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Dave Fiedler of T.I. Specialties is an expert at the K66Factory Transistorized Ignition system. He has been working with them since the early 1980's and knows just how they fail and "why". The amplifier board inside the little case on the inside of the front left fender can also fail randomly as can the Ignition coil.
I had my Dave of T.I.Specialties rebuild my distributor and help me get the parts working together the best way possible. He replaced the amplifier board with a more recently designed unit which is more robust than the original unit was and that is a good thing. My original board was returned with the parts as it was still functional.
If the unit failed and blew a fuse or anything then I would also check the source of power and even the fusible links in the area of the left front fender. Being a Corvette means you always check for a good ground at the component. Bad grounds are just as big a problem on 50+ year old engines.
69427: You might want to re-check the electrical circuit diagram. "S" is the connection to the ignition switch START contact. "R" is the power feed to the coil (in a points system) or to the TI module for the electronic system.
69427: You might want to re-check the electrical circuit diagram. "S" is the connection to the ignition switch START contact. "R" is the power feed to the coil (in a points system) or to the TI module for the electronic system.
R is only active while cranking since it gets power from S. Once started the ignition switch provides power.
69427: You might want to re-check the electrical circuit diagram. "S" is the connection to the ignition switch START contact. "R" is the power feed to the coil (in a points system) or to the TI module for the electronic system.
You don't understand the circuit and you don't know 69427 or you would not have questioned his post. Check the ignition sticky on this forum.
I'm assuming you weren't getting any spark directly out of the coil while cranking? Try disconnecting the lead to the positive coil terminal to see if you have voltage at that terminal while disconnected. Also, have you checked ignition coil resistance?
You don't understand the circuit and you don't know 69427 or you would not have questioned his post. Check the ignition sticky on this forum.
Took your advice and read through the whole ignition sticky. Nary a mention of the starter solenoid current flows so no info there.
That said, most of the GM material shows the "R" and "S" terminals at 3 and 9 o'clock
respectively while replacement units will show their positions swapped so be careful if you get a new one.
I'm assuming you weren't getting any spark directly out of the coil while cranking? Try disconnecting the lead to the positive coil terminal to see if you have voltage at that terminal while disconnected. Also, have you checked ignition coil resistance?
I had no voltage, or so I thought at the coil. I got under the car last night. No easy feat with a jack and jack stands. Starter looks original while the solenoid does not.
I confirmed switched 12V at the "S" terminal. (9 O'clock on my solenoid) There is a heat shield protecting the solenoid so getting a lead onto the "R" terminal
was a challenge and could only be "confirmed" by feel not by sight. I read 6-7 V at the coil *[edit, from the solenoid R contact, NOT the coil] from this lead while cranking. It should be more.
Coil pretty much Ohms well .5 primary. though a bit high @13.2K secondary.
As they say, "When you hear hoofbeats think horses not zebras." Pulling the coil lead I found this!
Coil side of lead was burned and disintegrated.
I am not familiar with this types of wires but the lead seems to be graphite impregnated braided line and no metallic material.? On the coil side it was totally frayed
and turned to dust inside the connection. could explain why the car has 6 Accel plug wires and 2 run of the mill plug leads.
I Will dig up a spare coil lead next day or 2 and retry. Stay tuned.
I think you found the issue. That deterioration was due to a poor crimp. I would stick with the supression wires, which the newer ones have a silicone core which eliminate radio static and last a very long time. Whenever I check a car for a no start, the coil wire is the first thing I check with also testing for spark out of the coil. Good job!
BTW, I would check the terminals for all of the wires since it appears that they were cut and crimped, so they all may be crimped poorly.
Dave Fiedler of T.I. Specialties is an expert at the K66Factory Transistorized Ignition system. He has been working with them since the early 1980's and knows just how they fail and "why". The amplifier board inside the little case on the inside of the front left fender can also fail randomly as can the Ignition coil.
I had my Dave of T.I.Specialties rebuild my distributor and help me get the parts working together the best way possible. He replaced the amplifier board with a more recently designed unit which is more robust than the original unit was and that is a good thing. My original board was returned with the parts as it was still functional.
If the unit failed and blew a fuse or anything then I would also check the source of power and even the fusible links in the area of the left front fender. Being a Corvette means you always check for a good ground at the component. Bad grounds are just as big a problem on 50+ year old engines.
After replacing a beyond dodgy coil lead with no luck, signs now pointing to the K66 system amplifier. Coil specs fine, output from starter solenoid OK, no volts to coil which gets it's feed from the amplifier. (fusible links seem intact) Time to pull it out and see what's up.
