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Discussion Starter · #1 ·
I have a 67 with 396 4 spd that last year I had reversed the battery cables and had to replace starter wires, and coil wires. Ever since then it has been running rough. I had it tuned by a mechanic, and it ran like new for a week, then back to rough. Today, I unplugged the harness plug that goes into the firewall to the coil/brake sensor and other things, to see how hard it would be to replace the wires from the plug, but after looking at it, I plugged it back in. I also notice that the starter wires and become crispy again from touching the headers, so I replaced the one that goes to the coil from the soleniod, but the other one looks ok. Now the car wont start. It sounds like it it starting as soon as you touch the key, but it doesnt (even though when it is running, it takes a couple of seconds of turning the key to start it.) I know it is in the electrical, but I am stumped.
 

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66 El Camino 57 Chevy pickup 2004 Tahoe
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that wire that runs from the starter to the coil, check it to make sure it's good. it goes on the outside small post on the solenoid, feed power to the coil during cranking. it goes to the + side of the coil. if in doubt run a new wire between those two points.

It's been discussed here, IIRC the ignition switch on 66/67 does not feed power to the coil during cranking. Seems weird but that's the way it is.
 

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As Tom said, when in the "start" mode on the ignition switch power goes to the solenoid but is interrupted to the coil. This is replaced with power from the solenoid directly to the coil. This is done to allow full 12 volts to the coil rather than the reduced (9 volts) that goes to the coil in the run mode. The reason is to boost cranking power to the coil then dropping it after it starts and you return the switch from start to run. Most stock type coils want to see 9 volts during normal operation (don't ask me why). Check to be sure you haven't inadvertently connected something wrong. What you should have is one wire to the + side of the coil from the resistor or ignition switch and another, also on the same terminal from the solenoid (sorry I can't remember which is which on the solenoid...one is the power from the ignition switch to make it engage, the other is the one going to the coil....you can easily figure this out with a simple test light). Here's another test. Make yourself a jumper wire directly from the battery to the + terminal on the coil and it should fire right up. If it does we've identified your problem. You'll have to pull the wire off to shut off the motor. Did this many times as a teenager when we "borrowed" someones mom's car for a Saturday night joy ride!!! Between that and a screw driver across the start solenoid you didn't need a key! If all this doesn't provide an answer pull a plug wire and stick a phillips screwdriver in it, hold it close to the block and have someone crank it over. Do you have spark?? If not you'll need to look at the cap, rotor, wire from the - terminal on the coil to the distributor, points, etc.
 

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Discussion Starter · #4 ·
I ran a jumper from battery to + side, and it did start right up, Does that mean the new wire i ran from solenoid to + side coil is bad?
 

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It probably means the firewall connector you took apart needs to come apart again. Disconnect the battery, disconnect the connector, and inspect all of the connections inside. Chances are, you'll find a couple that look like they've gotten hot, or they're bent so they can't make good contact. Clean them up with a wire brush, fine sandpaper, etc., until they're shiny, then bend the contacts carefully so they'll make strong contact with the opposing contacts in the fuse box. Put it back together carefully and give it a try.
 

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Discussion Starter · #6 ·
Is that connector available after market, or do you have to buy a large wiring kit?
 

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Discussion Starter · #7 ·
I took the connector apart, hit them with a wire brush, slightly bent the connectors, and still wont start. The inside of the connectors looks pretty good, its the outside where the wire enter that looks like a pound of goo. Is that connector with wires available after market? I cant find it.
 

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66 El Camino 57 Chevy pickup 2004 Tahoe
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if that connector and the terminals inside it look OK they probably are OK. I'd go back to that wire that runs from the solenoid to the coil +. use a test light or volt meter to check if it has battery voltage while the starter is cranking.

Do you have an HEI or what ignition do you have?
 

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Discussion Starter · #10 ·
test light on the coil shows juice in start position, not in run. Thats why is sounds like it started until I move the key to run.
 

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That is the typical symptom of a burned out ballast resistor. It will start and then die in the run position. That is why it ran when you bypassed it with your jumper wire. As other's have said, the voltage through the ballast resistor is bypassed in the start position. In the run position it goes through the ballast resistor to limit current to the coil and points. Your Chevelle doesn't use a typical ballest resistor but uses a resistance wire, You'll need to trace back from the coil + terminal towards the ignition switch until you see voltage. You can do this with a test light or voltmeter with the key in the run position or with the power off using a ohmmeter to check for continuity. It could be the ballast resistance wire or any wire or connection between the switch and the coil. Or I suppose even the ignition switch. It shouldn't be to hard to find. Good luck.
 

