New 74 Project Won't Start
Thread Starter
Cruising
Joined: Jul 2015
Posts: 12
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Just to follow-up, need to get a new voltmeter since my old one doesn't seem to be working. I'll test the purple/wht wire to see if it has 12 volts. If it doesn't, what would that indicate? Also, any idea where that connector in my first pic (purple/wht & green/blk wires) connects to? It's not long enough to go anywhere beyond the steering column area. I'm not sure if that's the key to getting the car to start, but it should control something since it runs from ignition to interlock under the hood, then NSS.
If I can't get this figured out, it's going back on Craigslist. This a little beyond my expertise.
If I can't get this figured out, it's going back on Craigslist. This a little beyond my expertise.
Thread Starter
Cruising
Joined: Jul 2015
Posts: 12
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Update!!
Had a chance to test some things with a voltmeter last night. I have 11 volts at the battery, 11 volts at the starter, nothing at the ignition coil. With the key on, I don't get any volt reading between the + and - terminals on the coil.
There is one small wire going from starter to ignition coil + terminal. Is that my culprit? Or would there be another issue? Feel like I'm getting a little closer.
There is one small wire going from starter to ignition coil + terminal. Is that my culprit? Or would there be another issue? Feel like I'm getting a little closer.
Le Mans Master
Joined: Aug 2006
Posts: 7,427
Likes: 1,560
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
The battery should show at least 12 + volts so recharge it.
At the starter you have two small wires.
Turning the key to START sends 12 volts to the NSS and the NSS switch sends it to the inside wire (closest to the block) on the starter solenoid (the purple wire).
The YELLOW wire on the outside of the solenoid ( closest to the fender) sends 12 volts to the + side of the coil only while the starter is turned ON.
See the diagram at post 7.
With the key in RUN the + wire on the coil will have 12 volts.
Test from the + side of the coil to a ground, not from + to - on the coil.
At the starter you have two small wires.
Turning the key to START sends 12 volts to the NSS and the NSS switch sends it to the inside wire (closest to the block) on the starter solenoid (the purple wire).
The YELLOW wire on the outside of the solenoid ( closest to the fender) sends 12 volts to the + side of the coil only while the starter is turned ON.
See the diagram at post 7.
With the key in RUN the + wire on the coil will have 12 volts.
Test from the + side of the coil to a ground, not from + to - on the coil.
Thread Starter
Cruising
Joined: Jul 2015
Posts: 12
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I'll check that this weekend. Also going to look again at the two-wire plug in my first pic. It contains the purple/wht and green/blk wires, and needs to be connected somewhere under the dash. Should be the same green/blk wire from the NSS so my guess is the circuit is not complete.
Is there only one connector plugging into the ignition switch? I may take that off the column to see if it's working correctly, or if I have everything plugged in. I can turn the ignition on without the key, so the tumbler has an issue, but maybe the switch itself is partially bad. I get two interior lights on with the ignition on, but no other dash lights, buzzer, or starter action.
Is there only one connector plugging into the ignition switch? I may take that off the column to see if it's working correctly, or if I have everything plugged in. I can turn the ignition on without the key, so the tumbler has an issue, but maybe the switch itself is partially bad. I get two interior lights on with the ignition on, but no other dash lights, buzzer, or starter action.
Thread Starter
Cruising
Joined: Jul 2015
Posts: 12
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Update
Checked he yellow wire on the coil to a ground and I have 12 volts. I also found a connector in the interior that had the purple/wht and green/blk wires clipped. I re-connected those and used a jump wire between them...and pow, car cranks when turning the key. However, no fire.
Looks like I'm not getting fuel to the carb. Previous owner bought new gas tank and sending unit, so I installed those. Not sure if the fuel pump is working or not. I assume those are mechanical and pump fuel only when engine is cranking? There is a see-through fuel filter installed between the pump and carb and can tell there is no fuel getting past there. Does that indicate a bad pump?
Last edited by Cjf5150; Jul 20, 2015 at 10:44 AM.
Le Mans Master
Joined: Aug 2006
Posts: 7,427
Likes: 1,560
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Good! Your making progress.
With a fire extinguisher handy remove the fuel line that attaches to the carb and run a rubber line to a container and crank the engine, you should get about a pint of fuel in about 30 seconds.
Next bypass the fuel filter to see if it is clogged.
If not then check the rubber hose between the hard fuel line and the fuel pump, it may be kinked if the PO used a non molded hose.
https://willcoxcorvette.com/corvette...it-front-70-82
If you have fuel in the tank and all the above is good then the fuel pump may be bad.
Next bypass the fuel filter to see if it is clogged.
If not then check the rubber hose between the hard fuel line and the fuel pump, it may be kinked if the PO used a non molded hose.
https://willcoxcorvette.com/corvette...it-front-70-82
If you have fuel in the tank and all the above is good then the fuel pump may be bad.
1st Gear
Joined: Sep 2017
Posts: 1
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From: Raleigh NC
I'm having the same issue with my 74 not starting
I'm having the same issue with my 1974. Wondering if you ever figured this out? I actually live in Raleigh too (not sure if you do still). Anyway would love any guidance.