After replacing a beyond dodgy coil lead with no luck, signs now pointing to the K66 system amplifier. Coil specs fine, output from starter solenoid OK, no volts to coil which gets it's feed from the amplifier. (fusible links seem intact) Time to pull it out and see what's up.
I'd bet that arcing coil wire took out the module.
Now that your suspect is the TI Amp, you can use a HEI module in place of the TI Amp to test that theory. Bypass the AMP and all it's wiring. Wire as per the diagram, if it starts and runs, then you know that the pickup in the dist & ign coil are good.
For extended testing, the HEI module needs to be attached to an aluminum heat sink, or just a piece of aluminum. (To keep it cool)
This setup does NOT require any starter wiring connection.
Mystery solved. It both was, and was not (only) the amp. When I did the timing gear install last month i removed the radiator for inspection and cleaning.
On reinstall I severely pinched the TI amp harness between the shroud and a sharp bit and pierced the amp harness.
(Does anyone know how to "easily" remove the LT plastic rad shroud as i likely have to go back in?!)
Fixing the pierced wire and swapping out the shot coil lead and the car fired right up though a little lumpy. Will procure a new reliable wire set and hopefully this particular drama is put to bed.
I found the pinched wire as i was looking for ways to extricate the amp. That looks like one miserable job as there is no way to get hand and wrench in there while seeing
what you're doing and the through bolts to the fender well are as rusted as you might think after 50+ years.
I had already ordered an HEI module to test the rest of the system so I will pre-wire it and have iit ready to splice in if/when the TI amp fails.
Thx all for the help.
Originally Posted by Barry's70LT1
Now that your suspect is the TI Amp, you can use a HEI module in place of the TI Amp to test that theory. Bypass the AMP and all it's wiring. Wire as per the diagram, if it starts and runs, then you know that the pickup in the dist & ign coil are good.
For extended testing, the HEI module needs to be attached to an aluminum heat sink, or just a piece of aluminum. (To keep it cool)
This setup does NOT require any starter wiring connection.
Just a thought, on the harness where you made the repair, use waterproof/marine heat shrink tubing. It is self sealing, and you won't have any moisture intrusion. Good luck!
Mystery solved. It both was, and was not (only) the amp. When I did the timing gear install last month i removed the radiator for inspection and cleaning.
On reinstall I severely pinched the TI amp harness between the shroud and a sharp bit and pierced the amp harness.
(Does anyone know how to "easily" remove the LT plastic rad shroud as i likely have to go back in?!)
Fixing the pierced wire and swapping out the shot coil lead and the car fired right up though a little lumpy. Will procure a new reliable wire set and hopefully this particular drama is put to bed.
I found the pinched wire as i was looking for ways to extricate the amp. That looks like one miserable job as there is no way to get hand and wrench in there while seeing
what you're doing and the through bolts to the fender well are as rusted as you might think after 50+ years.
I had already ordered an HEI module to test the rest of the system so I will pre-wire it and have iit ready to splice in if/when the TI amp fails.
Thx all for the help.
Why not get an updated amplifier from TI Specialties?
Mystery solved. It both was, and was not (only) the amp. When I did the timing gear install last month i removed the radiator for inspection and cleaning.
On reinstall I severely pinched the TI amp harness between the shroud and a sharp bit and pierced the amp harness.
(Does anyone know how to "easily" remove the LT plastic rad shroud as i likely have to go back in?!)
Fixing the pierced wire and swapping out the shot coil lead and the car fired right up though a little lumpy. Will procure a new reliable wire set and hopefully this particular drama is put to bed.
I found the pinched wire as i was looking for ways to extricate the amp. That looks like one miserable job as there is no way to get hand and wrench in there while seeing
what you're doing and the through bolts to the fender well are as rusted as you might think after 50+ years.
I had already ordered an HEI module to test the rest of the system so I will pre-wire it and have iit ready to splice in if/when the TI amp fails.
Thx all for the help.
Not for nothing, but if you make this HEI setup, I would test it before you need it just to make sure the module is functional.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by fstntq
Took your advice and read through the whole ignition sticky. Nary a mention of the starter solenoid current flows so no info there.
That said, most of the GM material shows the "R" and "S" terminals at 3 and 9 o'clock
respectively while replacement units will show their positions swapped so be careful if you get a new one.
I'll take some time this weekend and add some TI specific information to the Ignition Sticky. The sticky was originally focused on the design and physics of ignitions (my vocation), but there's some important differences in how the TI system is wired and operates compared to Points systems, so some troubleshooting info may be helpful in that section. (I'll discuss the reason for the starter solenoid R terminal as well.)