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the resistance wire is a yellow cloth covered wire, looks different from any other wire on the car. you should be able to see the cloth covered wire at the coil and where the wires come out of the loom at the bulkhead connector. there should be continuity on the wire but resistance when checked with an Ohmeter.

quick fix: run a new wire from the IGN terminal in the fusebox out the the firewall near the coil. buy a ballast resistor, run the wire to it. run another wire from the other side of the ballast to the + side of the coil. Unless you have something bad wrong with the ignition switch this will get you up and running.

Actually, there might well be something wrong with the ignition switch.
 

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Discussion Starter · #13 ·
I doubt its in the ignition switch since my problem started with me unplugging the bulkhead harness to see how hard it would be to replace that resistor wire because I have been wary of it since it started smoking badly last year when I had similar problems. I am going to the zyphrehills swap meet tomorrow, and I am considering picking up an hei distibutor so I can do away with this wire.
 

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Discussion Starter · #14 ·
If I dont get an hei, I am probably going to run the wire and new resister like you said though.
 

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As Tom said, when in the "start" mode on the ignition switch power goes to the solenoid but is interrupted to the coil. This is replaced with power from the solenoid directly to the coil. This is done to allow full 12 volts to the coil rather than the reduced (9 volts) that goes to the coil in the run mode. The reason is to boost cranking power to the coil then dropping it after it starts and you return the switch from start to run. Most stock type coils want to see 9 volts during normal operation (don't ask me why). Check to be sure you haven't inadvertently connected something wrong. What you should have is one wire to the + side of the coil from the resistor or ignition switch and another, also on the same terminal from the solenoid (sorry I can't remember which is which on the solenoid...one is the power from the ignition switch to make it engage, the other is the one going to the coil....you can easily figure this out with a simple test light). Here's another test. Make yourself a jumper wire directly from the battery to the + terminal on the coil and it should fire right up. If it does we've identified your problem. You'll have to pull the wire off to shut off the motor. Did this many times as a teenager when we "borrowed" someones mom's car for a Saturday night joy ride!!! Between that and a screw driver across the start solenoid you didn't need a key! If all this doesn't provide an answer pull a plug wire and stick a phillips screwdriver in it, hold it close to the block and have someone crank it over. Do you have spark?? If not you'll need to look at the cap, rotor, wire from the - terminal on the coil to the distributor, points, etc.
All coils run off of 12 volts (whether cranking or in RUN mode). That's the vehicle system voltage (battery and alternator) and is the voltage at the coil at the start of every dwell. The ballast resistor is there to limit the current (that 12 volts is trying to push) to prevent frying the points or coil. Twelve volts doesn't hurt anything, but excess current does. Using a voltmeter to measure a PWM inductive-resistive switching circuit will not give you any accurate indication of what's going on. (It's similar to telling someone your car did the 1/4 mile in 12 seconds, and he concludes that your car ran a steady 75 mph on the track. We all know that's not correct. Seventy five is just the average, and your car was actually at 75 mph for only an instant. The real story is much different than the calculated average.)

CKN1234 was correct in his description. :thumbsup:
 

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So the resistor wire from the bulkhead to the Coil only allows 9 volts? and then back from the R terminal is 12? Reason I'm asking is I've got HEI in mine and cleaned up my wiring but ran a new 12gauge wire from ign. fuse block to dist hot. I was going to use the original resistor wire to power up my fuel pump. I"m guessing that will not work if its only allowing 9volts. I'm guessing thats stupid idea, I'm gonna take a voltage check at the end and see what i've got.
 

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So the resistor wire from the bulkhead to the Coil only allows 9 volts? No. and then back from the R terminal is 12? Reason I'm asking is I've got HEI in mine and cleaned up my wiring but ran a new 12gauge wire from ign. fuse block to dist hot. I was going to use the original resistor wire to power up my fuel pump. I"m guessing that will not work if its only allowing 9volts. I'm guessing thats stupid idea, I'm gonna take a voltage check at the end and see what i've got.
The ballast/resistance wire is a resistor. It is NOT a voltage regulator. As I mentioned earlier it's purpose is to limit the current. If you put a voltmeter on the ballast line you will get a hundred different readings depending on what you hooked to it. If the points are open you will get 12 volts. If the points are closed you will get 6-8 volts normally. If you connect a high resistance relay winding you might get 10 volts. The point is that the ballast is a resistance in the line to limit the current, and not a voltage regulator to setup some "desired" voltage.
 

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Discussion Starter · #19 ·
Put it in today, and it started right up. Still running a little rough under heavy load, but much better. Thanks guys.
 
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