When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
69427, based on his post, do you think the OP has 2 wires on the coil + terminal? I just have the white wire on my coil +. Looks to me the wire from the solenoid goes to the 2 wire connector for the pickup coil not the coil.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 3X2
69427, based on his post, do you think the OP has 2 wires on the coil + terminal? I just have the white wire on my coil +. Looks to me the wire from the solenoid goes to the 2 wire connector for the pickup coil not the coil.
I'll have to go look again at his posts. (My assumption was that the harness construction wouldn't make this connection a possibility.)
If the solenoid wire were to get attached to the coil + terminal I can envision several things happening.
1) The engine won't start, because the coil goes to full current and never shuts off during cranking.
2) The coil will probably fry, because there will be about 20-25 amps trying to make it's way through the primary winding (think toaster).
3) This would also (possibly) cause the module internal circuitry to backfeed current to the ignition switch if there was any voltage difference between the (higher) battery voltage at the solenoid and the (lower) voltage at the ignition switch due to wiring resistance.
You are correct regarding the solenoid wire going to the pickup coil line (The solenoid wire is actually there to shunt out the ballast wire coming from the ignition switch.)
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 69427
Is that 10v reading at the ignition switch (not good!), or at the pink wire going into the module (normal)?
You can do a simple brute force check of the module internals. Looking at the diagram that TimAT supplied, it should be the white/green wire coming off the distributor pickup wiring (or the Gray wire going into the module) that does the timing/firing signal that causes the module to shut off the coil primary current (causing the ignition coil to fire the plug). You could take a jumper wire and hook one end to the white/green wire, and with the key ON, tap (don't hold) the other end of the jumper wire to ground. Every time you tap/ground the white/green wire the coil should fire.
OP: I'm trying to help you out with your no-start issue, but it's a bit more difficult if I can't get the courtesy of a reply back from you.
Unless I'm misunderstanding your description here, I believe you mean the module +/ignition terminal.
I have the white wire from the TI harness and the wire from the starter both on the + side of the coil. I'll be home Friday night and have access to the drawings/instructions I got from "Lectric Limited" with the new harnesses, along with the wiring guides from Doc Rebuild. I'll get them posted on this thread as soon as I can.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by TimAT
I have the white wire from the TI harness and the wire from the starter both on the + side of the coil. I'll be home Friday night and have access to the drawings/instructions I got from "Lectric Limited" with the new harnesses, along with the wiring guides from Doc Rebuild. I'll get them posted on this thread as soon as I can.
Tim, the white wire to the coil + makes electrical sense to me, as that's the module/power-transistor output that supplies current to the coil (which is what your earlier posted diagram shows). The starter solenoid shunt wire in the diagram shunts the ballast resistor in the ignition feed line (which also makes sense to me). Let me know what you find on your car, as I don't see how any spark can be generated with the shunt wire at the coil+ terminal.
I used the Breakerless ignition system trouble diagnosis procedure info that 3X2 providedtroubleshooting.pdf (1.51 MB, 5 views). As I make my way through the troubleshooting, I get to the current resistance test and I read 2.57 v when checking the positive terminal of the coil to ground. It says that 0-2.5v indicates high starting by-pass resistance, high amplifier resistance or shorted coil primary. So I moved on and tested the pink wire at the 3 terminal connector (distributor connection) to ground and got 5.81v. Less than 6 v indicates resistance is too high in the starting by-pass wire. Where do I go from here?
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 1969monzared
Ok,
I used the Breakerless ignition system trouble diagnosis procedure info that 3X2 providedtroubleshooting.pdf (1.51 MB, 5 views). As I make my way through the troubleshooting, I get to the current resistance test and I read 2.57 v when checking the positive terminal of the coil to ground. It says that 0-2.5v indicates high starting by-pass resistance, high amplifier resistance or shorted coil primary. So I moved on and tested the pink wire at the 3 terminal connector (distributor connection) to ground and got 5.81v. Less than 6 v indicates resistance is too high in the starting by-pass wire. Where do I go from here?
In post #30 I asked if the 10v reading was at the ignition switch wire (white wire IIRC). Can I get an answer here?
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 1969monzared
69427,
here is is the reading at the white wire of the ti harness to the pink ignition switch wire 8.89v with key on.
Are you certain that this reading is "upstream" of the resistor in the white wire? There shouldn't be 3 1/2 volts lost between the battery and the ignition switch node that supplies power to the white wire.
battery reads 12.4v minus 3.5= 8.9v. Isn't this correct? If I unplug the ignition switch wire from the white wire the pink wire reads battery voltage. Am I giving you the answer to you question? If not explain and I'll get you the info.
