1973 Corvette Ignition problems
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1973 Corvette Ignition problems
I have recently completed the project of replacing the shifter on my 73' and I went for the first drive with everything installed and everything went perfect until I reached a stop light and the car lost power. Then the car wouldn't start. We then pushed it into a parking lot and started to try to get it to start to get it home. We found out that it had lost spark. On top of this, the turn signals had stopped working while all other electrics in the car still worked. So I then started tracing through the wiring to see if something had just come unplugged (I have HEI that is wired through the IGN port on the fuse box) and everything was still fine and plugged in. Then on one of my attempts to start the car, it finally started. But it started when I let the key off from start to Run. When I got the car home I found that the IGN port wasn't giving power at all. When in the start position with the starter running there were 0 volts but then 12 when returned to the run position. What could cause this? Is it the IGN switch? Why did the turn Signals go out at the same time?
Last edited by Logan B; Sep 18, 2022 at 07:21 PM.
Safety Car
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From: Corpus Christi, TX
For old fashioned points ignition, the coil gets power from the starter solenoid when the key is in the START position. Your tap on the IGN port, if memory serves right, is hot only in the ON position, which is what you measured. You may need to rig up an extra wire to the I terminal on the starter solenoid to get ignition power during cranking
Your turn signals must be on the same circuit. Anything that works when in the ON position but not ACC will do the same thing. Everything on ACC should work during cranking. In the FWIW department, my turn signals work on ACC. Didn't think to check them during cranking
Your turn signals must be on the same circuit. Anything that works when in the ON position but not ACC will do the same thing. Everything on ACC should work during cranking. In the FWIW department, my turn signals work on ACC. Didn't think to check them during cranking
Thread Starter
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For old fashioned points ignition, the coil gets power from the starter solenoid when the key is in the START position. Your tap on the IGN port, if memory serves right, is hot only in the ON position, which is what you measured. You may need to rig up an extra wire to the I terminal on the starter solenoid to get ignition power during cranking
Your turn signals must be on the same circuit. Anything that works when in the ON position but not ACC will do the same thing. Everything on ACC should work during cranking. In the FWIW department, my turn signals work on ACC. Didn't think to check them during cranking
Your turn signals must be on the same circuit. Anything that works when in the ON position but not ACC will do the same thing. Everything on ACC should work during cranking. In the FWIW department, my turn signals work on ACC. Didn't think to check them during cranking
Team Owner
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From: altered state
St. Jude Donor '05
Will be following this...my Camino started doing the same thing every wire/nut/componenet was brand new
Replaced ign switch to no avail, stumped. Didnt die but a betch to start.
Replaced ign switch to no avail, stumped. Didnt die but a betch to start.
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2025 c3 ('74-'82) of the Year Finalist - Unmodified
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Race Director
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i am pretty sure ignition does not shut off in crank. blowing the I fuse you need to chase down the short. we are not there. first unplug wire at distributor. see if fuse pops. then start working backwards from there. and keep a hunk of wire long enough to hot-wire ignition to the alternator stud with you in the car. then it will never fail again.
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You mentioned that you’ve been driving this for 8 months without any issues until now.
It sounds like you may have either a short that developed because of a loose, pinched or burned wire or some component has recently failed.
I would first check each wire throughout your ignition system, especially the wires at the starter to make sure everything is torqued and nothing is shorting.
Then start checking each component to make sure nothing has failed.
Have you made any recent changes or upgrades anywhere else on the car?
Even any non ignition related changes?
If you find nothing in the ignition circuit, you may also need to look at the turn signal circuits and check those wires and components as well, since they seem to be related.
It sounds like you may have either a short that developed because of a loose, pinched or burned wire or some component has recently failed.
I would first check each wire throughout your ignition system, especially the wires at the starter to make sure everything is torqued and nothing is shorting.
Then start checking each component to make sure nothing has failed.
Have you made any recent changes or upgrades anywhere else on the car?
Even any non ignition related changes?
If you find nothing in the ignition circuit, you may also need to look at the turn signal circuits and check those wires and components as well, since they seem to be related.
Last edited by OldCarBum; Sep 18, 2022 at 02:07 PM.
Le Mans Master
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Does it crank (turn over)? If not then looking at the wiring you disturbed when playing with the shifter. Is it an automatic? If so, then you might have messed with the Neutral/Park Safety Settings if you changed the shifter...... hell, you may have done that even with a manual.
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Does it crank (turn over)? If not then looking at the wiring you disturbed when playing with the shifter. Is it an automatic? If so, then you might have messed with the Neutral/Park Safety Settings if you changed the shifter...... hell, you may have done that even with a manual.
You may have pinched a wire when working on the shifter, or mis wired something.
Last edited by OldCarBum; Sep 18, 2022 at 02:22 PM.
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Is this how you have it permanently wired or did you do this as a bypass to check something after your ignition failed?
Did you use the oem pink resistance wire to wire the new HEI or did you run an new dedicated wire to the fuse box?
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Does it crank (turn over)? If not then looking at the wiring you disturbed when playing with the shifter. Is it an automatic? If so, then you might have messed with the Neutral/Park Safety Settings if you changed the shifter...... hell, you may have done that even with a manual.
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But even the best and newest coils can fail without warning.
Is this how you have it permanently wired or did you do this as a bypass to check something after your ignition failed?
Did you use the oem pink resistance wire to wire the new HEI or did you run an new dedicated wire to the fuse box?
Is this how you have it permanently wired or did you do this as a bypass to check something after your ignition failed?
Did you use the oem pink resistance wire to wire the new HEI or did you run an new dedicated wire to the fuse box?
Thread Starter
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