pass the resistor and put 12v to the coil in the run position? |
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Expert
Posts: 2244
Location: Yorba Linda, Ca | I should have mentioned that I have MSD ignition on the Dodge and no ballast resistor.
But a car having a ballast resistor would run the ign terminal that has 12 volts in the start position directly to the coil,
and the other terminal that only has the 12 volts in the "Non start position" of the key to the ballast resistor, (the side of the resistor that does NOT go to the coil.
Gary |
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Expert
Posts: 3396
Location: Chestertown, NY ( near Lake George) | Correct, and understood, now. |
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Expert
Posts: 1316
Location: Belgium, 40 miles south of Brussels | To LD3 Greg : it is supposedly a correct '58 ignition switch. I have screw type terminals and they are labeled IGN, ACC, BAT and S.
Today I finally had some time to check the switch with a multimeter.
With key in driving position, I have 5 ohms between BAT and IGN (correct)
With key in start position, I have 5 ohms between BAT and IGN (correct again)
With key in accessory or off position, I have an infinite resistance between BAT and IGN (correct also).
So it seems to be correctly working.
But I keep in mind the comment from ttotired, so I will check it again tomorrow under load.
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Expert
Posts: 2312
Location: Arizona | If you are testing ONLY the switch, with your test leads connected to the actual terminals on the switch, you should be getting ZERO ohms for those readings. 5 ohms would mean the contacts are dirty and it would be like having a 5 ohm ballast resistor in the circuit. You should verify your meter really reads zero ohms when there are zero ohms by hooking the test leads together to see what it reads. I've found cheap Harbor freight meters do not read low ohms correctly often giving a reading of several ohms when the leads are directly connected together. |
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Extreme Veteran
Posts: 524
Location: West Jordan | You can test the switch with your meter, but first you need to know your meters internal resistance. No meter will show zero, my very expensive Fluke meter shows .2 ohm, and my el-cheapo Radio Shack shows 1 ohm. Set it to ohms on the lowest scale, touch red and black ( + & - ) together, the reading is your internal resistance of the meter and test leads, most resistance is usually in the test leads. With all wires connected to the switch set your meter for VOLTS not ohms, turn the key to on and attach one lead to the BAT and one to the IGN. This is called a voltage drop test and the reading is how many volts you are losing at the switch, anything more than .5 volts and you should replace the switch. Keep in mind your meters internal resistance and factor that into your reading, however anything more than 1 volt and I would replace the switch. Also with the key on do the same voltage drop test from the IGN to the + terminal of the coil. This will tell you if you have resistance in the wire, but if you need to use a jumper wire it will add resistance unless you use a 10 gauge wire, you should test its voltage drop off the battery so you can factor that in. I have seen switches that don’t quite spring back to run, they get stuck in between, try starting it and quickly moving the key to IGN from S or try moving the key around as you are testing for voltage. |
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Expert
Posts: 2312
Location: Arizona | My good meters will show a very small resistance, perhaps 0.1 ohm if set to autorange. If set to a fixed range they show zero ohms if the test leads are directly connected. The free HF meter shows 1.8 ohms on the 200 ohm range. This is not a measure of the meters internal resistance. The internal resistance of a good meter will be thousands of ohms. http://www.allaboutcircuits.com/vol_1/chpt_8/6.html |
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Expert
Posts: 1316
Location: Belgium, 40 miles south of Brussels | Thanks to everyone.
I checked the ignition switch under 12V load and it was faulty.
Bought a new one.
Thanks. |
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12V at coil only at start
