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Bikespace, I get the jest of the test and flow but not sure what you mean by put the resistance wire in series with the coil? This is a finished car and not sure how to access the end of the resistance wire. I’m assuming it terminates somewhere around the fuse block? I’m not sure how I could apply voltage or do you just mean turn the ignition on?
KC
Yes, IGN ON will work. If you don't know where the resistance wire gets its power. If you do, be sure to measure the voltage there as well.
You should have battery voltage (or close to it), in your fuse panel. But part of what we are debugging is looking for shorts or resistances.
Yes, IGN ON will work. If you don't know where the resistance wire gets its power. If you do, be sure to measure the voltage there as well.
You should have battery voltage (or close to it), in your fuse panel. But part of what we are debugging is looking for shorts or resistances.
Thanks for clarifying, I’ll be out with travel but will report back. It’s seems like this issue is narrowing down to the resistance wire not providing resistance?
KC
Jebby, if I miss “spoke” somewhere in the thread……I do have it wired as you described. I’ve got this narrowed down to close to full battery voltage thru my resistance wire into the plus side of the coil. I’m traveling for work but my plan is to check the resistance on the factory “resistance wire” from the fuse block or ignition to the plus side of the coil.
KC
I’m currently checking my resistance wire that goes to the plus side of the coil. Does it terminate at the fuse block or at this connection on the steering column? I’m trying to find the end so I can check the wire resistance. It’s a tough area to work in!
KC
It goes from the ignition switch to the fuse block as a normal wire. It turns into the resistance wire on the engine side of the fuse block, with a color change.
I think that connector you show is for the horn and turn signal stuff.
The ignition switch itself looks like this: And has a large rectangular type connector:
And is located in a very difficult to reach spot on the column:
You are looking for the two purple wires shown in post 229
There is a long rod that goes from the switch on the lower column, up to the key. The key moves the rod, which goes into the switch, and engages the correct terminals in the switch. Look at the switch above, the mounting screws have slots to allow for correct adjustment. Yours could have an issue with the correct wiring, or the switch adjustment.
BTW check the wiring of the plug you show also. That one has to be completely un-pinned to fully dissasemble and rebuild the column.
Since you have a rebuilt column, that stuff has been taken apart. Who knows if stuff got reconnected or adjusted correctly?
Last edited by leigh1322; Jul 21, 2025 at 11:36 PM.
Here is my 72 tilt column which just got rebuilt:
This wire loom clips in to the other side (bottom) of the column. The rectangular switch bolts to the top.
Here is my 72 tilt column which just got rebuilt:
This wire loom clips in to the other side (bottom) of the column. The rectangular switch bolts to the top.
Color coding
Ignition switch connectors. Harness still in car.
Thanks guys, I’ll check things out with the multimeter and report back.
Specs:
4 speed trans.
71 LS5 pretty much stock other than a mild roller cam.
Dist overhauled, timing, dwell set.
Clean stock plugs and new plug harness.
Carb just back from Lars and installed.
Stock exhaust
The engine was built about nine years ago by a very reputable builder and ran very well on the dyno 398hp and 470 torque.
This car only has a few road miles since frame on restoration.
My issue is the engine is flat and doesn’t pick up rpm as it should. The carb was overhauled by Lars about eight years ago so I recently sent it back after finding a fair amount of debris in the filter at the carb fuel inlet. After today’s test drive it’s still not picking up rpm as it should. It has a new fuel tank and it looks clear. It has a fairly new fuel pump on the car but I haven’t verified fuel pressure and flow. I’m not sure what direction to go next.
KC
So, I wanted to “close out” this tread as the issue had been identified (by members) and isolated, many thanks to everyone for their time and experience!
I haven't yet identified the cause of the over voltage to my coil plus side “resistance” wire (nearly battery voltage while running) but the temporary fix is listed below. I’ll troubleshoot the over voltage as time permits, it’s interesting that the resistance wire voltage dropped to around 10.3 volts when the engine was fully up to temperature.
1. New points (probably arced from overvoltage).
2. Recheck dwell
3. Recheck timing (per Lars email)
4. re adjust carb idle screws
We currently have a very high density altitude but the engine is running about 95% of its potential. Probably fairly impressive this fall.
KC