In the picture I uploaded the plug is the connector between the ignition switch wire and the white wire of the ti harness. Unplugged the pink wire reads 12.4v. Plugged in it reads 8.9v. yellow wire from R terminal reads 5.87v with key on and 10.87v at crank. Pink wire from ignition switch also reads 10.9v at crank.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 1969monzared
69427,
battery reads 12.4v minus 3.5= 8.9v. Isn't this correct? If I unplug the ignition switch wire from the white wire the pink wire reads battery voltage. Am I giving you the answer to you question? If not explain and I'll get you the info.
I'm referring to the white wire at the left end that is connected to the ignition switch (in the page 2 diagram). (I forgot that Chevrolet is their "wisdom" used a white wire in two different parts of the harness.) The right side of the white wire (that connects to the pink wire) is downstream of the resistor, and that voltage reading is "unimportant" for this particular question.
Basically, I'm just trying to find out if you've got a bad/resistive connection from your ignition switch area. The coil current through the system should be somewhere in the neighborhood of 6-7 amps. If you're getting a reading across the coil (+ to ground) of 2.22 volts, you're only getting about 3 1/2 to 4 amps into the coil (that's less energy than what a points setup would deliver).
With the info you provided earlier(You can do a simple brute force check of the module internals. Looking at the diagram that TimAT supplied, it should be the white/green wire coming off the distributor pickup wiring (or the Gray wire going into the module) that does the timing/firing signal that causes the module to shut off the coil primary current (causing the ignition coil to fire the plug). You could take a jumper wire and hook one end to the white/green wire, and with the key ON, tap (don't hold) the other end of the jumper wire to ground. Every time you tap/ground the white/green wire the coil should fire.) what should I see?
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 1969monzared
69427,
With the info you provided earlier(You can do a simple brute force check of the module internals. Looking at the diagram that TimAT supplied, it should be the white/green wire coming off the distributor pickup wiring (or the Gray wire going into the module) that does the timing/firing signal that causes the module to shut off the coil primary current (causing the ignition coil to fire the plug). You could take a jumper wire and hook one end to the white/green wire, and with the key ON, tap (don't hold) the other end of the jumper wire to ground. Every time you tap/ground the white/green wire the coil should fire.) what should I see?
That is a just a quick test of the module internals. ie: the transistor circuitry that monitors the pickup coil waveform and then turns off the coil current at the appropriate time to enable the coil to generate the high voltage at the coil high tension wire. (This is done with the coil wire disconnected from the distributor and placed where it's able to spark/jump to ground for a visible check.)
Until we figure out whether the ignition power supply line is okay, I'd hold off on this test yet.
One thing that has troubled me is the plugging of something into the ignition switch connector on the interior side of the firewall. It looks like from the following diagram that a wire is run through the firewall and connected to the ignition switch panel. I just connected the wire (pink) that was initially connected to my points setup positive side of the coil to the white wire of the ti harness. Do I need to take the dash apart and run a wire through the firewall and connect the white wire of the ti harness to the ignition switch panel directly?
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 1969monzared
6947,
One thing that has troubled me is the plugging of something into the ignition switch connector on the interior side of the firewall. It looks like from the following diagram that a wire is run through the firewall and connected to the ignition switch panel. I just connected the wire (pink) that was initially connected to my points setup positive side of the coil to the white wire of the ti harness. Do I need to take the dash apart and run a wire through the firewall and connect the white wire of the ti harness to the ignition switch panel directly?
I'm interpreting that to mean that there's an additional ballast resistance in the circuit, if the wire that originally fed the points coil is now feeding the TI white wire.
I believe your right. If the wire that fed the original positive side of the coil for the points system had a resistor then it is connected to the ti harness white wire now. I did not change the wire. It reads 12.4v with the key on and disconnected from the white wire but drops to 8.9v when connected to the white wire of the ti harness.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by 1969monzared
69427,
I believe your right. If the wire that fed the original positive side of the coil for the points system had a resistor then it is connected to the ti harness white wire now. I did not change the wire. It reads 12.4v with the key on and disconnected from the white wire but drops to 8.9v when connected to the white wire of the ti harness.
Yeah, a resistor in a circuit will appear "invisible" when the wire is open circuited.
If you can get a clean ignition supply to that white wire let us know what the voltages are in the circuit, particularly the voltage across the coil (C+ to C-).
Heading out to dinner right now, I'll check in later on. Good luck.
troubleshooting.pdf (1.51 MB, 5 views). As I make my way through the troubleshooting, I get to the current resistance test and I read 2.57 v when checking the positive terminal of the coil to ground. It says that 0-2.5v indicates high starting by-pass resistance, high amplifier resistance or shorted coil primary. So I moved on and tested the pink wire at the 3 terminal connector (distributor connection) to ground and got 5.81v. Less than 6 v indicates resistance is too high in the starting by-pass wire. Where do I go from here?
